[tip:sched/urgent] sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()

tip-bot for Mike Galbraith
2009-09-19T15:17:17Z

Commit-ID: 3f04e8cd5b24727a2500f8ab8f3de730ba47b02c
Gitweb: http://git.kernel.org/tip/3f04e8cd5b24727a2500f8ab8f3de730ba47b02c
Author: Mike Galbraith <efault@gmx.de>
AuthorDate: Sat, 19 Sep 2009 16:52:35 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 19 Sep 2009 17:11:31 +0200

sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()

While doing some testing, I pinned mplayer, only to find it
following X around like a puppy. Looking at commit c88d591, I found
a cpu_allowed check that went AWOL. I plugged it back in where it
looks like it needs to go, and now when I say "sit, stay!", mplayer
obeys again.

'c88d591 sched: Merge select_task_rq_fair() and
sched_balance_self()' accidentally dropped the check, causing
wake_affine() to pull pinned tasks - put it back.

[ v2: use a cheaper version from Peter ]

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
kernel/sched_fair.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 29b35a7..566e3bb 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1339,7 +1339,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
int sync = wake_flags & WF_SYNC;

if (sd_flag & SD_BALANCE_WAKE) {
- if (sched_feat(AFFINE_WAKEUPS))
+ if (sched_feat(AFFINE_WAKEUPS) &&
+ cpumask_test_cpu(cpu, &p->cpus_allowed))
want_affine = 1;
new_cpu = prev_cpu;
}