sched/fair: Modify the comment about lock assumptions in migrate_task_rq_fair()

The comment describing migrate_task_rq_fair() says that the caller
should hold p->pi_lock. But in some cases the caller can hold
task_rq(p)->lock instead of p->pi_lock. So the comment is broken and
this patch fixes it.

Signed-off-by: Byungchul Park <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Byungchul Park 2015-11-18 09:34:59 +09:00 • committed by Ingo Molnar
commit 525628c73b

View file

@ -5058,8 +5058,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
/*
* Called immediately before a task is migrated to a new cpu; task_cpu(p) and
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous cpu. However, the caller only guarantees p->pi_lock is held; no
* other assumptions, including the state of rq->lock, should be made.
* previous cpu. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
static void migrate_task_rq_fair(struct task_struct *p)
{