Messages in this thread Patch in this message | | | From | Mel Gorman <> | 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 |
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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
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