From: Mel Gorman <mgorman@techsingularity.net>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Phil Auld <pauld@redhat.com>, Hillf Danton <hdanton@sina.com>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 02/12] sched/numa: Trace when no candidate CPU was found on the preferred node
Date: Fri, 14 Feb 2020 08:13:14 +0000 [thread overview]
Message-ID: <20200214081324.26859-3-mgorman@techsingularity.net> (raw)
In-Reply-To: <20200214081324.26859-1-mgorman@techsingularity.net>
sched:sched_stick_numa is meant to fire when a task is unable to migrate
to the preferred node. The case where no candidate CPU could be found is
not traced which is an important gap. The tracepoint is not fired when
the task is not allowed to run on any CPU on the preferred node or the
task is already running on the target CPU but neither are interesting
corner cases.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
kernel/sched/fair.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ef3eb36ba5c4..d41a2b37694f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1848,8 +1848,10 @@ static int task_numa_migrate(struct task_struct *p)
}
/* No better CPU than the current one was found. */
- if (env.best_cpu == -1)
+ if (env.best_cpu == -1) {
+ trace_sched_stick_numa(p, env.src_cpu, -1);
return -EAGAIN;
+ }
best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
--
2.16.4
next prev parent reply other threads:[~2020-02-14 8:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-14 8:13 [PATCH 00/12] Reconcile NUMA balancing decisions with the load balancer v2 (resend) Mel Gorman
2020-02-14 8:13 ` [PATCH 01/12] sched/fair: Allow a per-CPU kthread waking a task to stack on the same CPU, to fix XFS performance regression Mel Gorman
2020-02-14 8:13 ` Mel Gorman [this message]
2020-02-14 8:13 ` [PATCH 03/12] sched/numa: Distinguish between the different task_numa_migrate failure cases Mel Gorman
2020-02-14 8:13 ` [PATCH 04/12] sched/fair: reorder enqueue/dequeue_task_fair path Mel Gorman
2020-02-14 8:13 ` [PATCH 05/12] sched/numa: replace runnable_load_avg by load_avg Mel Gorman
2020-02-14 8:13 ` [PATCH 06/12] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
2020-02-14 8:13 ` [PATCH 07/12] sched/fair: replace runnable load average by runnable average Mel Gorman
2020-02-14 8:17 ` [PATCH 08/12] sched/fair: Take into runnable_avg to classify group Mel Gorman
2020-02-14 8:17 ` [PATCH 09/12] sched/numa: Prefer using an idle cpu as a migration target instead of comparing tasks Mel Gorman
2020-02-14 8:17 ` [PATCH 10/12] sched/numa: Find an alternative idle CPU if the CPU is part of an active NUMA balance Mel Gorman
2020-02-14 8:18 ` [PATCH 11/12] sched/numa: Bias swapping tasks based on their preferred node Mel Gorman
2020-02-14 8:18 ` [PATCH 12/12] sched/numa: Stop an exhastive search if a reasonable swap candidate or idle CPU is found Mel Gorman
[not found] ` <20200214114746.10792-1-hdanton@sina.com>
2020-02-14 12:03 ` Mel Gorman
[not found] ` <20200214123229.20884-1-hdanton@sina.com>
2020-02-14 13:20 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2020-02-14 8:12 [PATCH 00/12] Reconcile NUMA balancing decisions with the load balancer v2 Mel Gorman
2020-02-14 8:12 ` [PATCH 02/12] sched/numa: Trace when no candidate CPU was found on the preferred node Mel Gorman
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