Set msize for 9p mounting

[MarioCarrilloA]

By adding the msize value (524288 bytes)
provides an enhancement in I/O storage operations.
The following results are from I/O operations such as:
read, write, random read etc...,using different block
sizes, where the x results express how many times is better.

Read

bs	random	linear
64K	6x	7x
256K	13x	17x
512K	16x	13x
64MB	14x	14x
256MB	15x	15x
512MB	14x	15x

Write

bs	random	linear
64K	3x	3x
256K	3x	3x
512K	3x	3x
64MB	3x	3x
256MB	3x	3x
512MB	3x	3x

Signed-off-by: Mario Alfredo Carrillo Arevalo mario.alfredo.c.arevalo@intel.com

[grahamwhaley]

Great, nice to see :-)
We might want to mention that the other performance metrics (network, boot times etc.) are unaffected, and there is a minor (~2%) memory footprint increase.
Patch looks good to me, but I'll give it a build/run test before I ack it here.

[jcvenegas]

Nice to have performance back! and even better \o/ 2% memory degradation for the performance improved is something is really good. looks good +1

[grahamwhaley]

built and ran file.
lgtm

[jcvenegas]

+1

[gorozco1]

Could you add comment in the code explaining why this magic number.

[gorozco1]

Could you add a comment in the code explaining why this magic number?

[MarioCarrilloA]

@gorozco1 comments added :)

[devimc]

I'd like to see the review of Chao P (or Anthony Xu). I remember he did something similar in CC 2.0 but with msize=131072

[chao-p]

I picked 128K(msize=131072) because I saw less performance increase when I use a bigger value. I suggest to compare the read/write speed in several configurations(512K vs 128K or even 64K...) to see which is better.

[MarioCarrilloA]

Hi @chao-p , I have done that experiment using several msize configuration(64K, 128K, 256K, 512K etc...), with different block sizes and I/O operations (rand read, rand write, linear read and linear write) and I got the best results with 512K :), however I do not know which tool(s) did you use for that.

[chao-p]

@MarioCarrilloA Sounds good, then please use 512K. I used pts/aio-stress in phoronix-test-suite.

[mcastelino]

We need to see the relationship between this and the backing storage block size.

For example in the case of device mapper you see that the xfs logbsize=64k. Not sure how the two will interact.

/dev/mapper/docker-253:0-1841856-edd0b562208c3c47b81b7dea03f245cb9974d6f27d374a501a9c23730fd579aa on /var/lib/docker/devicemapper/mnt/edd0b562208c3c47b81b7dea03f245cb9974d6f27d374a501a9c23730fd579aa type xfs (rw,relatime,seclabel,nouuid,attr2,inode64,logbsize=64k,sunit=128,swidth=128,noquota)