From 070fe6fcb7291170e36ec8b8b9ca9709b1222f00 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 23 Oct 2020 12:12:15 +0200 Subject: [PATCH 018/296] sched: Add migrate_disable() tracepoints Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.35-rt39.tar.xz XXX write a tracer: - 'migirate_disable() -> migrate_enable()' time in task_sched_runtime() - 'migrate_pull -> sched-in' time in task_sched_runtime() The first will give worst case for the second, which is the actual interference experienced by the task to due migration constraints of migrate_disable(). Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Sebastian Andrzej Siewior --- include/trace/events/sched.h | 12 ++++++++++++ kernel/sched/core.c | 4 ++++ kernel/sched/deadline.c | 1 + kernel/sched/rt.c | 8 +++++++- 4 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index c96a4337afe6..e48f584abf5f 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -650,6 +650,18 @@ DECLARE_TRACE(sched_update_nr_running_tp, TP_PROTO(struct rq *rq, int change), TP_ARGS(rq, change)); +DECLARE_TRACE(sched_migrate_disable_tp, + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); + +DECLARE_TRACE(sched_migrate_enable_tp, + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); + +DECLARE_TRACE(sched_migrate_pull_tp, + TP_PROTO(struct task_struct *p), + TP_ARGS(p)); + #endif /* _TRACE_SCHED_H */ /* This part must be outside protection */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index dd9c1fed70a6..5cad6f589ffd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1726,6 +1726,8 @@ void migrate_disable(void) return; } + trace_sched_migrate_disable_tp(p); + preempt_disable(); this_rq()->nr_pinned++; p->migration_disabled = 1; @@ -1758,6 +1760,8 @@ void migrate_enable(void) p->migration_disabled = 0; this_rq()->nr_pinned--; preempt_enable(); + + trace_sched_migrate_enable_tp(p); } EXPORT_SYMBOL_GPL(migrate_enable); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 8d615aacaafc..56faef8c9238 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2278,6 +2278,7 @@ static void pull_dl_task(struct rq *this_rq) goto skip; if (is_migration_disabled(p)) { + trace_sched_migrate_pull_tp(p); push_task = get_push_task(src_rq); } else { deactivate_task(src_rq, p, 0); diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index c592e47cafed..1ed7e3dfee9e 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1877,7 +1877,12 @@ static int push_rt_task(struct rq *rq, bool pull) struct task_struct *push_task = NULL; int cpu; - if (!pull || rq->push_busy) + if (!pull) + return 0; + + trace_sched_migrate_pull_tp(next_task); + + if (rq->push_busy) return 0; cpu = find_lowest_rq(rq->curr); @@ -2223,6 +2228,7 @@ static void pull_rt_task(struct rq *this_rq) goto skip; if (is_migration_disabled(p)) { + trace_sched_migrate_pull_tp(p); push_task = get_push_task(src_rq); } else { deactivate_task(src_rq, p, 0); -- 2.30.2