Messages in this thread | | | Date | Thu, 22 May 2008 22:04:38 +0900 (JST) | Subject | Re: [RFC][v2][patch 0/12][CFQ-cgroup]Yet another I/O bandwidth controlling subsystem for CGroups based on CFQ | From | Ryo Tsuruta <> |
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Hi Uchida-san,
I realized that the benchmark results which I posted on Apr 25 had some problems with the testing environment.
From: Ryo Tsuruta <ryov@valinux.co.jp> Subject: Re: [RFC][v2][patch 0/12][CFQ-cgroup]Yet another I/O bandwidth controlling subsystem for CGroups based on CFQ Date: Fri, 25 Apr 2008 18:54:44 +0900 (JST)
Uchida-san said,
> In the test #2 and #3, did you use direct write? > I guess you have used the non-direct write I/O (using cache).
I answered "Yes," but actually I did not use direct write I/O, because I ran these tests on Xen-HVM. Xen-HVM backend driver doesn't use direct I/O for actual disk operations even though guest OS uses direct I/O.
An another problem was that the CPU time was used up during the tests.
So, I retested with the new testing environment and got good results. The number of I/Os is proportioned according to the priority levels.
Details of the tests are as follows:
Envirionment: Linux version 2.6.25-rc2-mm1 based. CPU0: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz stepping 06 CPU1: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz stepping 06 Memory: 2063568k/2088576k available (2085k kernel code, 23684k reserved, 911k data, 240k init, 1171072k highmem) scsi 1:0:0:0: Direct-Access ATA WDC WD2500JS-55N 10.0 PQ: 0 ANSI: 5 sd 1:0:0:0: [sdb] 488397168 512-byte hardware sectors (250059 MB) sd 1:0:0:0: [sdb] Write Protect is off sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00 sd 1:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 sdb6 sdb7 sdb8 sdb9 sdb10 sdb11 sdb12 sdb13 sdb14 sdb15 >
Procedures: o Prepare 3 partitions sdb5, sdb6 and sdb7. o Run 100 processes issuing random direct I/O with 4KB data on each partitions. o Run 3 tests: #1 issuing read I/O only. #2 issuing write I/O only. #3 sdb5 and sdb6 are read, sdb7 is write. o Count up the number of I/Os which have done in 60 seconds.
Results: Vasily's scheduler The number of I/Os (percentage to total I/Os) --------------------------------------------------------------------- | partition | sdb5 | sdb6 | sdb7 | total | | priority | 7(highest) | 4 | 0(lowest) | I/Os | |---------------+--------------+--------------+--------------|--------| | #1 read | 3383(35%) | 3164(33%) | 3142(32%) | 9689 | | #2 write | 3017(42%) | 2372(33%) | 1851(26%) | 7240 | | #3 read&write | 4300(36%) | 3127(27%) | 1521(17%) | 8948 | ---------------------------------------------------------------------
Satoshi's scheduler The number of I/Os (percentage to total I/O) --------------------------------------------------------------------- | partition | sdb5 | sdb6 | sdb7 | total | | priority | 0(highest) | 4 | 7(lowest) | I/Os | |---------------+--------------+--------------+--------------|--------| | #1 read | 3907(47%) | 3126(38%) | 1260(15%) | 8293 | | #2 write | 3389(41%) | 3024(36%) | 1901(23%) | 8314 | | #3 read&write | 5028(53%) | 3961(42%) | 441( 5%) | 9430 | ---------------------------------------------------------------------
Thanks, Ryo Tsuruta
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