lkml.org 
[lkml]   [2020]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 3/3] sched/fair: Dissociate wakeup decisions from SD flag value
Date
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 c02f7af0a925..4f9ff5d85ab2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6684,7 +6684,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
/* SD_flags and WF_flags share the first nibble */
int sd_flag = wake_flags & 0xF;

- if (sd_flag & SD_BALANCE_WAKE) {
+ if (wake_flags & WF_TTWU) {
record_wakee(p);

if (sched_energy_enabled()) {
@@ -6721,9 +6721,8 @@ 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)
--
2.27.0
\
 
 \ /
  Last update: 2020-11-02 19:48    [W:0.047 / U:0.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site