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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52C8AC2BA19 for ; Fri, 24 Apr 2020 02:38:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 116E82075A for ; Fri, 24 Apr 2020 02:38:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="Ddtvcj1n" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 116E82075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9812F8E0005; Thu, 23 Apr 2020 22:38:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 912CD8E0003; Thu, 23 Apr 2020 22:38:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F8DA8E0005; Thu, 23 Apr 2020 22:38:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0045.hostedemail.com [216.40.44.45]) by kanga.kvack.org (Postfix) with ESMTP id 640AD8E0003 for ; Thu, 23 Apr 2020 22:38:56 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 27FFA180AD81F for ; Fri, 24 Apr 2020 02:38:56 +0000 (UTC) X-FDA: 76741191072.25.straw26_88295f285300b X-HE-Tag: straw26_88295f285300b X-Filterd-Recvd-Size: 4815 Received: from mail-qt1-f195.google.com (mail-qt1-f195.google.com [209.85.160.195]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Fri, 24 Apr 2020 02:38:55 +0000 (UTC) Received: by mail-qt1-f195.google.com with SMTP id z90so6781821qtd.10 for ; Thu, 23 Apr 2020 19:38:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ldECbwkx2KzC+gjraTT+5K+gEB5icL0nRQIC9XPuGkU=; b=Ddtvcj1n3A2iRjbjaGXKb42PeJjcfV41WkfP5jznQsOoAXtq4Aq0YAI+jC0sCsKnvx 3ZUlrZSEr3HUWZp9NZZUR0WJE+gtm9Uewof/FeE8jRb+3r2wee/XOWlmOAmQMF85e2cW QBsM3r65qePLq09dyRU//VQ1HxsdWxOOkQ5hV/kB6m09C/86n/XsphQWiUecxZrtcy5j EFolcHbY7QejWuMaqC22oW+PcDruwHWEGwRIKo9ovvU5K4MZuxo++hLjAlegnyZ2T3hU mBUEvRefs3krgdLJT5E4/GkLAylz+osjnZ55rZwa2wXOUEN0L6QFj3VRgJErkjjZe4Gy UfrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ldECbwkx2KzC+gjraTT+5K+gEB5icL0nRQIC9XPuGkU=; b=BITfocgvv3+/AFaii7av2L4pEtOdm5R2tr41tP4IP4Avk8HINjNt/Gxas2H0kQcTPk WhL5ljFBeKk9c9frw76Gk1RKRG+C5AhizAZaSA7xWPEs30FOt4R/i+slR7skRr90tOFF 5Reayg4Dc8PNgdfNHNQQIcU/z/h96G5TL/vstXiifkCmMugD1un1zjbmYpjPl/KYg2Zw WTV6WmFnHSMTUwGfwJXcT/RNGCAakj5xuX3n8yTZGIu5dx0lMNkG/9ibLhwv0GUjGzJ/ 8e8MSLtqjNoZcfMa06dzf97+i+K/DvG0YHhIvx0wOG5UJ1/4OgO7Af0RiWPSwJmjoxfQ +t3A== X-Gm-Message-State: AGi0PuaqKeniPkSpJMI48lRS3uV+vh5EFLZBXcRHZJvu8Fjnv3uNhW4K i5QLORSCPg3aKSY/WeWXMNWIBQ== X-Google-Smtp-Source: APiQypJF/lU+gP1rF4zPkq/e1xGtqTYkCAApZ1rxn1wi2o2lKf14w530nRIMlfW+DykVCLSYhsCYQw== X-Received: by 2002:ac8:7552:: with SMTP id b18mr6922401qtr.312.1587695934661; Thu, 23 Apr 2020 19:38:54 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::921]) by smtp.gmail.com with ESMTPSA id g92sm3250225qtd.42.2020.04.23.19.38.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Apr 2020 19:38:54 -0700 (PDT) Date: Thu, 23 Apr 2020 22:38:52 -0400 From: Johannes Weiner To: Andrew Morton Cc: Shakeel Butt , Roman Gushchin , Michal Hocko , Linux MM , Cgroups , LKML Subject: Re: [PATCH] memcg: optimize memory.numa_stat like memory.stat Message-ID: <20200424023852.GA464082@cmpxchg.org> References: <20200304022058.248270-1-shakeelb@google.com> <20200305204109.be23f5053e2368d3b8ccaa06@linux-foundation.org> <20200423161009.973c645420a4d17ded2a67ee@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200423161009.973c645420a4d17ded2a67ee@linux-foundation.org> 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: On Thu, Apr 23, 2020 at 04:10:09PM -0700, Andrew Morton wrote: > From: Shakeel Butt > Subject: mm/memcg: optimize memory.numa_stat like memory.stat > > Currently reading memory.numa_stat traverses the underlying memcg tree > multiple times to accumulate the stats to present the hierarchical view of > the memcg tree. However the kernel already maintains the hierarchical > view of the stats and use it in memory.stat. Just use the same mechanism > in memory.numa_stat as well. > > I ran a simple benchmark which reads root_mem_cgroup's memory.numa_stat > file in the presense of 10000 memcgs. The results are: > > Without the patch: > $ time cat /dev/cgroup/memory/memory.numa_stat > /dev/null > > real 0m0.700s > user 0m0.001s > sys 0m0.697s > > With the patch: > $ time cat /dev/cgroup/memory/memory.numa_stat > /dev/null > > real 0m0.001s > user 0m0.001s > sys 0m0.000s > > [akpm@linux-foundation.org: avoid forcing out-of-line code generation] > Link: http://lkml.kernel.org/r/20200304022058.248270-1-shakeelb@google.com > Signed-off-by: Shakeel Butt > Reviewed-by: Andrew Morton > Cc: Johannes Weiner > Cc: Roman Gushchin > Cc: Michal Hocko > Signed-off-by: Andrew Morton Ouch, yes. That makes sense. Acked-by: Johannes Weiner