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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1406C47DDB for ; Tue, 23 Jan 2024 01:45:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 685866B007B; Mon, 22 Jan 2024 20:45:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 60DAE6B0082; Mon, 22 Jan 2024 20:45:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4AE446B0083; Mon, 22 Jan 2024 20:45:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 370776B007B for ; Mon, 22 Jan 2024 20:45:11 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id D342DA1629 for ; Tue, 23 Jan 2024 01:45:10 +0000 (UTC) X-FDA: 81708882780.06.0CB7F5F Received: from out-187.mta1.migadu.com (out-187.mta1.migadu.com [95.215.58.187]) by imf13.hostedemail.com (Postfix) with ESMTP id EC90C20002 for ; Tue, 23 Jan 2024 01:45:07 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=gSxjq6L4; spf=pass (imf13.hostedemail.com: domain of dongtai.guo@linux.dev designates 95.215.58.187 as permitted sender) smtp.mailfrom=dongtai.guo@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1705974308; a=rsa-sha256; cv=none; b=fyvy1oDGbJVykSAtbQtliwdRUBsDjmwjIieGBtKqfhP0OLG5yCoqKL3r48oaDPtT77IhkP OHUcYsbRu3IthYnCF3MRihmbGHChtNKAOjT9ElStcZDzUkUJQ0/rU/1WIDvGofWNCMyWID SBz6q9mJZWm+jkWmOYcrqFpAjw+UT/Q= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=gSxjq6L4; spf=pass (imf13.hostedemail.com: domain of dongtai.guo@linux.dev designates 95.215.58.187 as permitted sender) smtp.mailfrom=dongtai.guo@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1705974308; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8nxUAt2BRtxbUt4m0RqE/VY6i4Z/ctqEoTRjSobIK9M=; b=RQYYnwbaEnzjLH0289rPMhP1rGB/Ko0ZvfdUaAh2GHxhwy6smY/xSFuope0M/I8Nqxl/K2 KTiSDbO1FtQcslAW3lUN6rtoIaaJ+JggkPuiMzWGZ4xTykDeJYSQH2MsF7iWXER24iFf35 hhmgDccjtL/NijuTmMDzzOoq49WRiWo= Date: Tue, 23 Jan 2024 09:44:43 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1705974305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8nxUAt2BRtxbUt4m0RqE/VY6i4Z/ctqEoTRjSobIK9M=; b=gSxjq6L46IdL7730XzmjlUU+g5oXXpyGCe8MDStV7Rl6olklRJYipMuNBqHPhLDmHro+6X m+Jk2/RdhAHnbSCM7UWKHafS5LxdtCVp5M3EhhMP/X6GIRCtA40TP1sjlVCRC7JpM7wgvJ +6AzA3qEg3UoxnuPm45QRHGuM22XsIU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: George Guo To: Steven Rostedt Cc: Masami Hiramatsu , Mathieu Desnoyers , Dennis Zhou , Tejun Heo , Christoph Lameter , Andrew Morton , George Guo , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] percpu: improve percpu_alloc_percpu_fail event trace Message-ID: <20240123094443.00007b20@linux.dev> In-Reply-To: <20240122105700.05e5ee46@gandalf.local.home> References: <20240122073629.2594271-1-dongtai.guo@linux.dev> <20240122105700.05e5ee46@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: EC90C20002 X-Stat-Signature: 3msmhowjtp5wz6t9d9sy1e1eniitaers X-Rspam-User: X-HE-Tag: 1705974307-43538 X-HE-Meta: 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 jjUlGWN0 llofpmKkTdkDlOxyaEWtwOXEcXTn5XTyq1+Zh/xfF/YEqDUdvie7R3zZ/sOVIM1jMP7gAoXm6lWdPM73mmrz+yNYgSVacgGkbOFDERELHB9FIOoohUU0KWcmZBvHpof3hsWHWmojLoc5MWnmUr4lzx5MMWxxeEuT5HK2DhPqnFobvMAqjdr3rCKAZBiBDybTubEUBibO95ISninmuCX7561RhXEm1kKGpSiBUPIKnKaoBe28= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 22 Jan 2024 10:57:00 -0500 Steven Rostedt wrote: > On Mon, 22 Jan 2024 15:36:29 +0800 > George Guo wrote: > > > From: George Guo > > > > Add do_warn, warn_limit fields to the output of the > > percpu_alloc_percpu_fail ftrace event. > > > > This is required to percpu_alloc failed with no warning showing. > > You mean to state; > > In order to know why percpu_alloc failed but produces no warnings, > the do_warn and warn_limit should be traced to let the user know it > was rate-limited. > > Or something like that? > > Honestly, I don't think that the trace event is the proper place to do > that. The trace event just shows that it did fail. If you are > confused to why it doesn't print to dmesg, then you can simply add a > kprobe to see those values as well. > > -- Steve > > > > > Signed-off-by: George Guo > > --- There are two reasons of percpu_alloc failed without warnings: 1. do_warn is false 2. do_warn is true and warn_limit is reached the limit. Showing do_warn and warn_limit makes things simple, maybe dont need kprobe again.