Messages in this thread | | | Subject | Re: 2.6.25-rc4-git3: Reported regressions from 2.6.24 | From | "Zhang, Yanmin" <> | Date | Wed, 12 Mar 2008 16:48:15 +0800 |
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On Mon, 2008-03-10 at 01:32 +0100, Rafael J. Wysocki wrote: > [Due to the lack of time for reviewing all of the email threads related to the > regressions marked as "unresolved" below, I might have missed some patches > fixing them. If you are involved in debugging/fixing any of them, please let > me know if I should update the list. Thanks!] > > This message contains a list of some regressions from 2.6.24 reported since > 2.6.25-rc1 was released, for which there are no fixes in the mainline I know > of. If any of them have been fixed already, please let me know. > > If you know of any other unresolved regressions from 2.6.24, please let me know > either and I'll add them to the list. Also, please let me know if any of the > entries below are invalid. > > > Listed regressions statistics: > > Date Total Pending Unresolved > ---------------------------------------- > 2008-03-10 138 66 47 > 2008-03-03 115 65 49 > 2008-02-25 90 51 39 > 2008-02-17 61 45 37 > > > Unresolved regressions > ---------------------- > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=9978 > Subject : 2.6.25-rc1: volanoMark 45% regression > Submitter : Zhang, Yanmin <yanmin_zhang@linux.intel.com> > Date : 2008-02-13 10:30 > References : http://lkml.org/lkml/2008/2/13/128 > Handled-By : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> > Balbir Singh <balbir@linux.vnet.ibm.com> Peter reverted the load balance patch and 2.6.25-rc4 accepted the reverting patch.
With kernel 2.6.25-rc5, volanoMark has about 6% regression on my 16-core tigerton. If I apply patch http://lkml.org/lkml/2008/2/20/83 which fixes the tbench regression issue, volanoMark regression becomes about 4%.
I tried to bisect down which patch caused the last 4%, but found it's very hard. One thing is many patches depend on the reverted patches. The other thing is I find the testing result isn't stable since 2.6.25-rc1. The result variation might be more than 15% sometimes. I ran the testing against the same kernel for many times to get the best result.
I also tried to tune some sched_XXX parameters under /proc/sys/kernel, but didn't get better result than the default configuration.
Above regression exists on the 2.93GHz 16-core tigerton. With the less powerful 2.40GHz 16-core tigerton, the regression is less than 1%, but result is not stable and results of many runs might have about 15% variation.
On 8-core stoakley, the regression is about 1%.
Sorry for the late update.
-yanmin
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