[PATCH v4 11/14] sched: Adapt sched tracepoints for RV task model
From: Gabriele Monaco <gmonaco@redhat.com>
Date: 2025-07-21 08:24:52
Also in:
lkml
Subsystem:
runtime verification (rv), scheduler, the rest, tracing · Maintainers:
Steven Rostedt, Gabriele Monaco, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds, Masami Hiramatsu
Add the following tracepoint:
* sched_set_need_resched(tsk, cpu, tif)
Called when a task is set the need resched [lazy] flag
Remove the unused ip parameter from sched_entry and sched_exit and alter
sched_entry to have a value of preempt consistent with the one used in
sched_switch.
Also adapt all monitors using sched_{entry,exit} to avoid breaking build.
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/).
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
include/linux/sched.h | 7 ++++++-
include/trace/events/sched.h | 12 ++++++++----
kernel/sched/core.c | 13 ++++++++++---
kernel/trace/rv/monitors/sco/sco.c | 4 ++--
kernel/trace/rv/monitors/scpd/scpd.c | 4 ++--
kernel/trace/rv/monitors/sncid/sncid.c | 4 ++--
kernel/trace/rv/monitors/snep/snep.c | 4 ++--
kernel/trace/rv/monitors/tss/tss.c | 4 ++--
8 files changed, 34 insertions(+), 18 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ba82d865df203..4dcde69996579 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h@@ -340,9 +340,11 @@ extern void io_schedule_finish(int token); extern long io_schedule_timeout(long timeout); extern void io_schedule(void); -/* wrapper function to trace from this header file */ +/* wrapper functions to trace from this header file */ DECLARE_TRACEPOINT(sched_set_state_tp); extern void __trace_set_current_state(int state_value); +DECLARE_TRACEPOINT(sched_set_need_resched_tp); +extern void __trace_set_need_resched(struct task_struct *curr, int tif); /** * struct prev_cputime - snapshot of system and user cputime
@@ -2026,6 +2028,9 @@ static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) static inline void set_tsk_need_resched(struct task_struct *tsk) { + if (tracepoint_enabled(sched_set_need_resched_tp) && + !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED)) + __trace_set_need_resched(tsk, TIF_NEED_RESCHED); set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); }
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 4e6b2910cec3f..c08893bde255d 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h@@ -882,18 +882,22 @@ DECLARE_TRACE(sched_compute_energy, TP_ARGS(p, dst_cpu, energy, max_util, busy_time)); DECLARE_TRACE(sched_entry, - TP_PROTO(bool preempt, unsigned long ip), - TP_ARGS(preempt, ip)); + TP_PROTO(bool preempt), + TP_ARGS(preempt)); DECLARE_TRACE(sched_exit, - TP_PROTO(bool is_switch, unsigned long ip), - TP_ARGS(is_switch, ip)); + TP_PROTO(bool is_switch), + TP_ARGS(is_switch)); DECLARE_TRACE_CONDITION(sched_set_state, TP_PROTO(struct task_struct *tsk, int state), TP_ARGS(tsk, state), TP_CONDITION(!!(tsk->__state) != !!state)); +DECLARE_TRACE(sched_set_need_resched, + TP_PROTO(struct task_struct *tsk, int cpu, int tif), + TP_ARGS(tsk, cpu, tif)); + #endif /* _TRACE_SCHED_H */ /* This part must be outside protection */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2343f5691c54e..63bcaade2569d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c@@ -1113,6 +1113,7 @@ static void __resched_curr(struct rq *rq, int tif) cpu = cpu_of(rq); + trace_sched_set_need_resched_tp(curr, cpu, tif); if (cpu == smp_processor_id()) { set_ti_thread_flag(cti, tif); if (tif == TIF_NEED_RESCHED)
@@ -1128,6 +1129,11 @@ static void __resched_curr(struct rq *rq, int tif) } } +void __trace_set_need_resched(struct task_struct *curr, int tif) +{ + trace_sched_set_need_resched_tp(curr, smp_processor_id(), tif); +} + void resched_curr(struct rq *rq) { __resched_curr(rq, TIF_NEED_RESCHED);
@@ -5279,7 +5285,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev) * 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); + trace_sched_exit_tp(true); preempt_enable(); if (current->set_child_tid)
@@ -6822,7 +6828,8 @@ static void __sched notrace __schedule(int sched_mode) struct rq *rq; int cpu; - trace_sched_entry_tp(preempt, CALLER_ADDR0); + /* Trace preemptions consistently with task switches */ + trace_sched_entry_tp(sched_mode == SM_PREEMPT); cpu = smp_processor_id(); rq = cpu_rq(cpu);
@@ -6961,7 +6968,7 @@ static void __sched notrace __schedule(int sched_mode) __balance_callbacks(rq); raw_spin_rq_unlock_irq(rq); } - trace_sched_exit_tp(is_switch, CALLER_ADDR0); + trace_sched_exit_tp(is_switch); } void __noreturn do_task_dead(void)
diff --git a/kernel/trace/rv/monitors/sco/sco.c b/kernel/trace/rv/monitors/sco/sco.c
index 66f4639d46ac4..04c36405e2e3d 100644
--- a/kernel/trace/rv/monitors/sco/sco.c
+++ b/kernel/trace/rv/monitors/sco/sco.c@@ -24,12 +24,12 @@ static void handle_sched_set_state(void *data, struct task_struct *tsk, int stat da_handle_start_event_sco(sched_set_state_sco); } -static void handle_schedule_entry(void *data, bool preempt, unsigned long ip) +static void handle_schedule_entry(void *data, bool preempt) { da_handle_event_sco(schedule_entry_sco); } -static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip) +static void handle_schedule_exit(void *data, bool is_switch) { da_handle_start_event_sco(schedule_exit_sco); }
diff --git a/kernel/trace/rv/monitors/scpd/scpd.c b/kernel/trace/rv/monitors/scpd/scpd.c
index 299703cd72b06..1e351ba52fee9 100644
--- a/kernel/trace/rv/monitors/scpd/scpd.c
+++ b/kernel/trace/rv/monitors/scpd/scpd.c@@ -30,12 +30,12 @@ static void handle_preempt_enable(void *data, unsigned long ip, unsigned long pa da_handle_start_event_scpd(preempt_enable_scpd); } -static void handle_schedule_entry(void *data, bool preempt, unsigned long ip) +static void handle_schedule_entry(void *data, bool preempt) { da_handle_event_scpd(schedule_entry_scpd); } -static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip) +static void handle_schedule_exit(void *data, bool is_switch) { da_handle_event_scpd(schedule_exit_scpd); }
diff --git a/kernel/trace/rv/monitors/sncid/sncid.c b/kernel/trace/rv/monitors/sncid/sncid.c
index 3e1ee715a0fbf..c8491f4263650 100644
--- a/kernel/trace/rv/monitors/sncid/sncid.c
+++ b/kernel/trace/rv/monitors/sncid/sncid.c@@ -30,12 +30,12 @@ static void handle_irq_enable(void *data, unsigned long ip, unsigned long parent da_handle_start_event_sncid(irq_enable_sncid); } -static void handle_schedule_entry(void *data, bool preempt, unsigned long ip) +static void handle_schedule_entry(void *data, bool preempt) { da_handle_start_event_sncid(schedule_entry_sncid); } -static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip) +static void handle_schedule_exit(void *data, bool is_switch) { da_handle_start_event_sncid(schedule_exit_sncid); }
diff --git a/kernel/trace/rv/monitors/snep/snep.c b/kernel/trace/rv/monitors/snep/snep.c
index 2adc3108d60c9..558950f524a52 100644
--- a/kernel/trace/rv/monitors/snep/snep.c
+++ b/kernel/trace/rv/monitors/snep/snep.c@@ -30,12 +30,12 @@ static void handle_preempt_enable(void *data, unsigned long ip, unsigned long pa da_handle_start_event_snep(preempt_enable_snep); } -static void handle_schedule_entry(void *data, bool preempt, unsigned long ip) +static void handle_schedule_entry(void *data, bool preempt) { da_handle_event_snep(schedule_entry_snep); } -static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip) +static void handle_schedule_exit(void *data, bool is_switch) { da_handle_start_event_snep(schedule_exit_snep); }
diff --git a/kernel/trace/rv/monitors/tss/tss.c b/kernel/trace/rv/monitors/tss/tss.c
index 0452fcd9edcfe..95ebd15131f52 100644
--- a/kernel/trace/rv/monitors/tss/tss.c
+++ b/kernel/trace/rv/monitors/tss/tss.c@@ -27,12 +27,12 @@ static void handle_sched_switch(void *data, bool preempt, da_handle_event_tss(sched_switch_tss); } -static void handle_schedule_entry(void *data, bool preempt, unsigned long ip) +static void handle_schedule_entry(void *data, bool preempt) { da_handle_event_tss(schedule_entry_tss); } -static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip) +static void handle_schedule_exit(void *data, bool is_switch) { da_handle_start_event_tss(schedule_exit_tss); }
--
2.50.1