From: Josh Don <joshdon@google.com>
To: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
linux-kernel@vger.kernel.org, Josh Don <joshdon@google.com>
Subject: [PATCH v2] sched/fair: ignore cache hotness for SMT migration
Date: Tue, 4 Aug 2020 12:34:13 -0700 [thread overview]
Message-ID: <20200804193413.510651-1-joshdon@google.com> (raw)
In-Reply-To: <20200804105619.GE2657@hirez.programming.kicks-ass.net>
SMT siblings share caches, so cache hotness should be irrelevant for
cross-sibling migration.
Proposed-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Josh Don <joshdon@google.com>
---
kernel/sched/fair.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1a68a0536add..abdb54e2339f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7402,6 +7402,10 @@ static int task_hot(struct task_struct *p, struct lb_env *env)
if (unlikely(task_has_idle_policy(p)))
return 0;
+ /* SMT siblings share cache */
+ if (env->sd->flags & SD_SHARE_CPUCAPACITY)
+ return 0;
+
/*
* Buddy candidates are cache hot:
*/
--
2.28.0.163.g6104cc2f0b6-goog
next prev parent reply other threads:[~2020-08-04 19:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-04 0:06 [PATCH] sched/fair: ignore cache hotness for SMT migration Josh Don
2020-08-04 10:56 ` peterz
2020-08-04 19:24 ` Josh Don
2020-08-04 19:34 ` Josh Don [this message]
2020-08-10 6:14 ` [PATCH v2] " Srikar Dronamraju
2020-08-10 8:55 ` Valentin Schneider
2020-08-27 7:54 ` [tip: sched/core] sched/fair: Ignore " tip-bot2 for Josh Don
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