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author | Wanpeng Li <wanpeng.li@hotmail.com> | 2016-06-13 18:32:45 +0800 |
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committer | Ingo Molnar <mingo@kernel.org> | 2016-06-14 11:13:15 +0200 |
commit | 3d89e5478bf550a50c99e93adf659369798263b0 (patch) | |
tree | ed64193221dbc18db91101aa6a060a710d986c52 /drivers/bus | |
parent | 2348140d58f4f4245e9635ea8f1a77e940a4d877 (diff) | |
download | linux-3d89e5478bf550a50c99e93adf659369798263b0.tar.bz2 |
sched/cputime: Fix prev steal time accouting during CPU hotplug
Commit:
e9532e69b8d1 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")
... set rq->prev_* to 0 after a CPU hotplug comes back, in order to
fix the case where (after CPU hotplug) steal time is smaller than
rq->prev_steal_time.
However, this should never happen. Steal time was only smaller because of the
KVM-specific bug fixed by the previous patch. Worse, the previous patch
triggers a bug on CPU hot-unplug/plug operation: because
rq->prev_steal_time is cleared, all of the CPU's past steal time will be
accounted again on hot-plug.
Since the root cause has been fixed, we can just revert commit e9532e69b8d1.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 'commit e9532e69b8d1 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")'
Link: http://lkml.kernel.org/r/1465813966-3116-3-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/bus')
0 files changed, 0 insertions, 0 deletions