superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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>
pull/1188/head
Gabriele Monaco 2025-03-05 15:03:54 +01:00 committed by Steven Rostedt (Google)
parent 41a4d2d3e3
commit 26f80681a0
5 changed files with 53 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/rv.h
View File

@ -7,7 +7,7 @@
#ifndef _LINUX_RV_H
#define _LINUX_RV_H
#define MAX_DA_NAME_LEN 24
#define MAX_DA_NAME_LEN 32
#ifdef CONFIG_RV
/*

16
include/linux/sched.h
View File

@ -46,6 +46,7 @@
#include <linux/rv.h>
#include <linux/livepatch_sched.h>
#include <linux/uidgid_types.h>
#include <linux/tracepoint-defs.h>
#include <asm/kmap_size.h>
/* task_struct member predeclarations (sorted alphabetically): */
@ -186,6 +187,12 @@ struct user_event_mm;
# define debug_rtlock_wait_restore_state() do { } while (0)
#endif
#define trace_set_current_state(state_value) \
do { \
if (tracepoint_enabled(sched_set_state_tp)) \
__trace_set_current_state(state_value); \
} while (0)
/*
* set_current_state() includes a barrier so that the write of current->__state
* is correctly serialised wrt the caller's subsequent test of whether to
@ -226,12 +233,14 @@ struct user_event_mm;
#define __set_current_state(state_value) \
do { \
debug_normal_state_change((state_value)); \
trace_set_current_state(state_value); \
WRITE_ONCE(current->__state, (state_value)); \
} while (0)
#define set_current_state(state_value) \
do { \
debug_normal_state_change((state_value)); \
trace_set_current_state(state_value); \
smp_store_mb(current->__state, (state_value)); \
} while (0)
@ -247,6 +256,7 @@ struct user_event_mm;
\
raw_spin_lock_irqsave(&current->pi_lock, flags); \
debug_special_state_change((state_value)); \
trace_set_current_state(state_value); \
WRITE_ONCE(current->__state, (state_value)); \
raw_spin_unlock_irqrestore(&current->pi_lock, flags); \
} while (0)
@ -282,6 +292,7 @@ struct user_event_mm;
raw_spin_lock(&current->pi_lock); \
current->saved_state = current->__state; \
debug_rtlock_wait_set_state(); \
trace_set_current_state(TASK_RTLOCK_WAIT); \
WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
raw_spin_unlock(&current->pi_lock); \
} while (0);
@ -291,6 +302,7 @@ struct user_event_mm;
lockdep_assert_irqs_disabled(); \
raw_spin_lock(&current->pi_lock); \
debug_rtlock_wait_restore_state(); \
trace_set_current_state(current->saved_state); \
WRITE_ONCE(current->__state, current->saved_state); \
current->saved_state = TASK_RUNNING; \
raw_spin_unlock(&current->pi_lock); \
@ -327,6 +339,10 @@ 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 */
DECLARE_TRACEPOINT(sched_set_state_tp);
extern void __trace_set_current_state(int state_value);
/**
* struct prev_cputime - snapshot of system and user cputime
* @utime: time spent in user mode

13
include/trace/events/sched.h
View File

@ -824,6 +824,19 @@ DECLARE_TRACE(sched_compute_energy_tp,
unsigned long max_util, unsigned long busy_time),
TP_ARGS(p, dst_cpu, energy, max_util, busy_time));
DECLARE_TRACE(sched_entry_tp,
TP_PROTO(bool preempt, unsigned long ip),
TP_ARGS(preempt, ip));
DECLARE_TRACE(sched_exit_tp,
TP_PROTO(bool is_switch, unsigned long ip),
TP_ARGS(is_switch, ip));
DECLARE_TRACE_CONDITION(sched_set_state_tp,
TP_PROTO(struct task_struct *tsk, int state),
TP_ARGS(tsk, state),
TP_CONDITION(!!(tsk->__state) != !!state));
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */

23
kernel/sched/core.c
View File

@ -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)

2
tools/verification/rv/include/rv.h
View File

@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#define MAX_DESCRIPTION 1024
#define MAX_DA_NAME_LEN 24
#define MAX_DA_NAME_LEN 32
struct monitor {
char name[MAX_DA_NAME_LEN];