Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all \u003cpre\u003e\u003ccode\u003e blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks"); } } catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); } })(); (function(){ try { var __m = "github.com"; var __re = new RegExp('^' + "github\\.com" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix"); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length \u003e 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms"); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links"); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default"); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers"); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode"); } } catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); } })(); })();
Skip to content

Implement fake hot/cold splitting and corresponding stress mode#69763

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 3 commits into from
May 27, 2022
Merged

Implement fake hot/cold splitting and corresponding stress mode #69763

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
564c75d
Implemented fake code splitting in JIT for testing without VM
May 17, 2022
a0e2c49
Merge branch 'main' of github.com:amanasifkhalid/runtime into hot-col…
May 23, 2022
5965366
Implement stress mode for hot/cold splitting
May 24, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3186,14 +3186,18 @@ void Compiler::compInitOptions(JitFlags* jitFlags)

opts.compReloc = jitFlags->IsSet(JitFlags::JIT_FLAG_RELOC);

bool enableFakeSplitting = false;

#ifdef DEBUG
enableFakeSplitting = JitConfig.JitFakeProcedureSplitting();

#if defined(TARGET_XARCH)
// Whether encoding of absolute addr as PC-rel offset is enabled
opts.compEnablePCRelAddr = (JitConfig.EnablePCRelAddr() != 0);
#endif
#endif // DEBUG

opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT);
opts.compProcedureSplitting = jitFlags->IsSet(JitFlags::JIT_FLAG_PROCSPLIT) || enableFakeSplitting;

#ifdef TARGET_ARM64
// TODO-ARM64-NYI: enable hot/cold splitting
Expand All@@ -3207,7 +3211,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
if (opts.compProcedureSplitting)
{
// Note that opts.compdbgCode is true under ngen for checked assemblies!
opts.compProcedureSplitting = !opts.compDbgCode;
opts.compProcedureSplitting = !opts.compDbgCode || enableFakeSplitting;

#ifdef DEBUG
// JitForceProcedureSplitting is used to force procedure splitting on checked assemblies.
Expand DownExpand Up@@ -3236,6 +3240,7 @@ void Compiler::compInitOptions(JitFlags* jitFlags)
}

#ifdef DEBUG

// Now, set compMaxUncheckedOffsetForNullObject for STRESS_NULL_OBJECT_CHECK
if (compStressCompile(STRESS_NULL_OBJECT_CHECK, 30))
{
Expand DownExpand Up@@ -5185,6 +5190,9 @@ void Compiler::placeLoopAlignInstructions()

if ((block->bbNext != nullptr) && (block->bbNext->isLoopAlign()))
{
// Loop alignment is disabled for cold blocks
assert((block->bbFlags & BBF_COLD) == 0);

// If jmp was not found, then block before the loop start is where align instruction will be added.
if (bbHavingAlign == nullptr)
{
Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -7613,6 +7613,8 @@ class Compiler

// ICorJitInfo wrappers

void eeAllocMem(AllocMemArgs* args);

void eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize);

void eeAllocUnwindInfo(BYTE* pHotCode,
Expand Down
45 changes: 45 additions & 0 deletions src/coreclr/jit/ee_il_dll.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1122,6 +1122,37 @@ void Compiler::eeDispLineInfos()
* (e.g., host AMD64, target ARM64), then VM will get confused anyway.
*/

void Compiler::eeAllocMem(AllocMemArgs* args)
{
#ifdef DEBUG
// Fake splitting implementation: hot section = hot code + 4K buffer + cold code
const UNATIVE_OFFSET hotSizeRequest = args->hotCodeSize;
const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
const UNATIVE_OFFSET fakeSplittingBuffer = 4096;

if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
args->hotCodeSize = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
args->coldCodeSize = 0;
}
#endif

info.compCompHnd->allocMem(args);

#ifdef DEBUG
if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
{
// Fix up hot/cold code pointers
args->coldCodeBlock = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;

// Reset args' hot/cold code sizes in case caller reads them later
args->hotCodeSize = hotSizeRequest;
args->coldCodeSize = coldSizeRequest;
}
#endif
}

void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwindSize)
{
#ifdef DEBUG
Expand All@@ -1130,6 +1161,13 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
isColdCode ? "true" : "false", unwindSize);
}

// Fake splitting currently does not handle unwind info for cold code
if (isColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand DownExpand Up@@ -1169,6 +1207,13 @@ void Compiler::eeAllocUnwindInfo(BYTE* pHotCode,
}
printf(")\n");
}

// Fake splitting currently does not handle unwind info for cold code
if (pColdCode && JitConfig.JitFakeProcedureSplitting())
{
JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
return;
}
#endif // DEBUG

if (info.compMatchedVM)
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/emit.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6065,7 +6065,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand All@@ -6083,7 +6083,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
args.xcptnsCount = xcptnsCount;
args.flag = allocMemFlag;

emitCmpHandle->allocMem(&args);
emitComp->eeAllocMem(&args);

codeBlock = (BYTE*)args.hotCodeBlock;
codeBlockRW = (BYTE*)args.hotCodeBlockRW;
Expand DownExpand Up@@ -6337,6 +6337,7 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
assert(coldCodeBlock);
cp = coldCodeBlock;
writeableOffset = coldCodeBlockRW - coldCodeBlock;
emitOffsAdj = 0;
#ifdef DEBUG
if (emitComp->opts.disAsm || emitComp->verbose)
{
Expand Down
5 changes: 3 additions & 2 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -5963,9 +5963,10 @@ bool Compiler::fgUpdateFlowGraph(bool doTailDuplication)
(bNext != nullptr) && // block is not the last block
(bNext->bbRefs == 1) && // No other block jumps to bNext
(bNext->bbJumpKind == BBJ_ALWAYS) && // The next block is a BBJ_ALWAYS block
bNext->isEmpty() && // and it is an an empty block
bNext->isEmpty() && // and it is an empty block
(bNext != bNext->bbJumpDest) && // special case for self jumps
(bDest != fgFirstColdBlock))
(bDest != fgFirstColdBlock) &&
(!fgInDifferentRegions(block, bDest))) // do not cross hot/cold sections
{
// case (a)
//
Expand Down
87 changes: 52 additions & 35 deletions src/coreclr/jit/flowgraph.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3414,49 +3414,64 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
BasicBlock* block;
BasicBlock* lblk;

for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
bool blockMustBeInHotSection = false;
bool forceSplit = false;

#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
blockMustBeInHotSection = true;
}
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
#ifdef DEBUG
// If stress-splitting, split right after the first block; don't handle functions with EH
forceSplit = JitConfig.JitStressProcedureSplitting() && (compHndBBtabCount == 0);
#endif

// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
if (forceSplit)
{
firstColdBlock = fgFirstBB->bbNext;
prevToFirstColdBlock = fgFirstBB;
}
else
{
for (lblk = nullptr, block = fgFirstBB; block != nullptr; lblk = block, block = block->bbNext)
{
// We have a candidate for first cold block
bool blockMustBeInHotSection = false;

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
#if HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION
if (bbIsHandlerBeg(block))
{
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
blockMustBeInHotSection = true;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block
#endif // HANDLER_ENTRY_MUST_BE_IN_HOT_SECTION

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
// Do we have a candidate for the first cold block?
if (firstColdBlock != nullptr)
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
// We have a candidate for first cold block

// Is this a hot block?
if (blockMustBeInHotSection || (block->isRunRarely() == false))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
// We have to restart the search for the first cold block
firstColdBlock = nullptr;
prevToFirstColdBlock = nullptr;
}
}
else // (firstColdBlock == NULL)
{
// We don't have a candidate for first cold block

// Is this a cold block?
if (!blockMustBeInHotSection && (block->isRunRarely() == true))
{
//
// If the last block that was hot was a BBJ_COND
// then we will have to add an unconditional jump
// so the code size for block needs be large
// enough to make it worth our while
//
if ((lblk == nullptr) || (lblk->bbJumpKind != BBJ_COND) || (fgGetCodeEstimate(block) >= 8))
{
// This block is now a candidate for first cold block
// Also remember the predecessor to this block
firstColdBlock = block;
prevToFirstColdBlock = lblk;
}
}
}
}
Expand All@@ -3483,8 +3498,9 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
// then it may not be worth it to move it
// into the Cold section as a jump to the
// Cold section is 5 bytes in size.
// Ignore if stress-splitting.
//
if (firstColdBlock->bbNext == nullptr)
if (!forceSplit && firstColdBlock->bbNext == nullptr)
{
// If the size of the cold block is 7 or less
// then we will keep it in the Hot section.
Expand DownExpand Up@@ -3557,6 +3573,7 @@ PhaseStatus Compiler::fgDetermineFirstColdBlock()
for (block = firstColdBlock; block != nullptr; block = block->bbNext)
{
block->bbFlags |= BBF_COLD;
block->unmarkLoopAlign(this DEBUG_ARG("Loop alignment disabled for cold blocks"));
}

EXIT:;
Expand Down
9 changes: 9 additions & 0 deletions src/coreclr/jit/jitconfigvalues.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -164,6 +164,9 @@ CONFIG_INTEGER(JitStressBiasedCSE, W("JitStressBiasedCSE"), 0x101) // Intern
// stress.
CONFIG_INTEGER(JitStressModeNamesOnly, W("JitStressModeNamesOnly"), 0) // Internal Jit stress: if nonzero, only enable
// stress modes listed in JitStressModeNames
CONFIG_INTEGER(JitStressProcedureSplitting, W("JitStressProcedureSplitting"), 0) // Always split after the first basic
// block. Skips functions with EH
// for simplicity.
CONFIG_INTEGER(JitStressRegs, W("JitStressRegs"), 0)
CONFIG_STRING(JitStressRegsRange, W("JitStressRegsRange")) // Only apply JitStressRegs to methods in this hash range

Expand DownExpand Up@@ -192,6 +195,12 @@ CONFIG_INTEGER(JitDumpAtOSROffset, W("JitDumpAtOSROffset"), -1) // Only dump OSR
CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline compiler phases
CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
CONFIG_METHODSET(JitExclude, W("JitExclude"))
CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
// For now, this disables unwind info for
// cold sections, breaking stack walks.
// Set COMPlus_GCgen0size=1000000 to avoid
// running the GC, which requires
// stack-walking.
CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))
Expand Down