From patchwork Tue Feb 11 07:46:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriele Monaco X-Patchwork-Id: 13969945 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 76C091EE7AD for ; Tue, 11 Feb 2025 07:46:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739260012; cv=none; b=C3BC38t19k57Jzwh22CCB0L9QWUCI7i6g9W/w2sRbUeMGiNGbW7LJDzBZ6w0ygsPnMAaFek5XVDUo+pjF61yZkOtQBGipc+1FHY0VF/IMgiCLeeBZ/KTe1i8WXdCwzu6Ec/HGWdheqzMQfFK4XH12AOo+wOv5ZtXJ4E/EgwzVaU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739260012; c=relaxed/simple; bh=Dcm7FZdk9PPahCWA8S3XNCpQHOsO5jQdSBQsW9eKzxs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rClqc3VY2srApPDJEivLte9sdNFr0arXVgcfC9ei+6s3tt54+xsscysT5hb6G4McVaN/sgFgdjzY/gpzVItHniYx0QW/gwKk2T/c7pH1qgjYge7pTGBan758Q+FeH5r1a9RmCJcZDCuFlP011ymhg4Zrz+5q9qpG+bXz1dJfaDc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=Yzl44PDc; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="Yzl44PDc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739260009; 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=IqOfBOBvtTpUrz+HtMQBkctVf4fqKNhadITBcAOuLQ4=; b=Yzl44PDcvA4mxlAC7AE6Wc5nyPlmzLILN6SH6Aepr3419+A3iDtfGo9ag7VewPOu5QyYyU yNahxGrrRMUk0tjZ25RLqj6Kp+z3LPvXhhpmfMfZ9vjHO4EsL3hpwKjcTjDEOcTCuNEmiY haYxB524ylMA+U15xl1hNovJMn3HvnU= Received: from mx-prod-mc-08.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-416-VdS5DIbLM3q8iYaMYmvt7A-1; Tue, 11 Feb 2025 02:46:45 -0500 X-MC-Unique: VdS5DIbLM3q8iYaMYmvt7A-1 X-Mimecast-MFC-AGG-ID: VdS5DIbLM3q8iYaMYmvt7A Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5EBC2180087D; Tue, 11 Feb 2025 07:46:44 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.com (unknown [10.45.224.45]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id BA4B5195608D; Tue, 11 Feb 2025 07:46:40 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Steven Rostedt , Ingo Molnar , Peter Zijlstra , Masami Hiramatsu , linux-trace-kernel@vger.kernel.org Cc: Gabriele Monaco , Juri Lelli Subject: [PATCH v1 03/11] sched: Add sched tracepoints for RV task model Date: Tue, 11 Feb 2025 08:46:10 +0100 Message-ID: <20250211074622.58590-4-gmonaco@redhat.com> In-Reply-To: <20250211074622.58590-1-gmonaco@redhat.com> References: <20250211074622.58590-1-gmonaco@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 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/). Signed-off-by: Gabriele Monaco --- include/linux/rv.h | 2 +- include/linux/sched.h | 16 ++++++++++++++++ include/trace/events/sched.h | 13 +++++++++++++ kernel/sched/core.c | 22 +++++++++++++++++++++- tools/verification/rv/include/rv.h | 2 +- 5 files changed, 52 insertions(+), 3 deletions(-) diff --git a/include/linux/rv.h b/include/linux/rv.h index 8883b41d88ec4..55d458be53a4c 100644 --- a/include/linux/rv.h +++ b/include/linux/rv.h @@ -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 /* diff --git a/include/linux/sched.h b/include/linux/sched.h index 9632e3318e0d6..9ff0658095240 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -46,6 +46,7 @@ #include #include #include +#include #include /* 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)) \ + do_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(¤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 = 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(TASK_RUNNING); \ WRITE_ONCE(current->__state, current->saved_state); \ current->saved_state = 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); +/* wrapper function to trace from this header file */ +DECLARE_TRACEPOINT(sched_set_state_tp); +extern void do_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 9ea4c404bd4ef..cc3be04fe9986 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)); +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 curr_state, int state), + TP_ARGS(tsk, curr_state, state), + TP_CONDITION(!!curr_state != !!state)); + #endif /* _TRACE_SCHED_H */ /* This part must be outside protection */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 165c90ba64ea9..9e33728bb57e8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -491,6 +491,15 @@ 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); + +void do_trace_set_current_state(int state_value) +{ + trace_sched_set_state_tp(current, current->__state, state_value); +} +EXPORT_SYMBOL(do_trace_set_current_state); + /* * Serialization rules: * @@ -5306,6 +5315,12 @@ 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 fist 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) @@ -6649,12 +6664,15 @@ 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; @@ -6722,7 +6740,8 @@ static void __sched notrace __schedule(int sched_mode) 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 @@ -6767,6 +6786,7 @@ 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); } void __noreturn do_task_dead(void) diff --git a/tools/verification/rv/include/rv.h b/tools/verification/rv/include/rv.h index 770fd6da36107..0cab1037a98f7 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 #define MAX_DESCRIPTION 1024 -#define MAX_DA_NAME_LEN 24 +#define MAX_DA_NAME_LEN 32 struct monitor { char name[MAX_DA_NAME_LEN];