Messages in this thread | | | Subject | Re: 2.6.32.y stable kernel regression with taskset | From | Mike Galbraith <> | Date | Thu, 16 Sep 2010 05:45:12 +0200 |
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On Wed, 2010-09-15 at 11:47 -0700, Yinghai Lu wrote: > found problem with cpuscaling test. > > Under 2.6.32.21 Userspace gov > min freq load test time is nearly the same as max freq load test time around ~16 seconds > > under 2.6.18-194 > min freq load test time is ~40 seconds > max freq load test time is ~ 17 seconds > > the test is > 1. set governor for one cpu to userspace > 2. set freq to min for that cpu > 3. using taskset to put load test only on that cpu, and get the time for load test. > > so that mean taskset did not put load test on cpu that we want. and other cpu still have ondemand governor and load test get done much faster > > git bisect report: > > c6fc81afa2d7ef2f775e48672693d8a0a8a7325d is the first bad commit > commit c6fc81afa2d7ef2f775e48672693d8a0a8a7325d > Author: John Wright <john.wright@hp.com> > Date: Tue Apr 13 16:55:37 2010 -0600 > > sched: Fix a race between ttwu() and migrate_task()
Known issue. There's a sched series for 32-stable in the pipeline.
-Mike
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