Anyway, ideally we'd do something like the below, except of course that it'll break userspace :-(
And that is why I loathe tracepoints. Also, I've not looked at the code difference and or performance implications. --- Subject: sched: Add enqueue information to trace_sched_wakeup() trace_sched_switch() shows task dequeues, trace_sched_wakeup() shows all wakeups, including those that do not enqueue (because the task is still enqueued). In order to easy matching dequeue to enqueue, add enqueue information to trace_sched_wakeup(). Replace the trace_sched_wakeup() success argument which is the try_to_wake_up() return value and always true (since we removed tracing the false path). Not-signed-off-by: Peter Zijlstra <[email protected]> --- include/trace/events/sched.h | 16 ++++++++-------- kernel/sched/core.c | 42 ++++++++++++++++++++++-------------------- kernel/sched/sched.h | 3 ++- 3 files changed, 32 insertions(+), 29 deletions(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 67e1bbf83695..5e5037f794f2 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -55,15 +55,15 @@ TRACE_EVENT(sched_kthread_stop_ret, */ DECLARE_EVENT_CLASS(sched_wakeup_template, - TP_PROTO(struct task_struct *p, int success), + TP_PROTO(struct task_struct *p, int enqueue), - TP_ARGS(__perf_task(p), success), + TP_ARGS(__perf_task(p), enqueue), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) __field( pid_t, pid ) __field( int, prio ) - __field( int, success ) + __field( int, enqueue ) __field( int, target_cpu ) ), @@ -71,24 +71,24 @@ DECLARE_EVENT_CLASS(sched_wakeup_template, memcpy(__entry->comm, p->comm, TASK_COMM_LEN); __entry->pid = p->pid; __entry->prio = p->prio; - __entry->success = success; + __entry->enqueue = enqueue; __entry->target_cpu = task_cpu(p); ), - TP_printk("comm=%s pid=%d prio=%d success=%d target_cpu=%03d", + TP_printk("comm=%s pid=%d prio=%d enqueue=%d target_cpu=%03d", __entry->comm, __entry->pid, __entry->prio, - __entry->success, __entry->target_cpu) + __entry->enqueue, __entry->target_cpu) ); DEFINE_EVENT(sched_wakeup_template, sched_wakeup, - TP_PROTO(struct task_struct *p, int success), + TP_PROTO(struct task_struct *p, int enqueue), TP_ARGS(p, success)); /* * Tracepoint for waking up a new task: */ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, - TP_PROTO(struct task_struct *p, int success), + TP_PROTO(struct task_struct *p, int enqueue), TP_ARGS(p, success)); #ifdef CREATE_TRACE_POINTS diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4ea7b3f1a087..e29b87748680 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1461,10 +1461,22 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) * Mark the task runnable and perform wakeup-preemption. */ static void -ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) +ttwu_do_wakeup(struct rq *rq, struct task_struct *p, + int wake_flags, en_flags) { + bool enqueue = wake_flags & WF_ENQUEUE; + + if (enqueue) { +#ifdef CONFIG_SMP + if (p->sched_contributes_to_load) + rq->nr_uninterruptible--; +#endif + + ttwu_activate(rq, p, en_flags); + } + check_preempt_curr(rq, p, wake_flags); - trace_sched_wakeup(p, true); + trace_sched_wakeup(p, enqueue); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -1485,18 +1497,6 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) #endif } -static void -ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) -{ -#ifdef CONFIG_SMP - if (p->sched_contributes_to_load) - rq->nr_uninterruptible--; -#endif - - ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); - ttwu_do_wakeup(rq, p, wake_flags); -} - /* * Called in case the task @p isn't fully descheduled from its runqueue, * in this case we must do a remote wakeup. Its a 'light' wakeup though, @@ -1512,7 +1512,7 @@ static int ttwu_remote(struct task_struct *p, int wake_flags) if (p->on_rq) { /* check_preempt_curr() may use rq clock */ update_rq_clock(rq); - ttwu_do_wakeup(rq, p, wake_flags); + ttwu_do_wakeup(rq, p, wake_flags, 0); ret = 1; } __task_rq_unlock(rq); @@ -1532,7 +1532,8 @@ static void sched_ttwu_pending(void) while (llist) { p = llist_entry(llist, struct task_struct, wake_entry); llist = llist_next(llist); - ttwu_do_activate(rq, p, 0); + ttwu_do_wakeup(rq, p, WF_ENQUEUE, + ENQUEUE_WAKEUP | ENQUEUE_WAKING); } raw_spin_unlock(&rq->lock); @@ -1604,7 +1605,7 @@ static void ttwu_queue(struct task_struct *p, int cpu) #endif raw_spin_lock(&rq->lock); - ttwu_do_activate(rq, p, 0); + ttwu_do_wakeup(rq, p, WF_ENQUEUE, ENQUEUE_WAKEUP | ENQUEUE_WAKING); raw_spin_unlock(&rq->lock); } @@ -1707,10 +1708,11 @@ static void try_to_wake_up_local(struct task_struct *p) if (!(p->state & TASK_NORMAL)) goto out; - if (!p->on_rq) - ttwu_activate(rq, p, ENQUEUE_WAKEUP); + if (p->on_rq) + ttwu_do_wakeup(rq, p, 0, 0); + else + ttwu_do_wakeup(rq, p, WF_ENQUEUE, ENQUEUE_WAKEUP); - ttwu_do_wakeup(rq, p, 0); ttwu_stat(p, smp_processor_id(), 0); out: raw_spin_unlock(&p->pi_lock); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b2cbe81308af..d865415ea1d2 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1026,7 +1026,8 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) */ #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ #define WF_FORK 0x02 /* child wakeup after fork */ -#define WF_MIGRATED 0x4 /* internal use, task got migrated */ +#define WF_MIGRATED 0x04 /* internal use, task got migrated */ +#define WF_ENQUEUE 0x08 /* * To aid in avoiding the subversion of "niceness" due to uneven distribution -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
