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=-13.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 EBE14C64E7C for ; Thu, 3 Dec 2020 02:54:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1F5A3221FB for ; Thu, 3 Dec 2020 02:54:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F5A3221FB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bytedance.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8A43A6B005C; Wed, 2 Dec 2020 21:54:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8558B6B005D; Wed, 2 Dec 2020 21:54:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 76ACE6B0068; Wed, 2 Dec 2020 21:54:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0223.hostedemail.com [216.40.44.223]) by kanga.kvack.org (Postfix) with ESMTP id 607BC6B005C for ; Wed, 2 Dec 2020 21:54:12 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2FF398249980 for ; Thu, 3 Dec 2020 02:54:12 +0000 (UTC) X-FDA: 77550451944.26.lock01_060bf9e273b8 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id 0AACC1804B676 for ; Thu, 3 Dec 2020 02:54:12 +0000 (UTC) X-HE-Tag: lock01_060bf9e273b8 X-Filterd-Recvd-Size: 6018 Received: from mail-pj1-f65.google.com (mail-pj1-f65.google.com [209.85.216.65]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Dec 2020 02:54:11 +0000 (UTC) Received: by mail-pj1-f65.google.com with SMTP id p21so1359665pjv.0 for ; Wed, 02 Dec 2020 18:54:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GDcWWcWtZ2CIT3OcyxlFsQ8cIBNK++QYLLtJ9vIR6kA=; b=sDSPa8a747MqIOZ3kxtOh3eGCz6jS+hENFwV7LofZs09YNQAcrvfmOunXFm1AN3MNz 8qIpEx3Esxeo1AKK3mb9soO9OCpbXBSWyeHgFnOhkYY0yvKmUFXLGjTTByFJ+sewzvsd DNIjXqfF7QMMLXx0Q+ISBY6DsryjqzemNv1LEIxt7a1/rMC9LqD0539AzqRZKyX2jjQA tB0+wgPGI/SuFEESCOsYdE6zo++XPwYovqBs2tq/nSnzwVIcXTidTqB33Jhunv9+Wubh HVHhV8zsjUOOT4c9C/SaEZUBpmV4DM3n7Oye0Xtri3kHVVcu/5ac4U7J2P38HI9ITuPU LEVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GDcWWcWtZ2CIT3OcyxlFsQ8cIBNK++QYLLtJ9vIR6kA=; b=QlnPnnQiMW+uBW3UJzq5i3SOAtLcXVgqYrnXAwzJDKDIx3mK8cGS1r4v5OpSWpnmV9 LR94OQGb6HtK9/I3GhQoH/UBIKmYo/8EMZhGlIQjuj4nBBEe7hGR3Jpa4detlyoBRIYs F+AcMoOwNghCDlban3T9YSQm/UHaiaoQVednVz9/DcQetXf9ZsuzZpRIQVoU5gId2fpY IwNCo3JGRhpHYEJOJRa5jPDj2WO67RK+9xAVum8HuIT3SBiGkS2pB2xBA+w8z62wdtGS WPqDwPVOqIZICEwNGRDhkD/k3SZhBVGs8n8Zl7cgEaVbHsDgnHnHj2H5WAH+M7nrjRkQ uGug== X-Gm-Message-State: AOAM533yDjx8pYUhiJlqrP38QkmpbIXO4oO9RG1GXTOCV8zAkEPPLvJd O4ilaKEzrxnGaUC8gbuK4CcKteT4eXnTtEwJtPD8eQ== X-Google-Smtp-Source: ABdhPJzbn6ILlMeH2YCPHyVeHEwZs+Ygkrr5yTMIKPfugRZMa00bTRkTBHV5D83EzuP9SV2sBAF/rx93pjmJOcAxYT4= X-Received: by 2002:a17:90a:c588:: with SMTP id l8mr972593pjt.147.1606964050137; Wed, 02 Dec 2020 18:54:10 -0800 (PST) MIME-Version: 1.0 References: <20201202121434.75099-1-songmuchun@bytedance.com> <20201202211646.GA1517142@carbon.lan> In-Reply-To: <20201202211646.GA1517142@carbon.lan> From: Muchun Song Date: Thu, 3 Dec 2020 10:53:33 +0800 Message-ID: Subject: Re: [External] Re: [PATCH] mm/memcontrol: make the slab calculation consistent To: Roman Gushchin Cc: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Cgroups , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" 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, Dec 3, 2020 at 5:16 AM Roman Gushchin wrote: > > On Wed, Dec 02, 2020 at 08:14:34PM +0800, Muchun Song wrote: > > Although the ratio of the slab is one, we also should read the ratio > > from the related memory_stats instead of hard-coding. And the local > > variable of size is already the value of slab_unreclaimable. So we > > do not need to read again. Simplify the code here. > > > > Signed-off-by: Muchun Song > > --- > > mm/memcontrol.c | 22 +++++++++++++++++----- > > 1 file changed, 17 insertions(+), 5 deletions(-) > > Hi Muchun! > > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 9922f1510956..03a9c64560f6 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -1545,12 +1545,22 @@ static int __init memory_stats_init(void) > > int i; > > > > for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { > > + switch (memory_stats[i].idx) { > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > > - if (memory_stats[i].idx == NR_ANON_THPS || > > - memory_stats[i].idx == NR_FILE_THPS || > > - memory_stats[i].idx == NR_SHMEM_THPS) > > + case NR_ANON_THPS: > > + case NR_FILE_THPS: > > + case NR_SHMEM_THPS: > > memory_stats[i].ratio = HPAGE_PMD_SIZE; > > + break; > > #endif > > + case NR_SLAB_UNRECLAIMABLE_B: > > + VM_BUG_ON(i < 1); > > + VM_BUG_ON(memory_stats[i - 1].idx != NR_SLAB_RECLAIMABLE_B); > > Please, convert these to BUILD_BUG_ON(), they don't have to be runtime checks. Agree. But here we cannot use BUILD_BUG_ON(). The compiler will complain about it. > > > > + break; > > + default: > > + break; > > + } > > + > > VM_BUG_ON(!memory_stats[i].ratio); > > VM_BUG_ON(memory_stats[i].idx >= MEMCG_NR_STAT); > > } > > @@ -1587,8 +1597,10 @@ static char *memory_stat_format(struct mem_cgroup *memcg) > > seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); > > > > Can you, please, add a small comment here stating that we're printing > unreclaimable, reclaimable and the sum of both? It will simplify the reading of the code. Will do. > > > if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { > > - size = memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) + > > - memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE_B); > > + int idx = i - 1; > > + > > + size += memcg_page_state(memcg, memory_stats[idx].idx) * > > + memory_stats[idx].ratio; > > seq_buf_printf(&s, "slab %llu\n", size); > > } > > } > > Otherwise the patch looks good to me! Please, feel free to add > Acked-by: Roman Gushchin > after addressing my comments. > > Thanks! > > -- > > 2.11.0 > > -- Yours, Muchun