From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-58-216.mail.qq.com (out162-62-58-216.mail.qq.com [162.62.58.216]) (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 42A686BB44 for ; Sun, 18 Feb 2024 15:34:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.58.216 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708270503; cv=none; b=lC+68GDpkqcyqPrfGD0/U2mOiILMy2qY3Sc2xSNm0q+xB5KsVvM8VO7+dZ48wVAWbW0PiGUMgS9JyeKbp9LXOYfV4LOGXGUDsSOo99OsV9sqy6PnHOgoh6FubHHbcqWYxOawgq2PCH6TAJB7tgFo0kqFVCXR1u7vZSQYkDbFtxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708270503; c=relaxed/simple; bh=F7I2LrOjlEp2qAZiCFZTJ7ZQzHJHlFpK0pNegozALpo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YDtgPuDfQwSx3PWzi9A/VQZIdUS3H2FBjLC2plWIQnRfsn/HWudMqxC4wS/SdnHCfNyychvkTtXKahUiguUWEkY9auMOD/RrxOeUxlc69L1O2Fp3+kIYcA7RM3Yt/NdWavQUbOSF9u9EkB6AEk2zuBsLWYcVZFqzCExee2SMfWg= 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=NEyC/sQF; arc=none smtp.client-ip=162.62.58.216 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="NEyC/sQF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1708270194; bh=4fRSGqhQu6+Ft3OxeuS/RVv3QuBc/38aa5FYMsAwInQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=NEyC/sQFF0ixc+ZKeL9A4icuLM++rrtp9M1jqiO0Sk4KQJSxA57DPCs4e0tQRD5nd Wb615ZrZshF8gBtDlLECrZNs0jdDlGFx8l6Zbyu1VUgJKsuNq6bjl8ZCZBj8bmrhN3 ITr9yPB7/LR8zMOkBAC+tov26hzX79T2N4auGseY= Received: from [IPV6:2409:8a60:2a63:47a0:d83a:fd45:cca4:d0ee] ([2409:8a60:2a63:47a0:d83a:fd45:cca4:d0ee]) by newxmesmtplogicsvrszc5-2.qq.com (NewEsmtp) with SMTP id 41B8DAD0; Sun, 18 Feb 2024 23:16:27 +0800 X-QQ-mid: xmsmtpt1708269387thxny1wqh Message-ID: X-QQ-XMAILINFO: Mm/8i8/T4yneRpBbz2MOtsPciZmyzYOjaxvYxN8HR0g0JTUubk0sppxpk5Oa9B xW6uDgg5k5v8ayDO8S/9ajk3yCQZTO3JIxkeZJy7sc2KL69jiLy5jTy73uKgAAT/S9l3YJVj4uC0 Jde4XZhT3mEHGxg01LYIXXA7IfEl5YOz7j0UFf1i0dNvA8d92faKM6gFId8oDxHH/v+75nFYbP8B uAPRIz1ndv6B39e4121bJxbm8wtF5DmXzkJZ/nsHcbK0PJT+eDlti8oelkPJe8kC8Lsn0JauEgPI Afk0gXaLvPo+4Dmje828cJ4b8Or5kp16r9X/PIpDXKk1mgrXk3XpUY3xkFXrLXIQdOi0305W2BMy NKgAnOZ6LUjIB+WOg14lBRVFZbPywKQhEg4GcxYLzzNbDkuabqaEwozzY/YDYvgyG46Wt/l5DRhE CN1+SoiBIwUnOL6dKAqa++NH5ptvD0k5gYxIMcz4PmzmzVbOBZZP/s3QxtDCKBLsiVsN/f6LU88i iIyngNfFaoDfRTDYzaFmWUz4TOq474toORkOmuZRuS2GK8vJrNVEQQxPJ+PQrOuheU5yXVEQeFdA ahkkj6D/kGc8+j5yWxn2x+NcroQ53oC5GT+o9TXUivKB24VwnF8y6WFM6/whUEVLx5lg/lfPj9rZ cr8ysK0RmqMz3GnzjbKU+q6PihcRz7qcgUAmlbY0ZwDS/KuW7Swlbu7BIc347424C8/UJMBKAhwa HZ73R7NNK1yEQixWQ8kGSTF1M4dpjOGiNPbZ6kY0uJdzPSSFUlnDvtK1xQe4y6kK33lo/Os02Xmr SagCKUU+ZlKPZWzM7fzysPdH07GWcL9BgRzOBIAoDbYOUGt8q+DPYptBN3fVazwZ1qJTnRA51g0d d8RTDN8N5SqEAHhzrFCRwXgOuSJ6CLAiP+6Rx1OPM0ebCoisy9AIl4YJneq0TkMcHP5zROrku2kx szjoy3sH1GO37nTXVncvZ0ylV+Rd6OM3iL8n0UTNV0YFGmNBFPBasLufnRS9yJ X-QQ-XMRINFO: MPJ6Tf5t3I/ycC2BItcBVIA= X-OQ-MSGID: Date: Sun, 18 Feb 2024 23:16:27 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] coredump debugging: add a tracepoint to report the coredumping To: Oleg Nesterov Cc: Steven Rostedt , Masami Hiramatsu , Ingo Molnar , Mathieu Desnoyers , Mel Gorman , Peter Zijlstra , linux-kernel@vger.kernel.org References: <20240217104924.GB10393@redhat.com> Content-Language: en-US From: Wen Yang In-Reply-To: <20240217104924.GB10393@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/2/17 18:49, Oleg Nesterov wrote: > On 02/17, wenyang.linux@foxmail.com wrote: >> 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. >> >> Add the new trace_sched_process_coredump() into coredump_task_exit(), >> this way a user-space monitor could easily wait for the exits and >> potentially make some preparations in advance. > Can't comment, I never know when the new tracepoint will make sense. > > Stupid question. > Oleg. Thanks for your help. trace_sched_process_exit() is located after the PF_EXITING flag is set, so it could not be moved to there. Could we make the following modifications? diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index dbb01b4b7451..53e9420540dc 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -334,6 +334,13 @@ DEFINE_EVENT(sched_process_template, sched_process_exit,              TP_PROTO(struct task_struct *p),              TP_ARGS(p)); +/* + * Tracepoint for killing a task by a signal: + */ +DEFINE_EVENT(sched_process_template, sched_process_kill, +            TP_PROTO(struct task_struct *p), +            TP_ARGS(p)); +  /*   * Tracepoint for waiting on task to unschedule:   */ diff --git a/kernel/signal.c b/kernel/signal.c index 9b40109f0c56..571342799824 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2866,6 +2866,7 @@ bool get_signal(struct ksignal *ksig)                  * Anything else is fatal, maybe with a core dump.                  */                 current->flags |= PF_SIGNALED; +               trace_sched_process_kill(current);                 if (sig_kernel_coredump(signr)) {                         if (print_fatal_signals) -- Best wishes, Wen > >> Signed-off-by: Wen Yang >> Cc: Oleg Nesterov >> Cc: Steven Rostedt >> Cc: Masami Hiramatsu >> Cc: Mathieu Desnoyers >> Cc: Ingo Molnar >> Cc: Mel Gorman >> Cc: Peter Zijlstra >> Cc: linux-kernel@vger.kernel.org >> --- >> include/trace/events/sched.h | 7 +++++++ >> kernel/exit.c | 1 + >> 2 files changed, 8 insertions(+) >> >> diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h >> index dbb01b4b7451..ce7448065986 100644 >> --- a/include/trace/events/sched.h >> +++ b/include/trace/events/sched.h >> @@ -334,6 +334,13 @@ DEFINE_EVENT(sched_process_template, sched_process_exit, >> TP_PROTO(struct task_struct *p), >> TP_ARGS(p)); >> >> +/* >> + * Tracepoint for a task coredumping: >> + */ >> +DEFINE_EVENT(sched_process_template, sched_process_coredump, >> + TP_PROTO(struct task_struct *p), >> + TP_ARGS(p)); >> + >> /* >> * Tracepoint for waiting on task to unschedule: >> */ >> diff --git a/kernel/exit.c b/kernel/exit.c >> index 493647fd7c07..c11e12d73f4e 100644 >> --- a/kernel/exit.c >> +++ b/kernel/exit.c >> @@ -425,6 +425,7 @@ static void coredump_task_exit(struct task_struct *tsk) >> self.next = xchg(&core_state->dumper.next, &self); >> else >> self.task = NULL; >> + trace_sched_process_coredump(tsk); >> /* >> * Implies mb(), the result of xchg() must be visible >> * to core_state->dumper. >> -- >> 2.25.1 >>