diff options
| author | Rik van Riel <riel@redhat.com> | 2017-06-23 12:55:28 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-12 16:55:25 +0200 |
| commit | 5a51f2febca9b47d62ae7a97089d2fd2e80ee600 (patch) | |
| tree | edd61d100d59a1479ab4da4afb972fc721bb6e22 /kernel | |
| parent | 6cd951eefda55cbbd4f638ec0f0cb173e4d3e4b9 (diff) | |
sched/fair: Simplify wake_affine() for the single socket case
commit 7d894e6e34a5cdd12309c7e4a3f830277ad4b7bf upstream.
Then 'this_cpu' and 'prev_cpu' are in the same socket, select_idle_sibling()
will do its thing regardless of the return value of wake_affine().
Just return true and don't look at all the other things.
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jhladky@redhat.com
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20170623165530.22514-3-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 58f2228f4820..c4be6e7e1a33 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5399,6 +5399,13 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, this_load = target_load(this_cpu, idx); /* + * Common case: CPUs are in the same socket, and select_idle_sibling() + * will do its thing regardless of what we return: + */ + if (cpus_share_cache(prev_cpu, this_cpu)) + return true; + + /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load * of the current CPU: @@ -5986,11 +5993,15 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (affine_sd) { sd = NULL; /* Prefer wake_affine over balance flags */ - if (cpu != prev_cpu && wake_affine(affine_sd, p, prev_cpu, sync)) + if (cpu == prev_cpu) + goto pick_cpu; + + if (wake_affine(affine_sd, p, prev_cpu, sync)) new_cpu = cpu; } if (!sd) { + pick_cpu: if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); |