Messages in this thread Patch in this message | | | Subject | [PATCH] sched: Revert 738d2be, Simplify set_task_cpu() | From | Peter Zijlstra <> | Date | Tue, 22 Dec 2009 15:43:19 +0100 |
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[ and now with Subject ]
Effectively reverts 738d2be4301007f054541c5c4bf7fb6a361c9b3a.
As demonstrated by Eric, we really need to call __set_task_cpu() early in the fork() path to properly initialize the various task state -- specifically the cgroup state through set_task_rq().
[ we could probably fix this by explicitly calling __set_task_cpu() from sched_fork(), but lets try that for the next cycle and simply revert to the old behaviour for now. ]
Reported-by: Eric Paris <eparis@redhat.com> Tested-by: Eric Paris <eparis@redhat.com>, Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> --- kernel/sched.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -2067,11 +2067,10 @@ void set_task_cpu(struct task_struct *p, trace_sched_migrate_task(p, new_cpu); - if (task_cpu(p) == new_cpu) - return; - - p->se.nr_migrations++; - perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); + if (task_cpu(p) != new_cpu) { + p->se.nr_migrations++; + perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); + } __set_task_cpu(p, new_cpu); }
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