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=-13.8 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 autolearn=unavailable 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 9940CC433E0 for ; Thu, 24 Dec 2020 02:45:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6716023137 for ; Thu, 24 Dec 2020 02:45:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728924AbgLXCpL (ORCPT ); Wed, 23 Dec 2020 21:45:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728638AbgLXCpL (ORCPT ); Wed, 23 Dec 2020 21:45:11 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52E83C06179C for ; Wed, 23 Dec 2020 18:44:31 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id m5so423776pjv.5 for ; Wed, 23 Dec 2020 18:44:31 -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=Jj7WfKowDTY95GUHl5uINaRFHYXKJEL5zQtSBC0Z0fg=; b=PFOoA5HWcjgLHoueyb30M9jB+OwHlsdpyon9+H7R8rJlU9xnRZrtahbjlN7Z6celqG ls725GrKSSkcBCWzFLVZ4I5wvU83LKlGCVmuPLQXc/vQzPqvsZquJzPHdqypTNfmtW8I lTjGY9styytdKavQAkRs6LC95X3cWV6eAMJkvfRzVRcGTx+li5vT+AkXUoKMb4oS3a0Z peqQhs/oFkyFJpPRka1GfePlkzgfT5PsBzOVHwijmad4uWufXHs9Qeb7ZqhH19yELs3Z dfr0GxpxE0CGwEsbxGmLF8RWsO+fHR9P9P530nQNyOGClUiHuXgRI2ioXkDx9DQeIVhm +aYA== 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=Jj7WfKowDTY95GUHl5uINaRFHYXKJEL5zQtSBC0Z0fg=; b=JC5Bt9Djn+DooCww5LpzNMoEfIK4BgToJJ8qC0/pDESyWwcnCs3wtcXTMspv8f+qsq k73TOpqHfUPFsXPBj5pp7tPsgqZ5U0/e2Dn6hPJP1d/NGp+z35tS84T5ehdvCTx9tJ3F Z7ySAkx1Ziss6JfBATizqfkeQMBET1U5HZhwQ6SbnGAwycBTsQIk9nmHcIUsVvS6+KqS ZUJYstGUAEMLGaVkUYyWFKM0CjXTRSZ+p9Dw3mKaOG2e7yR4nfra0hH9vYmi38AjQWF4 5bg4Y6aVHOiiinH6JjjXmtA9e+CUHggd/IUjaoaxL08kF/yefJG2cF5JNcPzD5apug8x +hrA== X-Gm-Message-State: AOAM5306yN7e9f5vziIwlHrQcKbo4tDnNztZ9wpm56tt/EAUuA1ykO+L crdAoXvKbOFJXj6XAmG5GvgRKsskW7H5fOoDoDQ1Yw== X-Google-Smtp-Source: ABdhPJwEPvR5VVknSKpSOtEVtKXJ+pYmXsvOtLreyqe7Du7/wgw7c5qRAHb2D8O8tDKNVEeAOx4jfMfNgTEhRZgAcYM= X-Received: by 2002:a17:90a:5405:: with SMTP id z5mr2401755pjh.13.1608777870665; Wed, 23 Dec 2020 18:44:30 -0800 (PST) MIME-Version: 1.0 References: <20201217034356.4708-1-songmuchun@bytedance.com> <20201217034356.4708-8-songmuchun@bytedance.com> In-Reply-To: From: Muchun Song Date: Thu, 24 Dec 2020 10:43:53 +0800 Message-ID: Subject: Re: [External] Re: [PATCH v5 7/7] mm: memcontrol: make the slab calculation consistent To: Shakeel Butt Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Alexey Dobriyan , Andrew Morton , Johannes Weiner , Michal Hocko , Vladimir Davydov , Hugh Dickins , Roman Gushchin , Sami Tolvanen , Feng Tang , Neil Brown , Joonsoo Kim , Randy Dunlap , LKML , linux-fsdevel , Linux MM , Cgroups Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Dec 24, 2020 at 5:21 AM Shakeel Butt wrote: > > On Wed, Dec 16, 2020 at 7:46 PM 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. > > > > To do this we need some code like below: > > > > 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); > > + size += memcg_page_state(memcg, memory_stats[i - 1].idx) * > > + memory_stats[i - 1].ratio; Hi Shakeel, Here is the [i - 1]. > > > > It requires a series of BUG_ONs or comments to ensure these two > > items are actually adjacent and in the right order. So it would > > probably be easier to implement this using a wrapper that has a > > big switch() for unit conversion. > > > > This would fix the ratio inconsistency and get rid of the order > > guarantee. > > > > The commit message is really confusing. It is explaining a situation > which it did not do. I don't see any benefit of mentioning BUG_ONs or > [i-1]s in the message. The patch makes sure that we use the right > ratio for slab. Can you rewrite the commit message and motivate in > just that regard? Yeah, I need rewrite the commit message to make it more clear. However, here is a discussion about this. See https://lore.kernel.org/patchwork/patch/1348611/ Thanks. > > > Signed-off-by: Muchun Song > > --- > > mm/memcontrol.c | 105 +++++++++++++++++++++++++++++++++++--------------------- > > 1 file changed, 66 insertions(+), 39 deletions(-) > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index a40797a27f87..eec44918d373 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -1511,49 +1511,71 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) > > > > struct memory_stat { > > const char *name; > > - unsigned int ratio; > > unsigned int idx; > > }; > > > > static const struct memory_stat memory_stats[] = { > > - { "anon", PAGE_SIZE, NR_ANON_MAPPED }, > > - { "file", PAGE_SIZE, NR_FILE_PAGES }, > > - { "kernel_stack", 1024, NR_KERNEL_STACK_KB }, > > - { "pagetables", PAGE_SIZE, NR_PAGETABLE }, > > - { "percpu", 1, MEMCG_PERCPU_B }, > > - { "sock", PAGE_SIZE, MEMCG_SOCK }, > > - { "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 }, > > + { "anon", NR_ANON_MAPPED }, > > + { "file", NR_FILE_PAGES }, > > + { "kernel_stack", NR_KERNEL_STACK_KB }, > > + { "pagetables", NR_PAGETABLE }, > > + { "percpu", MEMCG_PERCPU_B }, > > + { "sock", MEMCG_SOCK }, > > + { "shmem", NR_SHMEM }, > > + { "file_mapped", NR_FILE_MAPPED }, > > + { "file_dirty", NR_FILE_DIRTY }, > > + { "file_writeback", NR_WRITEBACK }, > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > > - { "anon_thp", PAGE_SIZE, NR_ANON_THPS }, > > - { "file_thp", PAGE_SIZE, NR_FILE_THPS }, > > - { "shmem_thp", PAGE_SIZE, NR_SHMEM_THPS }, > > + { "anon_thp", NR_ANON_THPS }, > > + { "file_thp", NR_FILE_THPS }, > > + { "shmem_thp", NR_SHMEM_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 }, > > - > > - /* > > - * Note: The slab_reclaimable and slab_unreclaimable must be > > - * together and slab_reclaimable must be in front. > > - */ > > - { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B }, > > - { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B }, > > + { "inactive_anon", NR_INACTIVE_ANON }, > > + { "active_anon", NR_ACTIVE_ANON }, > > + { "inactive_file", NR_INACTIVE_FILE }, > > + { "active_file", NR_ACTIVE_FILE }, > > + { "unevictable", NR_UNEVICTABLE }, > > + { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, > > + { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, > > > > /* The memory events */ > > - { "workingset_refault_anon", 1, WORKINGSET_REFAULT_ANON }, > > - { "workingset_refault_file", 1, WORKINGSET_REFAULT_FILE }, > > - { "workingset_activate_anon", 1, WORKINGSET_ACTIVATE_ANON }, > > - { "workingset_activate_file", 1, WORKINGSET_ACTIVATE_FILE }, > > - { "workingset_restore_anon", 1, WORKINGSET_RESTORE_ANON }, > > - { "workingset_restore_file", 1, WORKINGSET_RESTORE_FILE }, > > - { "workingset_nodereclaim", 1, WORKINGSET_NODERECLAIM }, > > + { "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, > > + { "workingset_refault_file", WORKINGSET_REFAULT_FILE }, > > + { "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON }, > > + { "workingset_activate_file", WORKINGSET_ACTIVATE_FILE }, > > + { "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, > > + { "workingset_restore_file", WORKINGSET_RESTORE_FILE }, > > + { "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, > > }; > > > > +/* Translate stat items to the correct unit for memory.stat output */ > > +static int memcg_page_state_unit(int item) > > +{ > > + switch (item) { > > + case MEMCG_PERCPU_B: > > + case NR_SLAB_RECLAIMABLE_B: > > + case NR_SLAB_UNRECLAIMABLE_B: > > + case WORKINGSET_REFAULT_ANON: > > + case WORKINGSET_REFAULT_FILE: > > + case WORKINGSET_ACTIVATE_ANON: > > + case WORKINGSET_ACTIVATE_FILE: > > + case WORKINGSET_RESTORE_ANON: > > + case WORKINGSET_RESTORE_FILE: > > + case WORKINGSET_NODERECLAIM: > > + return 1; > > + case NR_KERNEL_STACK_KB: > > + return SZ_1K; > > + default: > > + return PAGE_SIZE; > > + } > > +} > > + > > +static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, > > + int item) > > +{ > > + return memcg_page_state(memcg, item) * memcg_page_state_unit(item); > > +} > > + > > static char *memory_stat_format(struct mem_cgroup *memcg) > > { > > struct seq_buf s; > > @@ -1577,13 +1599,12 @@ static char *memory_stat_format(struct mem_cgroup *memcg) > > for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { > > u64 size; > > > > - size = memcg_page_state(memcg, memory_stats[i].idx); > > - size *= memory_stats[i].ratio; > > + size = memcg_page_state_output(memcg, memory_stats[i].idx); > > seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); > > > > 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); > > + size += memcg_page_state_output(memcg, > > + NR_SLAB_RECLAIMABLE_B); > > seq_buf_printf(&s, "slab %llu\n", size); > > } > > } > > @@ -6377,6 +6398,12 @@ static int memory_stat_show(struct seq_file *m, void *v) > > } > > > > #ifdef CONFIG_NUMA > > +static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, > > + int item) > > +{ > > + return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); > > +} > > + > > No need to have lruvec_page_state_output() separately as there is just > one user. Just inline it. > > > static int memory_numa_stat_show(struct seq_file *m, void *v) > > { > > int i; > > @@ -6394,8 +6421,8 @@ static int memory_numa_stat_show(struct seq_file *m, void *v) > > struct lruvec *lruvec; > > > > lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); > > - size = lruvec_page_state(lruvec, memory_stats[i].idx); > > - size *= memory_stats[i].ratio; > > + size = lruvec_page_state_output(lruvec, > > + memory_stats[i].idx); > > seq_printf(m, " N%d=%llu", nid, size); > > } > > seq_putc(m, '\n'); > > -- > > 2.11.0 > > -- Yours, Muchun