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 EE000CEDDA9 for ; Thu, 10 Oct 2024 01:08:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 35DA96B0085; Wed, 9 Oct 2024 21:08:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 30DF06B0088; Wed, 9 Oct 2024 21:08:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1FCAF6B0089; Wed, 9 Oct 2024 21:08:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 01C9A6B0085 for ; Wed, 9 Oct 2024 21:08:47 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 953D816067F for ; Thu, 10 Oct 2024 01:08:44 +0000 (UTC) X-FDA: 82655907894.16.C8B48AC Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf05.hostedemail.com (Postfix) with ESMTP id 9CEB210000A for ; Thu, 10 Oct 2024 01:08:44 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of "SRS0=PjQY=RG=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=PjQY=RG=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728522388; 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; bh=c5Se8xVglk+7FTpN1UjmBF7hn0tGgQ/dLOYqD7iDp+s=; b=W5NgSQQeHECVcvz0aRhN1Zp/IKcItDv6Ml7hpfG2YmFnYNTaiQxD0ium+Uw5lH1vCBiDRT 2h/PAuw5FY8RTxCZ8I1gMR7WNMSeLQfily2fRJZFb1shi4bMyA11m42Sxi/41bht95rwM7 UME9n69lGYtkSlDrGpqQ/G7M/YOwnCQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1728522388; a=rsa-sha256; cv=none; b=4fyODrV8YAgwyHuv0jIRlhv60VblZE6vZHSVoNnl/vA3xDZCDSjDJ2C4+AVA/8FNIQones dEVRJChN9aYjetuTkEMMpu/KlXOZXBkkLt0GwXXlsBrxzuayM27yAVJKf524uQMqhV4Ofa Kxm5QDQ4TMsKqGhXThGmhqoJTIvKvtY= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of "SRS0=PjQY=RG=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=PjQY=RG=goodmis.org=rostedt@kernel.org"; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 2F5EB5C5A8B; Thu, 10 Oct 2024 01:08:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 508C5C4CEC3; Thu, 10 Oct 2024 01:08:42 +0000 (UTC) Date: Wed, 9 Oct 2024 21:08:48 -0400 From: Steven Rostedt To: Yosry Ahmed Cc: Shakeel Butt , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , JP Kobryn , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team Subject: Re: [PATCH] memcg: add tracing for memcg stat updates Message-ID: <20241009210848.43adb0c3@gandalf.local.home> In-Reply-To: References: <20241010003550.3695245-1-shakeel.butt@linux.dev> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: rrghtbsuyuo11atjqz8h8eazyb4hqfy8 X-Rspamd-Queue-Id: 9CEB210000A X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1728522524-71396 X-HE-Meta: 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 Uyx4HV7t 1x45rG8gJ9l5x9ye0T1ddIFr97t000Ksh1mLxcqt+w7Wpx4XDjrpVFKGYrXMAnQwFNMW1TtDsANaAsBPrJ3R44UhumEmMYb3FOlz1VfqalJn70aREBlEvxAtUOlvOsrLHC+Dd0boPTc3vd0tRkmy8pqa3LdrMPOQsbcbRTWbGrZIfMSaBk6uKAttR7tJVXzY6hixOatn9fgKVKgde2ke3Q6nup0EjKaAIEAaRtM4bNXT4tYQxs9wE1o50xEyT/iEE1DKmKVOT4ah2kmK7F1pFFxUdIGlf+iXZ7W6auYUvu42o01BzP3sIxbIJVw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Wed, 9 Oct 2024 17:46:22 -0700 Yosry Ahmed wrote: > > +++ b/mm/memcontrol.c > > @@ -71,6 +71,10 @@ > > > > #include > > > > +#define CREATE_TRACE_POINTS > > +#include > > +#undef CREATE_TRACE_POINTS > > + > > #include > > > > struct cgroup_subsys memory_cgrp_subsys __read_mostly; > > @@ -682,7 +686,9 @@ void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx, > > return; > > > > __this_cpu_add(memcg->vmstats_percpu->state[i], val); > > - memcg_rstat_updated(memcg, memcg_state_val_in_pages(idx, val)); > > + val = memcg_state_val_in_pages(idx, val); > > + memcg_rstat_updated(memcg, val); > > + trace_mod_memcg_state(memcg, idx, val); > > Is it too unreasonable to include the stat name? > > The index has to be correlated with the kernel config and perhaps even > version. It's not a big deal, but if performance is not a concern when > tracing is enabled anyway, maybe we can lookup the name here (or in > TP_fast_assign()). What name? Is it looked up from idx? If so, you can do it on the reading of the trace event where performance is not an issue. See the __print_symbolic() and friends in samples/trace_events/trace-events-sample.h -- Steve