From: Valentin Schneider <valentin.schneider@arm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@redhat.com, peterz@infradead.org,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com
Subject: [RFC PATCH 4/7] sched/fair: Dissociate wakeup decisions from SD flag value
Date: Wed, 11 Dec 2019 16:43:58 +0000 [thread overview]
Message-ID: <20191211164401.5013-5-valentin.schneider@arm.com> (raw)
In-Reply-To: <20191211164401.5013-1-valentin.schneider@arm.com>
The CFS wakeup code will only ever go through EAS / its fast path on
"regular" wakeups (i.e. not on forks or execs). These are currently gated
by a check against 'sd_flag', which would be SD_BALANCE_WAKE at wakeup.
However, we now have a flag that explicitly tells us whether a wakeup is a
"regular" one, so hinge those conditions on that flag instead.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
---
kernel/sched/fair.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f0b2b403bebb..30e8d357a24f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6355,7 +6355,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
sd_flag = SD_BALANCE_EXEC;
}
- if (sd_flag & SD_BALANCE_WAKE) {
+ if (wake_flags & WF_TTWU) {
record_wakee(p);
if (sched_energy_enabled()) {
@@ -6396,9 +6396,8 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
if (unlikely(sd)) {
/* Slow path */
new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag);
- } else if (sd_flag & SD_BALANCE_WAKE) { /* XXX always ? */
+ } else if (wake_flags & WF_TTWU) { /* XXX always ? */
/* Fast path */
-
new_cpu = select_idle_sibling(p, prev_cpu, new_cpu);
if (want_affine)
--
2.24.0
next prev parent reply other threads:[~2019-12-11 16:44 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 16:43 [RFC PATCH 0/7] sched: Streamline select_task_rq() & select_task_rq_fair() Valentin Schneider
2019-12-11 16:43 ` [RFC PATCH 1/7] sched: Add WF_TTWU, WF_EXEC wakeup flags Valentin Schneider
2019-12-11 16:43 ` [RFC PATCH 2/7] sched: Kill select_task_rq()'s sd_flag parameter Valentin Schneider
2019-12-11 16:43 ` [RFC PATCH 3/7] sched/fair: find_idlest_group(): Remove unused " Valentin Schneider
2019-12-11 16:43 ` Valentin Schneider [this message]
2019-12-11 16:53 ` [RFC PATCH 4/7] sched/fair: Dissociate wakeup decisions from SD flag value Valentin Schneider
2019-12-11 16:43 ` [RFC PATCH 5/7] sched/topology: Make {lowest/highest}_flag_domain() work with > 1 flags Valentin Schneider
2019-12-11 16:44 ` [RFC PATCH 6/7] sched/fair: Split select_task_rq_fair want_affine logic Valentin Schneider
2019-12-11 16:44 ` [RFC PATCH 7/7] sched/topology: Define and use shortcut pointers for wakeup sd_flag scan Valentin Schneider
2020-01-06 8:10 ` [RFC PATCH 0/7] sched: Streamline select_task_rq() & select_task_rq_fair() Peter Zijlstra
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