Re: [PATCH -mm 0/6] cgroup: block device i/o controller (v11)
From: Andrea Righi
Date: Tue Oct 14 2008 - 05:56:33 EST
Dong-Jae Kang wrote:
> Hi, Andrea
>
> thank you for your contribution to community
> these days, I am testing several IO controllers in container ML,
> dm-ioband by Ryo tsuruta(v1.7.0), 2-Layer CFQ by Satoshi and your
> io-throttle(v11)
Thanks! this is surely a valuable task.
>
> I have several question about io-throttle
> below is my test reusult of io-throttle(v11) with xdd 6.5
> But, I think I have something wrong, as showed in result
> In direct IO mode, Only read operation was controlled by io-throttle
> Can you check my test procedure and result and comments to me about that
Your procedure is correct. Anyway, you found a known bug in io-throttle
v11. If you want to properly use it you need to mount the memory
controller together with blockio, since currently blockio depends on it
to retrieve the owner of a page during writes in submit_bio().
As reported in:
[PATCH -mm 4/6] memcg: interface to charge the right cgroup of asynchronous i/o activity
this is no more than a hack and in perspective a more generic framework
able to provide this functionality should be used (i.e. bio-cgroup).
I'll fix this issue in the next version of io-throttle (probably I'll
try to rewrite io-throttle on top of bio-cgroup), but for now the
workaround is to mount the cgroupfs using -o blockio,memory (at least).
>
> additionally, your testing shell script(run_io_throttle_test.sh) for
> io-throttle was not updated for new io-throttle
> so, it could be operated after I fixed it
The testing of iops limiting is not yet implemented and I don't have a
very good testcase for this, but I can share with you a small script that
I'm using to check if iops limiting is working or not, if you're interested.
Thanks,
-Andrea
>
> -----------------------------------------------------------------------------------
> - Test System Information
>
> Computer Name, localhost.localdomain, User Name, root
> OS release and version, Linux 2.6.27-rc5-mm1 #1 SMP Thu Oct 9 18:27:09 KST 2008
> Machine hardware type, i686
> Number of processors on this system, 1
> Page size in bytes, 4096
> Number of physical pages, 515885
> Megabytes of physical memory, 2015
> Target[0] Q[0], /dev/sdb
> Per-pass time limit in seconds, 30
> Blocksize in bytes, 512
> Request size, 128, blocks, 65536, bytes
> Number of Requests, 16384
> Number of MegaBytes, 512 or 1024
> Direct I/O, disabled or enable
> Seek pattern, sequential
> Queue Depth, 1
>
> - Test Procedure
>
> ï mkdir /dev/blockioctl
> ï mount -t cgroup -o blockio cgroup /dev/blockioctl
> ï mkdir /dev/blockioctl/cgroup-1
> ï mkdir /dev/blockioctl/cgroup-2
> ï mkdir /dev/blockioctl/cgroup-3
> ï echo /dev/sdb:$((1024*1024)):0:0 >
> /dev/blockioctl/cgroup-1/blockio.bandwidth-max
> ï echo /dev/sdb:$((2*1024*1024)):0:0 >
> /dev/blockioctl/cgroup-2/blockio.bandwidth-max
> ï echo /dev/sdb:$((3*1024*1024)):0:0 >
> /dev/blockioctl/cgroup-3/blockio.bandwidth-max
> ï in terminal 1, echo $$ > /dev/blockioctl/cgroup-1/tasks
> ï in terminal 2, echo $$ > /dev/blockioctl/cgroup-2/tasks
> ï in terminal 3, echo $$ > /dev/blockioctl/cgroup-3/tasks
> ï in each terminal, xdd.linux -op write( or read ) -targets 1 /dev/sdb
> -blocksize 512 -reqsize 128 -mbytes 1024( or 512 ) -timelimit 30
> -verbose âdio(enable or disable)
>
> - setting status information
>
> [root@localhost blockioctl]# cat ./cgroup-1/blockio.bandwidth-max
> 8 16 1048576 0 0 0 13016
> [root@localhost blockioctl]# cat ./cgroup-2/blockio.bandwidth-max
> 8 16 2097152 0 0 0 11763
> [root@localhost blockioctl]# cat ./cgroup-3/blockio.bandwidth-max
> 8 16 3145728 0 0 0 11133
>
> - Test Result
> xdd.linux -op read -targets 1 /dev/sdb -blocksize 512 -reqsize 128
> -mbytes 512 -timelimit 30 -dio -verbose
>
> cgroup-1
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 31522816 481 30.005 1.051 16.03 0.0624
> 0.00 read 65536
> 0 1 31522816 481 30.005 1.051 16.03 0.0624
> 0.00 read 65536
> 1 1 31522816 481 30.005 1.051 16.03 0.0624
> 0.00 read 65536
>
> cgroup-2
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 62980096 961 30.001 2.099 32.03 0.0312
> 0.00 read 65536
> 0 1 62980096 961 30.001 2.099 32.03 0.0312
> 0.00 read 65536
> 1 1 62980096 961 30.001 2.099 32.03 0.0312
> 0.00 read 65536
>
> cgroup-3
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 94437376 1441 30.003 3.148 48.03 0.0208
> 0.00 read 65536
> 0 1 94437376 1441 30.003 3.148 48.03 0.0208
> 0.00 read 65536
> 1 1 94437376 1441 30.003 3.148 48.03 0.0208
> 0.00 read 65536
>
> xdd.linux -op write -targets 1 /dev/sdb -blocksize 512 -reqsize 128
> -mbytes 512 -timelimit 30 -dio âverbose
>
> cgroup-1
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 640221184 9769 30.097 21.272 324.58 0.0031
> 0.00 write 65536
> 0 1 640221184 9769 30.097 21.272 324.58 0.0031
> 0.00 write 65536
> 1 1 640221184 9769 30.097 21.272 324.58 0.0031
> 0.00 write 65536
>
> cgroup-2
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 633798656 9671 30.001 21.126 322.36 0.0031
> 0.00 write 65536
> 0 1 633798656 9671 30.001 21.126 322.36 0.0031
> 0.00 write 65536
> 1 1 633798656 9671 30.001 21.126 322.36 0.0031
> 0.00 write 65536
>
> cgroup-3
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 630652928 9623 30.001 21.021 320.76 0.0031
> 0.00 write 65536
> 0 1 630652928 9623 30.001 21.021 320.76 0.0031
> 0.00 write 65536
> 1 1 630652928 9623 30.001 21.021 320.76 0.0031
> 0.00 write 65536
>
> xdd.linux -op read -targets 1 /dev/sdb -blocksize 512 -reqsize 128
> -mbytes 1024 -timelimit 30 -verbose
>
> cgroup-1
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 70123520 1070 30.150 2.326 35.49 0.0282
> 0.00 read 65536
> 0 1 70123520 1070 30.150 2.326 35.49 0.0282
> 0.00 read 65536
> 1 1 70123520 1070 30.150 2.326 35.49 0.0282
> 0.00 read 65536
>
> cgroup-2
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 70844416 1081 30.063 2.357 35.96 0.0278
> 0.00 read 65536
> 0 1 70844416 1081 30.063 2.357 35.96 0.0278
> 0.00 read 65536
> 1 1 70844416 1081 30.063 2.357 35.96 0.0278
> 0.00 read 65536
>
> cgroup-3
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 72155136 1101 30.204 2.389 36.45 0.0274
> 0.00 read 65536
> 0 1 72155136 1101 30.204 2.389 36.45 0.0274
> 0.00 read 65536
> 1 1 72155136 1101 30.204 2.389 36.45 0.0274
> 0.00 read 65536
>
> xdd.linux -op write -targets 1 /dev/sdb -blocksize 512 -reqsize 128
> -mbytes 1024 -timelimit 30 -verbose
>
> cgroup-1
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 818610176 12491 30.031 27.258 415.93 0.0024
> 0.00 write 65536
> 0 1 818610176 12491 30.031 27.258 415.93 0.0024
> 0.00 write 65536
> 1 1 818610176 12491 30.031 27.258 415.93 0.0024
> 0.00 write 65536
>
> cgroup-2
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 848494592 12947 30.066 28.221 430.62 0.0023
> 0.00 write 65536
> 0 1 848494592 12947 30.066 28.221 430.62 0.0023
> 0.00 write 65536
> 1 1 848494592 12947 30.066 28.221 430.62 0.0023
> 0.00 write 65536
>
> cgroup-3
>
> T Q Bytes Ops Time Rate IOPS Latency
> %CPU OP_Type ReqSize
> 0 1 786563072 12002 30.078 26.151 399.03 0.0025
> 0.00 write 65536
> 0 1 786563072 12002 30.078 26.151 399.03 0.0025
> 0.00 write 65536
> 1 1 786563072 12002 30.078 26.151 399.03 0.0025
> 0.00 write 65536
>
> Best Regards,
> Dong-Jae Kang
>
>
> 2008/10/7 Andrea Righi <righi.andrea@xxxxxxxxx>:
>> The objective of the i/o controller is to improve i/o performance
>> predictability of different cgroups sharing the same block devices.
>>
>> Respect to other priority/weight-based solutions the approach used by this
>> controller is to explicitly choke applications' requests that directly (or
>> indirectly) generate i/o activity in the system.
>>
>> The direct bandwidth and/or iops limiting method has the advantage of improving
>> the performance predictability at the cost of reducing, in general, the overall
>> performance of the system (in terms of throughput).
>>
>> Detailed informations about design, its goal and usage are described in the
>> documentation.
>>
>> Patchset against 2.6.27-rc5-mm1:
>>
>> [PATCH 0/6] cgroup: block device i/o controller (v11)
>> [PATCH 1/6] i/o controller documentation
>> [PATCH 2/6] introduce ratelimiting attributes and functionality to res_counter
>> [PATCH 3/6] i/o controller infrastructure
>> [PATCH 4/6] memcg: interface to charge the right cgroup of asynchronous i/o activity
>> [PATCH 5/6] i/o controller instrumentation: accounting and throttling
>> [PATCH 6/6] export per-task i/o throttling statistics to userspace
>>
>> The all-in-one patch (and previous versions) can be found at:
>> http://download.systemimager.org/~arighi/linux/patches/io-throttle/
>>
>> There are no significant changes respect to v10, I've only implemented/fixed
>> some suggestions I received.
>>
>> Changelog: (v10 -> v11)
>>
>> * report per block device i/o statistics (total bytes read/written and iops)
>> in blockio.stat for i/o limited cgroups
>> * distinct bandwidth and iops statistics: both in blockio.throttlecnt and
>> /proc/PID/io-throttle-stat (suggested by David Radford)
>> * merge res_counter_ratelimit functionality into res_counter, to avoid code
>> duplication (suggested by Paul Manage)
>> * use kernel-doc style for documenting struct res_counter attributes
>> (suggested by Randy Dunalp)
>> * udpated documentation
>>
>> Thanks to all for the feedback!
>> -Andrea
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