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=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 2FC73C433E2 for ; Mon, 14 Sep 2020 22:57:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8657C206DC for ; Mon, 14 Sep 2020 22:57:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cRqX/Voi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8657C206DC Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A983A6B0073; Mon, 14 Sep 2020 18:57:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A233C8E0001; Mon, 14 Sep 2020 18:57:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 910916B0075; Mon, 14 Sep 2020 18:57:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0098.hostedemail.com [216.40.44.98]) by kanga.kvack.org (Postfix) with ESMTP id 7645E6B0073 for ; Mon, 14 Sep 2020 18:57:34 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 32E4B3628 for ; Mon, 14 Sep 2020 22:57:34 +0000 (UTC) X-FDA: 77263180428.20.tank21_4c001d02710c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 06AAC180C07A3 for ; Mon, 14 Sep 2020 22:57:34 +0000 (UTC) X-HE-Tag: tank21_4c001d02710c X-Filterd-Recvd-Size: 8077 Received: from mail-lf1-f65.google.com (mail-lf1-f65.google.com [209.85.167.65]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Mon, 14 Sep 2020 22:57:33 +0000 (UTC) Received: by mail-lf1-f65.google.com with SMTP id m5so1027701lfp.7 for ; Mon, 14 Sep 2020 15:57:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WViTl0b8x+giGHFZh+rVEKrUPQoCKo+J/50WQCvSoeU=; b=cRqX/VoiJlNpAl8z1euxYLDbFZouqQx0Mt33brymprI2vtjrByuRMCH42vuV/btT6h OV05p0Cytn9A45Ob2T8JxSWLWKRCcbNClVcFRUdmCfOa5zrsHmKyYMsHNY/6dZ9gV+g0 Z8IZWuFtKTlqacd2ikYCTZeFd+UdvXSiw1lsPVPZAE9nGhBRYsYW47ufhafLdKP5LGOU ++fzP4+9m0MsmjaQjTV9Ks/RJm7Nz6m0NC2meTZOjUOeMz4gwIKUxHViVTr8n5pMZ71D mf4ZaigkjBXHPrm1KGiAyFnK+ZPMozHVtg89PLTj6Al/4lCyQjxTgfjPoc3+LROM/sk1 5Rvg== 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=WViTl0b8x+giGHFZh+rVEKrUPQoCKo+J/50WQCvSoeU=; b=fGwN4gmnB3tPLpch1KMTTiYaR2MRZSFSOh7XZWsptyfMpt8GCwrfLWYe67n1PAeTFv u4sVyJ0hMfpcjhlW+FCwKvDg//HyToUJXLZqErjK0oQMkbzw6adLjzxhwC5c5o3cTOzJ XznA7tm7gLKl3oblwJoUFRopk6g9b59HuFXTWwPE+E0O6jgrBjehMBw360tj6mg5gFmO kqg6ISQO21aPWxNZiLaxYoRpIOcw/932EXBcrNeZ1jdBfSYYf27jXSYSh5YT4/+R8wgJ xCOhHHw5zlYhyHPTAfpery9Zq1IVgv+F71RGxsdvGopUlTUYmfM1rtjSP5xjugX6jSlC lkGw== X-Gm-Message-State: AOAM531ciXmTViPjksMNC1+RE9hQdlMa3iXG2clRp/EEW70VVFvJwNp6 I4IqkTZqTZ4CmO6rUJn9trY+K0zvhKawf+31pjUIfQ== X-Google-Smtp-Source: ABdhPJxpmWLKvjsFtNH48os0OOkxFZ9XHBl2kW6WD3M1V9ZZEOYafjadmVljfxRxlpn9ArTUR/z9stoRHFiD3XEOk9w= X-Received: by 2002:a19:4084:: with SMTP id n126mr2701402lfa.54.1600124251790; Mon, 14 Sep 2020 15:57:31 -0700 (PDT) MIME-Version: 1.0 References: <20200913070010.44053-1-songmuchun@bytedance.com> In-Reply-To: From: Shakeel Butt Date: Mon, 14 Sep 2020 15:57:20 -0700 Message-ID: Subject: Re: [External] Re: [PATCH v3] mm: memcontrol: Add the missing numa_stat interface for cgroup v2 To: Muchun Song Cc: Tejun Heo , Li Zefan , Johannes Weiner , Jonathan Corbet , Michal Hocko , Vladimir Davydov , Andrew Morton , Roman Gushchin , Cgroups , linux-doc@vger.kernel.org, LKML , Linux MM , kernel test robot Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 06AAC180C07A3 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 Mon, Sep 14, 2020 at 9:55 AM Muchun Song wrote: > > On Tue, Sep 15, 2020 at 12:07 AM Shakeel Butt wrote: > > > > On Sun, Sep 13, 2020 at 12:01 AM Muchun Song wrote: > > > > > > In the cgroup v1, we have a numa_stat interface. This is useful for > > > providing visibility into the numa locality information within an > > > memcg since the pages are allowed to be allocated from any physical > > > node. One of the use cases is evaluating application performance by > > > combining this information with the application's CPU allocation. > > > But the cgroup v2 does not. So this patch adds the missing information. > > > > > > Signed-off-by: Muchun Song > > > Suggested-by: Shakeel Butt > > > Reported-by: kernel test robot > > > --- > > [snip] > > > + > > > +static struct numa_stat numa_stats[] = { > > > + { "anon", PAGE_SIZE, NR_ANON_MAPPED }, > > > + { "file", PAGE_SIZE, NR_FILE_PAGES }, > > > + { "kernel_stack", 1024, NR_KERNEL_STACK_KB }, > > > + { "shmem", PAGE_SIZE, NR_SHMEM }, > > > + { "file_mapped", PAGE_SIZE, NR_FILE_MAPPED }, > > > + { "file_dirty", PAGE_SIZE, NR_FILE_DIRTY }, > > > + { "file_writeback", PAGE_SIZE, NR_WRITEBACK }, > > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > > > + /* > > > + * The ratio will be initialized in numa_stats_init(). Because > > > + * on some architectures, the macro of HPAGE_PMD_SIZE is not > > > + * constant(e.g. powerpc). > > > + */ > > > + { "anon_thp", 0, NR_ANON_THPS }, > > > +#endif > > > + { "inactive_anon", PAGE_SIZE, NR_INACTIVE_ANON }, > > > + { "active_anon", PAGE_SIZE, NR_ACTIVE_ANON }, > > > + { "inactive_file", PAGE_SIZE, NR_INACTIVE_FILE }, > > > + { "active_file", PAGE_SIZE, NR_ACTIVE_FILE }, > > > + { "unevictable", PAGE_SIZE, NR_UNEVICTABLE }, > > > + { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B }, > > > + { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B }, > > > +}; > > > + > > > +static int __init numa_stats_init(void) > > > +{ > > > + int i; > > > + > > > + for (i = 0; i < ARRAY_SIZE(numa_stats); i++) { > > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > > > + if (numa_stats[i].idx == NR_ANON_THPS) > > > + numa_stats[i].ratio = HPAGE_PMD_SIZE; > > > +#endif > > > + } > > > > The for loop seems excessive but I don't really have a good alternative. > > Yeah, I also have no good alternative. The numa_stats is only initialized > once. So there may be no problem :). > > > > > > + > > > + return 0; > > > +} > > > +pure_initcall(numa_stats_init); > > > + > > > +static unsigned long memcg_node_page_state(struct mem_cgroup *memcg, > > > + unsigned int nid, > > > + enum node_stat_item idx) > > > +{ > > > + VM_BUG_ON(nid >= nr_node_ids); > > > + return lruvec_page_state(mem_cgroup_lruvec(memcg, NODE_DATA(nid)), idx); > > > +} > > > + > > > +static const char *memory_numa_stat_format(struct mem_cgroup *memcg) > > > +{ > > > + int i; > > > + struct seq_buf s; > > > + > > > + /* Reserve a byte for the trailing null */ > > > + seq_buf_init(&s, kmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE - 1); > > > + if (!s.buffer) > > > + return NULL; > > > + > > > + for (i = 0; i < ARRAY_SIZE(numa_stats); i++) { > > > + int nid; > > > + > > > + seq_buf_printf(&s, "%s", numa_stats[i].name); > > > + for_each_node_state(nid, N_MEMORY) { > > > + u64 size; > > > + > > > + size = memcg_node_page_state(memcg, nid, > > > + numa_stats[i].idx); > > > + size *= numa_stats[i].ratio; > > > + seq_buf_printf(&s, " N%d=%llu", nid, size); > > > + } > > > + seq_buf_putc(&s, '\n'); > > > + } > > > + > > > + /* The above should easily fit into one page */ > > > + if (WARN_ON_ONCE(seq_buf_putc(&s, '\0'))) > > > + s.buffer[PAGE_SIZE - 1] = '\0'; > > > > I think you should follow Michal's recommendation at > > http://lkml.kernel.org/r/20200914115724.GO16999@dhcp22.suse.cz > > Here is different, because the seq_buf_putc(&s, '\n') will not add \0 unless > we use seq_buf_puts(&s, "\n"). > Why a separate memory_numa_stat_format()? For memory_stat_format(), it is called from two places. There is no need to have a separate memory_numa_stat_format(). Similarly why not just call seq_printf() instead of formatting into a seq_buf?