From nobody Sun Feb 8 12:19:58 2026 Received: from out203-205-251-60.mail.qq.com (out203-205-251-60.mail.qq.com [203.205.251.60]) (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 07ECC1FA5 for ; Sun, 10 Mar 2024 05:25:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.205.251.60 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710048362; cv=none; b=b8PsrMSAJfTvlSsmXKtV5QKLurxrVU1kaW0BUA5hL08TY164YuCRAds1GZ26NWxYMu3ey70onfaMXuAkqhWgVc/VCSDEP6Sjpj4KkRYNLOQkQiSkQTp+Pbtri6GG/BE9W7O9zf4tyNi5SP7wQ3lmG8Tuuj+RFlhxvXDULKF5stE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710048362; c=relaxed/simple; bh=f2BLX5fET0RUFWfLQGHErQZOtiUviwwQTOr1HfZUlKw=; h=Message-ID:From:To:Cc:Subject:Date:MIME-Version; b=BF2vx3lUunDKHaylLVX0dN15eeB1KaS1PLgp6NSB/oSXNf2FNRWUQrOn72p5jOC2LNB2ZE3tn7eCH/cEO3IGO9+LRkHemE2XrevF2c8OUWmVI59Z0bMQmaFetlqvL5wrj3uA9A0DiiHzZERForVETUW+O2WL+flnpPoynl6RxZQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foxmail.com; spf=pass smtp.mailfrom=foxmail.com; dkim=pass (1024-bit key) header.d=foxmail.com header.i=@foxmail.com header.b=UWa+EZgO; arc=none smtp.client-ip=203.205.251.60 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foxmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foxmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=foxmail.com header.i=@foxmail.com header.b="UWa+EZgO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1710048356; bh=RFbrlE8bKyXh1wQvXS2b2V9UYhLWFs0ZKai1mg42aZ4=; h=From:To:Cc:Subject:Date; b=UWa+EZgO8D9bxIDkhObskjHv8DS3nw0FRYNYX6e2pNFLSX/vXVfUIcBOwoDgskqPp 1Juc2ak8IX7Vr+2izm5DPw1+CH7qvr/25VzEx1dOCb83RaXS5kHDz4pmqU+YdE4Jgr 4t5+WGnNQkvQ02VQZ6ZNCCtbLeFKJ43meikDaRRQ= Received: from localhost.localdomain ([2409:8a60:2a60:3eb0:f685:8358:c9e1:8bef]) by newxmesmtplogicsvrszb9-0.qq.com (NewEsmtp) with SMTP id 6749F8FA; Sun, 10 Mar 2024 13:25:52 +0800 X-QQ-mid: xmsmtpt1710048352t52ifyxyr Message-ID: X-QQ-XMAILINFO: OZsapEVPoiO6IKq8JVkXKogtJegkw40HF9lvXESOQ0BxLnK52Kp4sM5WW2TBL+ StaxctsMbu1tcZoVstbdkxpckc9j9ZUoJSidPHv9Tkq7U/KveKhM4Q3majfdDgY+KZQFUDfTRcZl wOPiMg4E8SnSwZK30O2sTXmguFMTWgZrlxF0y2/8SP3fKEhFr6zAe47XQwkByagoYiLz4JFqbKzm 2RFts/KWPZ0z85khLZAnfWeSRGPpGESkg4gqqOHCvrYgDb74eAMu49uIrfTC9PuJKCE3eplj4Nff P0d5f3ioXEOdSVoeI/Pthbt5IZIv8fsMBLUXt2g5E/X4e/2rF/a/ruR/KVSZJqvbNLPUSMaPK3Xp IUkqzJUyEUtpxkvqHrzaLXuPH/UYpiV4PgGl9r2k8HVjHGv2yuZZgzyv1xfLZZLQ6SLkYki+Zx84 JRaYlN0D6Mg/3Nfa/IUsRlq/V6MtHNjsx6pV/u8U0lUcwjZUDfayiMFWPTs2zGPRGWUDgxJAf0y5 shmlu+7WLuUG9Ky+X7VTmJdJio64W2DOU8elFEPWuuYOKC6rrUy6fWR6ykL23l+ePZTJgnBEgoUA dAqqon+LG8Rrg4lXY1K5IMCqOBvVaLFud1ur8BY1yI8yKlWd610d4uzjjSZtsJN7zdqX4w12C6OI GL+josLCiq5RByb3an2q1aeezSzDbZxE4pyJ+iufLQbs+fa9Rdh8qm/wFeMlQgI+iB4eXl1xk/oA WYshM5JqwtRKUBn0MPbQipSK7WRmFlz5q3Lc1m5tgS8IRH1US7ov1OEvxpcYbp9UJLtSwzsevP4w hSbuWAKX5A2p/jIEAxZigriygS7d1PnzDVY6TU+sTMDK+J7EfLG+VIh5DvtmNj3rj0/BJiY4Mkxe Mi4dochRoHIG2Ljubrge4z7/1XfIpH7sjzaB1UAZca2fwMPvNCkVIMyj3KZNjI39sz5EWVljWYra ykfKlIKdZtebdhjDsRuwBwKuiqIOLlQ6bbJrKaBdIvXD+G/tgvgRhDA7XIKGam65NqUfWLkoPc2B 5Noly/6gEEAv7BG5Eln8/K+1qq7nY= X-QQ-XMRINFO: MPJ6Tf5t3I/ycC2BItcBVIA= From: wenyang.linux@foxmail.com To: Steven Rostedt , Andrew Morton , Ingo Molnar Cc: Wen Yang , Oleg Nesterov , Mathieu Desnoyers , Masami Hiramatsu , Christian Brauner , Mel Gorman , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: [PATCH v3] exit: move trace_sched_process_exit earlier in do_exit() Date: Sun, 10 Mar 2024 13:25:29 +0800 X-OQ-MSGID: <20240310052529.294895-1-wenyang.linux@foxmail.com> X-Mailer: git-send-email 2.25.1 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: Wen Yang Currently coredump_task_exit() takes some time to wait for the generation of the dump file. But if the user-space wants to receive a notification as soon as possible it maybe inconvenient. Move trace_sched_process_exit() earlier in do_exit(). This way a user-space monitor could detect the exits and potentially make some preparations in advance. Oleg initially proposed this suggestion, and Steven further provided some detailed suggestions, and Mathieu carefully checked the historical code and said: : I've checked with Matthew Khouzam (maintainer of Trace Compass) : which care about this tracepoint, and we have not identified any : significant impact of moving it on its model of the scheduler, other : than slightly changing its timing. : I've also checked quickly in lttng-analyses and have not found : any code that care about its specific placement. : So I would say go ahead and move it earlier in do_exit(), it's : fine by me. Suggested-by: Oleg Nesterov Suggested-by: Steven Rostedt Suggested-by: Mathieu Desnoyers Signed-off-by: Wen Yang Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Ingo Molnar Cc: Andrew Morton Cc: Christian Brauner Cc: Mel Gorman Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org --- kernel/exit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/exit.c b/kernel/exit.c index 493647fd7c07..2cff6533cb39 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -826,6 +826,7 @@ void __noreturn do_exit(long code) =20 WARN_ON(tsk->plug); =20 + trace_sched_process_exit(tsk); kcov_task_exit(tsk); kmsan_task_exit(tsk); =20 @@ -866,7 +867,6 @@ void __noreturn do_exit(long code) =20 if (group_dead) acct_process(); - trace_sched_process_exit(tsk); =20 exit_sem(tsk); exit_shm(tsk); --=20 2.25.1