diff options
| author | Gabriele Monaco <gmonaco@redhat.com> | 2025-03-05 15:03:54 +0100 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-03-24 17:27:39 -0400 |
| commit | 26f80681a09b95fd64bcf33d02e258e78a30842b (patch) | |
| tree | e98095993f49a45b19669cfd0804c69de3804728 /kernel/sched/core.c | |
| parent | 41a4d2d3e3b6fe86bd54cc4c3b731378290a0d00 (diff) | |
sched: Add sched tracepoints for RV task model
Add the following tracepoints:
* sched_entry(bool preempt, ip)
Called while entering __schedule
* sched_exit(bool is_switch, ip)
Called while exiting __schedule
* sched_set_state(task, curr_state, state)
Called when a task changes its state (to and from running)
These tracepoints are useful to describe the Linux task model and are
adapted from the patches by Daniel Bristot de Oliveira
(https://bristot.me/linux-task-model/).
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9aecd914ac69..8294bf49b62b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -491,6 +491,16 @@ sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags) { } #endif /* CONFIG_SCHED_CORE */ +/* need a wrapper since we may need to trace from modules */ +EXPORT_TRACEPOINT_SYMBOL(sched_set_state_tp); + +/* Call via the helper macro trace_set_current_state. */ +void __trace_set_current_state(int state_value) +{ + trace_sched_set_state_tp(current, state_value); +} +EXPORT_SYMBOL(__trace_set_current_state); + /* * Serialization rules: * @@ -5307,6 +5317,12 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev) */ finish_task_switch(prev); + /* + * This is a special case: the newly created task has just + * switched the context for the first time. It is returning from + * schedule for the first time in this path. + */ + trace_sched_exit_tp(true, CALLER_ADDR0); preempt_enable(); if (current->set_child_tid) @@ -6650,12 +6666,15 @@ static void __sched notrace __schedule(int sched_mode) * as a preemption by schedule_debug() and RCU. */ bool preempt = sched_mode > SM_NONE; + bool is_switch = false; unsigned long *switch_count; unsigned long prev_state; struct rq_flags rf; struct rq *rq; int cpu; + trace_sched_entry_tp(preempt, CALLER_ADDR0); + cpu = smp_processor_id(); rq = cpu_rq(cpu); prev = rq->curr; @@ -6723,7 +6742,8 @@ picked: rq->last_seen_need_resched_ns = 0; #endif - if (likely(prev != next)) { + is_switch = prev != next; + if (likely(is_switch)) { rq->nr_switches++; /* * RCU users of rcu_dereference(rq->curr) may not see @@ -6768,6 +6788,7 @@ picked: __balance_callbacks(rq); raw_spin_rq_unlock_irq(rq); } + trace_sched_exit_tp(is_switch, CALLER_ADDR0); } void __noreturn do_task_dead(void) |