From nobody Sun Dec 14 06:20:54 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 C425A27603A for ; Tue, 15 Jul 2025 07:16:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752563772; cv=none; b=t+B1B7m6bH8MFrMcEe0ajDruwrVLt3HZavUvk5jTrMawFNNF+gq4WralHp3ExJLi3UJegLQo11RK4NyNTSGUV39ix1VE5QrbSybqOSsBjRtpXjzis47udRWjnuaebw7RBjQfN2epbRSjIo1eNHKIhL+3w1xAkPyl5knuRwZaEcE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752563772; c=relaxed/simple; bh=wFdF7EpXBYFWK9Jbm8c0lN86C3/98hbYMMGEfzZbW9s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PoC84Ue35Wven58Fe4a1xCYN2aaxIcMoZNVU2xNC3IzFYgylS+ZYumY80D4oYk5o4he3bBOg3PbwOz/oSooK+e+bzuxxdSphk3FcSwcymS9ZyniX7xMSwoultClNijLCbmE84xcmjlWilUJ4g8BGi4n17J3k5pJzrehFf7QIE1w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fr0UuRKN; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fr0UuRKN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752563769; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PYlgmcKzwEhoS0a9BGFylsAetkBhqQKG1+nbvaKZxSA=; b=fr0UuRKNybfTGkUOYMjUnDXWZ1Bb6eoJkW6CYGhielbepk8a5TMfDooUAqo3ccTzffdR7E hMITZuPKrOZiz7bANg/3SB0Jqjy0Dv2aE59xy566dG3kKSWXx5MoW6W8AT9g6ZlY28Y3us xoVC/kkaT2MgvWwJE0p5E4xLssPtPo8= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-641-MvhcTSVKNjKHJXiaq0bkJQ-1; Tue, 15 Jul 2025 03:16:08 -0400 X-MC-Unique: MvhcTSVKNjKHJXiaq0bkJQ-1 X-Mimecast-MFC-AGG-ID: MvhcTSVKNjKHJXiaq0bkJQ_1752563767 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EA9C11801210; Tue, 15 Jul 2025 07:16:06 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.com (unknown [10.45.224.115]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id AF544180045B; Tue, 15 Jul 2025 07:16:01 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Steven Rostedt , Masami Hiramatsu , linux-trace-kernel@vger.kernel.org Cc: Gabriele Monaco , Nam Cao , Tomas Glozar , Juri Lelli , Clark Williams , John Kacur Subject: [PATCH v3 12/17] sched: Adapt sched tracepoints for RV task model Date: Tue, 15 Jul 2025 09:14:29 +0200 Message-ID: <20250715071434.22508-13-gmonaco@redhat.com> In-Reply-To: <20250715071434.22508-1-gmonaco@redhat.com> References: <20250715071434.22508-1-gmonaco@redhat.com> 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 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Add the following tracepoints: * sched_set_need_resched(tsk, cpu, tif) Called when a task is set the need resched [lazy] flag * sched_switch_vain(preempt, tsk, tsk_state) Called when a task is selected again during __schedule i.e. prev =3D=3D next =3D=3D tsk : no real context switch Add new parameter to sched_set_state to identify whether the state change was due to an explicit call or a signal pending while scheduling. We now also trace from try_to_block_task in case a signal was pending and the task is set to runnable. Also adapt all monitors using sched_set_state 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 --- include/linux/sched.h | 7 ++++++- include/trace/events/sched.h | 17 +++++++++++++++-- kernel/sched/core.c | 10 +++++++++- kernel/trace/rv/monitors/sco/sco.c | 3 ++- kernel/trace/rv/monitors/sleep/sleep.c | 3 ++- kernel/trace/rv/monitors/snroc/snroc.c | 3 ++- 6 files changed, 36 insertions(+), 7 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 7bce4c7ae3b4f..19ab4597c97d3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -339,9 +339,11 @@ 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 */ +/* 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); =20 /** * struct prev_cputime - snapshot of system and user cputime @@ -2059,6 +2061,9 @@ static inline int test_tsk_thread_flag(struct task_st= ruct *tsk, int flag) =20 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); } =20 diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 4e6b2910cec3f..c9dec6d38ad2d 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -889,11 +889,24 @@ DECLARE_TRACE(sched_exit, TP_PROTO(bool is_switch, unsigned long ip), TP_ARGS(is_switch, ip)); =20 +/* + * Tracepoint called when setting the state of a task; + * this tracepoint is guaranteed to be called from the waking context of t= he + * task setting the state. + */ DECLARE_TRACE_CONDITION(sched_set_state, - TP_PROTO(struct task_struct *tsk, int state), - TP_ARGS(tsk, state), + TP_PROTO(struct task_struct *tsk, int state, bool from_signal), + TP_ARGS(tsk, state, from_signal), TP_CONDITION(!!(tsk->__state) !=3D !!state)); =20 +DECLARE_TRACE(sched_set_need_resched, + TP_PROTO(struct task_struct *tsk, int cpu, int tif), + TP_ARGS(tsk, cpu, tif)); + +DECLARE_TRACE(sched_switch_vain, + TP_PROTO(bool preempt, struct task_struct *tsk, unsigned int prev_state), + TP_ARGS(preempt, tsk, prev_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 81c6df746df17..6cb70e6f7fa17 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -495,7 +495,7 @@ 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); + trace_sched_set_state_tp(current, state_value, false); } EXPORT_SYMBOL(__trace_set_current_state); =20 @@ -1110,6 +1110,7 @@ static void __resched_curr(struct rq *rq, int tif) =20 cpu =3D cpu_of(rq); =20 + trace_sched_set_need_resched_tp(curr, cpu, tif); if (cpu =3D=3D smp_processor_id()) { set_ti_thread_flag(cti, tif); if (tif =3D=3D TIF_NEED_RESCHED) @@ -1125,6 +1126,11 @@ static void __resched_curr(struct rq *rq, int tif) } } =20 +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); @@ -6592,6 +6598,7 @@ static bool try_to_block_task(struct rq *rq, struct t= ask_struct *p, int flags =3D DEQUEUE_NOCLOCK; =20 if (signal_pending_state(task_state, p)) { + trace_sched_set_state_tp(p, TASK_RUNNING, true); WRITE_ONCE(p->__state, TASK_RUNNING); *task_state_p =3D TASK_RUNNING; return false; @@ -6786,6 +6793,7 @@ static void __sched notrace __schedule(int sched_mode) rq =3D context_switch(rq, prev, next, &rf); } else { rq_unpin_lock(rq, &rf); + trace_sched_switch_vain_tp(preempt, prev, prev_state); __balance_callbacks(rq); raw_spin_rq_unlock_irq(rq); } diff --git a/kernel/trace/rv/monitors/sco/sco.c b/kernel/trace/rv/monitors/= sco/sco.c index 66f4639d46ac4..c9206aa12c319 100644 --- a/kernel/trace/rv/monitors/sco/sco.c +++ b/kernel/trace/rv/monitors/sco/sco.c @@ -19,7 +19,8 @@ static struct rv_monitor rv_sco; DECLARE_DA_MON_PER_CPU(sco, unsigned char); =20 -static void handle_sched_set_state(void *data, struct task_struct *tsk, in= t state) +static void handle_sched_set_state(void *data, struct task_struct *tsk, + int state, bool from_signal) { da_handle_start_event_sco(sched_set_state_sco); } diff --git a/kernel/trace/rv/monitors/sleep/sleep.c b/kernel/trace/rv/monit= ors/sleep/sleep.c index eea447b069071..5103a98818c53 100644 --- a/kernel/trace/rv/monitors/sleep/sleep.c +++ b/kernel/trace/rv/monitors/sleep/sleep.c @@ -82,7 +82,8 @@ static void ltl_atoms_init(struct task_struct *task, stru= ct ltl_monitor *mon, bo =20 } =20 -static void handle_sched_set_state(void *data, struct task_struct *task, i= nt state) +static void handle_sched_set_state(void *data, struct task_struct *task, + int state, bool from_signal) { if (state & TASK_INTERRUPTIBLE) ltl_atom_pulse(task, LTL_SLEEP, true); diff --git a/kernel/trace/rv/monitors/snroc/snroc.c b/kernel/trace/rv/monit= ors/snroc/snroc.c index 540e686e699f4..2651f589d1554 100644 --- a/kernel/trace/rv/monitors/snroc/snroc.c +++ b/kernel/trace/rv/monitors/snroc/snroc.c @@ -19,7 +19,8 @@ static struct rv_monitor rv_snroc; DECLARE_DA_MON_PER_TASK(snroc, unsigned char); =20 -static void handle_sched_set_state(void *data, struct task_struct *tsk, in= t state) +static void handle_sched_set_state(void *data, struct task_struct *tsk, + int state, bool from_signal) { da_handle_event_snroc(tsk, sched_set_state_snroc); } --=20 2.50.1