Messages in this thread Patch in this message | | | From | Valentin Schneider <> | Subject | [PATCH v2 2/3] sched/topology: Remove SD_BALANCE_WAKE on asymmetric capacity systems | Date | Fri, 24 Jan 2020 13:02:12 +0000 |
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From: Morten Rasmussen <morten.rasmussen@arm.com>
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@arm.com> [Changelog tweaks] Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- 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 dfb64c08a407a..00911884b7e7a 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; -- 2.24.0
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