From nobody Thu Dec 18 08:37:57 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 341E51EE7AD for ; Tue, 25 Mar 2025 14:34:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742913258; cv=none; b=iq2DrHdoF4qHMjnXQfndkn3rCF/KU59G6l1cWj8Tr3j9nDzfbqoPaFv8EiuRLSe0VsFX7MQVj9ipLTjpg2VW5NMuH/kyAIpSi8XpTr5Hzk59dVNImDdRRgJyO0C3ZqgvdC7J+uHxY104ca1Fr+N5bsv3DySB+E5qnuhbJhduBqA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742913258; c=relaxed/simple; bh=Dv60DLAilPAXovwEDzTaAb5UeRlBO5uxNec0pmFygi0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=bTu/I11ngxjt3dWeISsv12+Dl1wcGTMUQHRT0RXvD26jVlDSbCiR4899oIzxiQc2+L0udUg7zE+9FuDzF3Ktc+VHHyPdzRYc/K0XGous7I3N3HngBGi4uOiPWtFaHjzUcZ144e5ZpyJ47Va99C26+Uj9Q3/J3zHatcXUnAsw4uQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B50AFC4CEED; Tue, 25 Mar 2025 14:34:17 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1tx5Ms-00000002Oyv-0PRb; Tue, 25 Mar 2025 10:35:02 -0400 Message-ID: <20250325143501.952352927@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 25 Mar 2025 10:34:37 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Tomas Glozar , John Kacur , Ingo Molnar , Masami Hiramatsu , Juri Lelli , Gabriele Monaco , "Peter Zijlstra (Intel)" Subject: [for-next][PATCH 1/9] sched: Add sched tracepoints for RV task model References: <20250325143436.168114339@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Gabriele Monaco 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 Cc: Masami Hiramatsu Cc: Juri Lelli Link: https://lore.kernel.org/20250305140406.350227-2-gmonaco@redhat.com Signed-off-by: Gabriele Monaco Acked-by: Peter Zijlstra (Intel) Signed-off-by: Steven Rostedt (Google) --- include/linux/rv.h | 2 +- include/linux/sched.h | 16 ++++++++++++++++ include/trace/events/sched.h | 13 +++++++++++++ kernel/sched/core.c | 23 ++++++++++++++++++++++- tools/verification/rv/include/rv.h | 2 +- 5 files changed, 53 insertions(+), 3 deletions(-) diff --git a/include/linux/rv.h b/include/linux/rv.h index 8883b41d88ec..55d458be53a4 100644 --- a/include/linux/rv.h +++ b/include/linux/rv.h @@ -7,7 +7,7 @@ #ifndef _LINUX_RV_H #define _LINUX_RV_H =20 -#define MAX_DA_NAME_LEN 24 +#define MAX_DA_NAME_LEN 32 =20 #ifdef CONFIG_RV /* diff --git a/include/linux/sched.h b/include/linux/sched.h index 9632e3318e0d..45a61a0b9790 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -46,6 +46,7 @@ #include #include #include +#include #include =20 /* task_struct member predeclarations (sorted alphabetically): */ @@ -186,6 +187,12 @@ struct user_event_mm; # define debug_rtlock_wait_restore_state() do { } while (0) #endif =20 +#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) =20 #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) =20 @@ -247,6 +256,7 @@ struct user_event_mm; \ raw_spin_lock_irqsave(¤t->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(¤t->pi_lock, flags); \ } while (0) @@ -282,6 +292,7 @@ struct user_event_mm; raw_spin_lock(¤t->pi_lock); \ current->saved_state =3D current->__state; \ debug_rtlock_wait_set_state(); \ + trace_set_current_state(TASK_RTLOCK_WAIT); \ WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ raw_spin_unlock(¤t->pi_lock); \ } while (0); @@ -291,6 +302,7 @@ struct user_event_mm; lockdep_assert_irqs_disabled(); \ raw_spin_lock(¤t->pi_lock); \ debug_rtlock_wait_restore_state(); \ + trace_set_current_state(current->saved_state); \ WRITE_ONCE(current->__state, current->saved_state); \ current->saved_state =3D TASK_RUNNING; \ raw_spin_unlock(¤t->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); =20 +/* 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 diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 9ea4c404bd4e..90545125c903 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -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)); =20 +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) !=3D !!state)); + #endif /* _TRACE_SCHED_H */ =20 /* This part must be outside protection */ 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) { } =20 #endif /* CONFIG_SCHED_CORE */ =20 +/* 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) */ =20 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(); =20 if (current->set_child_tid) @@ -6650,12 +6666,15 @@ static void __sched notrace __schedule(int sched_mo= de) * as a preemption by schedule_debug() and RCU. */ bool preempt =3D sched_mode > SM_NONE; + bool is_switch =3D false; unsigned long *switch_count; unsigned long prev_state; struct rq_flags rf; struct rq *rq; int cpu; =20 + trace_sched_entry_tp(preempt, CALLER_ADDR0); + cpu =3D smp_processor_id(); rq =3D cpu_rq(cpu); prev =3D rq->curr; @@ -6723,7 +6742,8 @@ static void __sched notrace __schedule(int sched_mode) rq->last_seen_need_resched_ns =3D 0; #endif =20 - if (likely(prev !=3D next)) { + is_switch =3D prev !=3D next; + if (likely(is_switch)) { rq->nr_switches++; /* * RCU users of rcu_dereference(rq->curr) may not see @@ -6768,6 +6788,7 @@ 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); } =20 void __noreturn do_task_dead(void) diff --git a/tools/verification/rv/include/rv.h b/tools/verification/rv/inc= lude/rv.h index 770fd6da3610..0cab1037a98f 100644 --- a/tools/verification/rv/include/rv.h +++ b/tools/verification/rv/include/rv.h @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 =20 #define MAX_DESCRIPTION 1024 -#define MAX_DA_NAME_LEN 24 +#define MAX_DA_NAME_LEN 32 =20 struct monitor { char name[MAX_DA_NAME_LEN]; --=20 2.47.2