From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86BC2C05027 for ; Thu, 2 Feb 2023 18:41:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229915AbjBBSlq (ORCPT ); Thu, 2 Feb 2023 13:41:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232897AbjBBSlj (ORCPT ); Thu, 2 Feb 2023 13:41:39 -0500 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FD675454F for ; Thu, 2 Feb 2023 10:40:58 -0800 (PST) Received: by mail-pj1-x104a.google.com with SMTP id pv1-20020a17090b3c8100b0022c1ab71110so3267494pjb.7 for ; Thu, 02 Feb 2023 10:40:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=eq0ulXMOCofqygUrvWm3TIivHTQgIXHPYH8AiMJK0m4=; b=bDN/F5+92U9ElOjd1SYVToTojhMiCQYGQISkGNS8PM1648rxpmyQ3QKgjpbuD7I6NN qgetR+X51HYf/Go5JRnPXrz/iM74aLFsI8+br9BFEftVOgmDNsLHwaB1qw0+VMzC20A8 HcuOaUGFY1AxKT4gJhCOEpLXLd0wWSBkjJzCwQ7RCoA7mJidt+kpy9/MlXB3fc8bK+yj cfMq7T27ZekbeZSzpoVUUL5feMw7KQLg5NJp/9e/ehTgzTMM1ygK+zTnWoYtRJZ0SUbF Iyjst+/jW7a/xd+sXjMmitt5XKMM75YACl+e0+JckvsO187i7FaslLnv8YG5Y1nNWjvu Ndtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=eq0ulXMOCofqygUrvWm3TIivHTQgIXHPYH8AiMJK0m4=; b=IKaKcwy0WAlNB+49TvKctWle3o5XOynXojA+jux+49DdmgYDfVaVhJKUT62rgK9zt4 SV6ShfsCFFkPZW314i8TVOquwxy2XbFjuRfVCFxXF6BeRwOt+kK+RMlWqibY4kiTQhu5 PY9xYNkkS6udjbqG5SrGt1fi632amtdpIEYCNpcMoykG92Z1km1A8eCBEOev5MPioe2E 4WrbGKT+Gmc4N8pBeYaZLbWx5JCvrZP2DixZiSWTojFe5Z46dB3+YA2Ka2sMX6P7tJ5T aZHXIjs8+haImowf/PqmdHrKFa4iU93a3mFXHTzrIojgUXldj+A98NUMkUZ+jAIyxg/d f/iw== X-Gm-Message-State: AO0yUKUbDxJozBzHOy/o43b3oWYk1ufgGOGBmJA6oanL/Y25idyXjlAQ 3B92nns+iAH8RcACF43TyNlwZwtQNNazwmON8q0VxVa+Mh7BubJPBNuGRbxe9aQE5S1OPfJLKgR ihQYMBNZ6ubqmRcq4ylqk85ixhRxrG+qe+oQqn0pJpyN/ieHLnn+GWpg268gS2cGqpFVv/t8= X-Google-Smtp-Source: AK7set/0YEW8im9qYiikDlyp4cuSXMahQOw9o82iZ/sT06lXQeZm+uxoXQpRb9CiyBeI6aNrNQUdmu7G8zqO X-Received: from jstultz-noogler2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:600]) (user=jstultz job=sendgmr) by 2002:a63:475f:0:b0:4da:d745:98da with SMTP id w31-20020a63475f000000b004dad74598damr1241724pgk.46.1675363222206; Thu, 02 Feb 2023 10:40:22 -0800 (PST) Date: Thu, 2 Feb 2023 18:40:18 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Message-ID: <20230202184018.2576687-1-jstultz@google.com> Subject: [RESEND][PATCH v3] trace: Add trace points for tasklet entry/exit From: John Stultz To: LKML Cc: Lingutla Chandrasekhar , Steven Rostedt , Masami Hiramatsu , Thomas Gleixner , "Paul E. McKenney" , kernel-team@android.com, "J . Avila" , John Stultz Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lingutla Chandrasekhar Tasklets are supposed to finish their work quickly and should not block the current running process, but it is not guaranteed that. Currently softirq_entry/exit can be used to know total tasklets execution time, but not helpful to track individual tasklet's execution time. With that we can't find any culprit tasklet function, which is taking more time. Add tasklet_entry/exit trace point support to track individual tasklet execution. Trivial usage example: # echo 1 > /sys/kernel/debug/tracing/events/irq/tasklet_entry/enable # echo 1 > /sys/kernel/debug/tracing/events/irq/tasklet_exit/enable # cat /sys/kernel/debug/tracing/trace # tracer: nop # # entries-in-buffer/entries-written: 4/4 #P:4 # # _-----=> irqs-off/BH-disabled # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / _-=> migrate-disable # |||| / delay # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | -0 [003] ..s1. 314.011428: tasklet_entry: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func -0 [003] ..s1. 314.011432: tasklet_exit: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func -0 [003] ..s1. 314.017369: tasklet_entry: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func -0 [003] ..s1. 314.017371: tasklet_exit: tasklet=0xffffa01ef8db2740 function=tcp_tasklet_func This patch has been carried in the Android tree for awhile so I wanted to submit it for review upstream. Feedback would be appreciated! Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Thomas Gleixner Cc: "Paul E. McKenney" Cc: kernel-team@android.com Reviewed-by: Steven Rostedt (Google) Signed-off-by: Lingutla Chandrasekhar [elavila: Port to android-mainline] Signed-off-by: J. Avila [jstultz: Rebased to upstream, cut unused trace points, added comments for the tracepoints, reworded commit] Signed-off-by: John Stultz --- v2: * Added tasklet pointer to the trace event as suggested by Steven v3: * Minor tweak to commit to show usage and output example --- include/trace/events/irq.h | 47 ++++++++++++++++++++++++++++++++++++++ kernel/softirq.c | 9 ++++++-- 2 files changed, 54 insertions(+), 2 deletions(-) diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h index eeceafaaea4c..a07b4607b663 100644 --- a/include/trace/events/irq.h +++ b/include/trace/events/irq.h @@ -160,6 +160,53 @@ DEFINE_EVENT(softirq, softirq_raise, TP_ARGS(vec_nr) ); +DECLARE_EVENT_CLASS(tasklet, + + TP_PROTO(struct tasklet_struct *t, void *func), + + TP_ARGS(t, func), + + TP_STRUCT__entry( + __field( void *, tasklet) + __field( void *, func) + ), + + TP_fast_assign( + __entry->tasklet = t; + __entry->func = func; + ), + + TP_printk("tasklet=%ps function=%ps", __entry->tasklet, __entry->func) +); + +/** + * tasklet_entry - called immediately before the tasklet is run + * @t: tasklet pointer + * @func: tasklet callback or function being run + * + * Used to find individual tasklet execution time + */ +DEFINE_EVENT(tasklet, tasklet_entry, + + TP_PROTO(struct tasklet_struct *t, void *func), + + TP_ARGS(t, func) +); + +/** + * tasklet_exit - called immediately after the tasklet is run + * @t: tasklet pointer + * @func: tasklet callback or function being run + * + * Used to find individual tasklet execution time + */ +DEFINE_EVENT(tasklet, tasklet_exit, + + TP_PROTO(struct tasklet_struct *t, void *func), + + TP_ARGS(t, func) +); + #endif /* _TRACE_IRQ_H */ /* This part must be outside protection */ diff --git a/kernel/softirq.c b/kernel/softirq.c index c8a6913c067d..1b725510dd0f 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -793,10 +793,15 @@ static void tasklet_action_common(struct softirq_action *a, if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { if (tasklet_clear_sched(t)) { - if (t->use_callback) + if (t->use_callback) { + trace_tasklet_entry(t, t->callback); t->callback(t); - else + trace_tasklet_exit(t, t->callback); + } else { + trace_tasklet_entry(t, t->func); t->func(t->data); + trace_tasklet_exit(t, t->func); + } } tasklet_unlock(t); continue; -- 2.39.1.519.gcb327c4b5f-goog