diff options
| author | Brendan Jackman <brendan.jackman@arm.com> | 2017-08-01 15:48:37 +0100 |
|---|---|---|
| committer | Chris Redpath <chris.redpath@arm.com> | 2017-10-27 13:30:33 +0100 |
| commit | 2f30db8df4076c54f92ac2ebe26734e27c164fd3 (patch) | |
| tree | 26714cb6e63a3a2adfca0e4f07063f181fb92e11 /kernel | |
| parent | 5a8663664915417aec806da2b0bc534d675f413d (diff) | |
UPSTREAM: sched/fair: Sync task util before slow-path wakeup
We use task_util() in find_idlest_group() via capacity_spare_wake().
This task_util() updated in wake_cap(). However wake_cap() is not the
only reason for ending up in find_idlest_group() - we could have been sent
there by wake_wide(). So explicitly sync the task util with prev_cpu
when we are about to head to find_idlest_group().
We could simply do this at the beginning of
select_task_rq_fair() (i.e. irrespective of whether we're heading to
select_idle_sibling() or find_idlest_group() & co), but I didn't want to
slow down the select_idle_sibling() path more than necessary.
Don't do this during fork balancing, we won't need the task_util and
we'd just clobber the last_update_time, which is supposed to be 0.
Change-Id: I935f4bfdfec3e8b914457aac3387ce264d5fd484
Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andres Oportus <andresoportus@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/20170808095519.10077-1-brendan.jackman@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry-picked-from: commit ea16f0ea6c3d tip:sched/core)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index bf7b7a7e778b..5d8081b77f8a 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6757,6 +6757,15 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f new_cpu = cpu; } + if (sd && !(sd_flag & SD_BALANCE_FORK)) { + /* + * We're going to need the task's util for capacity_spare_wake + * in find_idlest_group. Sync it up to prev_cpu's + * last_update_time. + */ + sync_entity_load_avg(&p->se); + } + if (!sd) { if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); |