Re: [linus:master] [shmem] a2e459555c: aim9.disk_src.ops_per_sec -19.0% regression

[Chuck Lever III <chuck.lever@oracle.com>]

> On Sep 11, 2023, at 9:25 PM, Oliver Sang <oliver.sang@intel.com> wrote:
> 
> hi, Chuck Lever,
> 
> On Fri, Sep 08, 2023 at 02:43:22PM +0000, Chuck Lever III wrote:
>> 
>> 
>>> On Sep 8, 2023, at 1:26 AM, kernel test robot <oliver.sang@intel.com> wrote:
>>> 
>>> 
>>> 
>>> Hello,
>>> 
>>> kernel test robot noticed a -19.0% regression of aim9.disk_src.ops_per_sec on:
>>> 
>>> 
>>> commit: a2e459555c5f9da3e619b7e47a63f98574dc75f1 ("shmem: stable directory offsets")
>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>>> 
>>> testcase: aim9
>>> test machine: 48 threads 2 sockets Intel(R) Xeon(R) CPU E5-2697 v2 @ 2.70GHz (Ivy Bridge-EP) with 112G memory
>>> parameters:
>>> 
>>> testtime: 300s
>>> test: disk_src
>>> cpufreq_governor: performance
>>> 
>>> 
>>> In addition to that, the commit also has significant impact on the following tests:
>>> 
>>> +------------------+-------------------------------------------------------------------------------------------------+
>>> | testcase: change | aim9: aim9.disk_src.ops_per_sec -14.6% regression                                               |
>>> | test machine     | 48 threads 2 sockets Intel(R) Xeon(R) CPU E5-2697 v2 @ 2.70GHz (Ivy Bridge-EP) with 112G memory |
>>> | test parameters  | cpufreq_governor=performance                                                                    |
>>> |                  | test=all                                                                                        |
>>> |                  | testtime=5s                                                                                     |
>>> +------------------+-------------------------------------------------------------------------------------------------+
>>> 
>>> 
>>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>>> the same patch/commit), kindly add following tags
>>> | Reported-by: kernel test robot <oliver.sang@intel.com>
>>> | Closes: https://lore.kernel.org/oe-lkp/202309081306.3ecb3734-oliver.sang@intel.com
>> 
>> Hi, several weeks ago we requested that these tests be run
>> again by the robot because they can't be run in environments
>> I have available to me (the tests do not run on Fedora, and
>> I don't have any big iron).
>> 
>> We wanted the tests rerun before the patch was committed.
>> There was a deafening silence. So I assumed the work I did
>> then to address the regression was successful, and the
>> patches are now in upstream Linux.
>> 
>> This new report is disappointing.
> 
> I'm so sorry that I missed the test request for
> https://lore.kernel.org/all/169030957098.157536.9938425508695693348.stgit@manet.1015granger.net/
> 
> just FYI, when this auto-bisect done,
> head commit of linus/master: [65d6e954e37872fd9afb5ef3fc0481bb3c2f20f4] was
> tested, it already includes
> 2be4f05af71bb libfs: Remove parent dentry locking in offset_iterate_dir()
> 
> in our tests, the regression still exists.

Thanks for clarifying. I wondered about that, of course only just
after clicking "Send".


>> But, I'm still in a position where I can't run this test,
>> and the results don't really indicate where the problem
>> is. So I can't possibly address this issue.
>> 
>> Any suggestions, advice, or help would be appreciated.
> 
> if you have further fix patch, could you let us know? I will test it.

Well that's the problem. Since I can't run the reproducer, there's
nothing I can do to troubleshoot the problem myself.

Is there any hope in getting this reproducer to run on Fedora?


--
Chuck Lever