[Devel] Re: [RFC][v2][patch 0/12][CFQ-cgroup]Yet another I/O bandwidth controlling subsystem for CGroups based on CFQ

[Ryo Tsuruta]

Hi, 

I report benchmark results of the following I/O bandwidth controllers.

  From:	Vasily Tarasov <vtaras at openvz.org>
  Subject: [RFC][PATCH 0/9] cgroups: block: cfq: I/O bandwidth
           controlling subsystem for CGroups based on CFQ
  Date: Fri, 15 Feb 2008 01:53:34 -0500

  From: "Satoshi UCHIDA" <s-uchida at ap.jp.nec.com>
  Subject: [RFC][v2][patch 0/12][CFQ-cgroup]Yet another I/O bandwidth
           controlling subsystem for CGroups based on CFQ
  Date: Thu, 3 Apr 2008 16:09:12 +0900

The test procedure is as follows:
  o Prepare 3 partitions sdc2, sdc3 and sdc4.
  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 sdc2 and sdc3 are read, sdc4 is write.
  o Count up the number of I/Os which have done in 60 seconds.

Unfortunately, both bandwidth controllers didn't work as I expected,
On the test #3, the write I/O ate up the bandwidth regardless of the
specified priority level.

                          Vasily's scheduler
               The number of I/Os (percentage to total I/Os)
   ---------------------------------------------------------------------
  | partition     |     sdc2     |     sdc3     |     sdc4     | total  |
  | priority      |  7(highest)  |      4       |  0(lowest)   |  I/Os  |
  |---------------+--------------+--------------+--------------|--------|
  | #1 read       |  3620(35.6%) |  3474(34.2%) |  3065(30.2%) |  10159 |
  | #2 write      | 21985(36.6%) | 19274(32.1%) | 18856(31.4%) |  60115 |
  | #3 read&write |  5571( 7.5%) |  3253( 4.4%) | 64977(88.0%) |  73801 |
   ---------------------------------------------------------------------

                          Satoshi's scheduler
               The number of I/Os (percentage to total I/O)
   ---------------------------------------------------------------------
  | partition     |     sdc2     |     sdc3     |     sdc4     | total  |
  | priority      |  0(highest)  |      4       |  7(lowest)   |  I/Os  |
  |---------------+--------------+--------------+--------------|--------|
  | #1 read       |  4523(47.8%) |  3733(39.5%) |  1204(12.7%) |   9460 |
  | #2 write      | 65202(59.0%) | 35603(32.2%) |  9673( 8.8%) | 110478 |
  | #3 read&write |  5328(23.0%) |  4153(17.9%) | 13694(59.1%) |  23175 |
   ---------------------------------------------------------------------

I'd like to see other benchmark results if anyone has.

Thanks,
Ryo Tsuruta