The following commit has been merged into the sched/core branch of tip:
Commit-ID: 38c6e4963b509c47c33539534b84195558c0376d
Gitweb: https://git.kernel.org/tip/38c6e4963b509c47c33539534b84195558c0376d
Author: Morten Rasmussen <morten.rasmussen@xxxxxxx>
AuthorDate: Thu, 06 Feb 2020 19:19:55
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 11 Feb 2020 13:02:50 +01:00
sched/topology: Remove SD_BALANCE_WAKE on asymmetric capacity systems
SD_BALANCE_WAKE was previously added to lower sched_domain levels on
asymmetric CPU capacity systems by commit:
9ee1cda5ee25 ("sched/core: Enable SD_BALANCE_WAKE for asymmetric capacity systems")
to enable the use of find_idlest_cpu() and friends to find an appropriate
CPU for tasks.
That responsibility has now been shifted to select_idle_sibling() and
friends, and hence the flag can be removed. Note that this causes
asymmetric CPU capacity systems to no longer enter the slow wakeup path
(find_idlest_cpu()) on wakeups - only on execs and forks (which is aligned
with all other mainline topologies).
Signed-off-by: Morten Rasmussen <morten.rasmussen@xxxxxxx>
[Changelog tweaks]
Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Quentin Perret <qperret@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200206191957.12325-3-valentin.schneider@xxxxxxx
---
kernel/sched/topology.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index dfb64c0..0091188 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1374,18 +1374,9 @@ sd_init(struct sched_domain_topology_level *tl,
* Convert topological properties into behaviour.
*/
- if (sd->flags & SD_ASYM_CPUCAPACITY) {
- struct sched_domain *t = sd;
-
- /*
- * Don't attempt to spread across CPUs of different capacities.
- */
- if (sd->child)
- sd->child->flags &= ~SD_PREFER_SIBLING;
-
- for_each_lower_domain(t)
- t->flags |= SD_BALANCE_WAKE;
- }
+ /* Don't attempt to spread across CPUs of different capacities. */
+ if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child)
+ sd->child->flags &= ~SD_PREFER_SIBLING;
if (sd->flags & SD_SHARE_CPUCAPACITY) {
sd->imbalance_pct = 110;
|