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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 F3BA0C64E7A for ; Thu, 3 Dec 2020 05:02:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A42D6208A9 for ; Thu, 3 Dec 2020 05:02:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727077AbgLCFCG (ORCPT ); Thu, 3 Dec 2020 00:02:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726412AbgLCFCF (ORCPT ); Thu, 3 Dec 2020 00:02:05 -0500 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 692A2C061A4E; Wed, 2 Dec 2020 21:01:25 -0800 (PST) Received: by mail-ej1-x643.google.com with SMTP id n26so1529090eju.6; Wed, 02 Dec 2020 21:01:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=qDiLxMMzlVhCPYFL3c1sMpl1OLJgVHvtqSY0eugUJXg=; b=gFVhROOfpycTkoucWqzPkT6Dq5O5dYZoperXvoo3LEYKuTjUaQ0PYyYPJkJ+9iw4Lg BFjvXBI0Nxq7CcBQn8h61Vx8rKpd8W3YI/9/D8FzchbOm+ojq86DvXUsiTLceThqVzMW Kh9DvkVcGaeICIAAEy7DVVvu6xiQIouDMuXZAcfaDURfrj/OuAdXYc7cgSl2qQs7394m qpy4hAToGrP9N1/e6LmzXfL8JN2nA8YJUc9gXCjQWvPRET+hSC0gZS8FIN0FcRphcVh0 MEf80EI78yyuTfhHTull9948v+I08ODRgdug5qHcvWtyLv4HPZBl5JWoYUPVO01SQGE4 FYWg== 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=qDiLxMMzlVhCPYFL3c1sMpl1OLJgVHvtqSY0eugUJXg=; b=TDQcRou+ri31/3dphbIXFac6vKP2h03zgnxKrKPUS8zMSTJjTf0ttO4xaQM1V0Llbh 8iOeq4kV33CMULHFRWN752w41irlg/djP5NLEjdfVBgub/okf1U+inBtF9msE+qNBeGP NzOnxY7V0BDfceZxXdnWogZn2KamO8bGiKBur//TNbc2BgvAdJ0qc4eC+CEVwoi1XdRt FiZ+u+YoOqT40mdBuN8KWhHxk7d1eLGvBVU/drH3ziXhv3zRqCZe5vORnVBgpc/GA0N4 n6SCINKEPsmnJCBKPSdxp3NAE1gLuSw1ZtVn6MPfLZx4p7Zh1JjO6K37sifiOqQqPgX5 eFXw== X-Gm-Message-State: AOAM532z8+CTxJCXp8mjypHU7iXSkF+yxNRU35BBTi6ItIj3SOc3EEx4 kdnPw2t66d17zLntCtgHmpQ6lpgd7tvO+gAPs2E= X-Google-Smtp-Source: ABdhPJxvKUyHaptjmY3o3caBRtGvalJO4cdx2sjUT8zU/E5TuHjwWHAIhFBitBjyWdfH9+J/qBxN7LforJ+8ny2H8lE= X-Received: by 2002:a17:906:7cc6:: with SMTP id h6mr969315ejp.161.1606971684136; Wed, 02 Dec 2020 21:01:24 -0800 (PST) MIME-Version: 1.0 References: <20201202182725.265020-1-shy828301@gmail.com> <20201202182725.265020-7-shy828301@gmail.com> <20201203030841.GH1375014@carbon.DHCP.thefacebook.com> In-Reply-To: <20201203030841.GH1375014@carbon.DHCP.thefacebook.com> From: Yang Shi Date: Wed, 2 Dec 2020 21:01:12 -0800 Message-ID: Subject: Re: [PATCH 6/9] mm: vmscan: use per memcg nr_deferred of shrinker To: Roman Gushchin Cc: Kirill Tkhai , Shakeel Butt , Dave Chinner , Johannes Weiner , Michal Hocko , Andrew Morton , Linux MM , Linux FS-devel Mailing List , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 2, 2020 at 7:08 PM Roman Gushchin wrote: > > On Wed, Dec 02, 2020 at 10:27:22AM -0800, Yang Shi wrote: > > Use per memcg's nr_deferred for memcg aware shrinkers. The shrinker's nr_deferred > > will be used in the following cases: > > 1. Non memcg aware shrinkers > > 2. !CONFIG_MEMCG > > 3. memcg is disabled by boot parameter > > > > Signed-off-by: Yang Shi > > --- > > mm/vmscan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++---- > > 1 file changed, 82 insertions(+), 6 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index cba0bc8d4661..d569fdcaba79 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -203,6 +203,12 @@ static DECLARE_RWSEM(shrinker_rwsem); > > static DEFINE_IDR(shrinker_idr); > > static int shrinker_nr_max; > > > > +static inline bool is_deferred_memcg_aware(struct shrinker *shrinker) > > +{ > > + return (shrinker->flags & SHRINKER_MEMCG_AWARE) && > > + !mem_cgroup_disabled(); > > +} > > + > > static int prealloc_memcg_shrinker(struct shrinker *shrinker) > > { > > int id, ret = -ENOMEM; > > @@ -271,7 +277,58 @@ static bool writeback_throttling_sane(struct scan_control *sc) > > #endif > > return false; > > } > > + > > +static inline long count_nr_deferred(struct shrinker *shrinker, > > + struct shrink_control *sc) > > +{ > > + bool per_memcg_deferred = is_deferred_memcg_aware(shrinker) && sc->memcg; > > + struct memcg_shrinker_deferred *deferred; > > + struct mem_cgroup *memcg = sc->memcg; > > + int nid = sc->nid; > > + int id = shrinker->id; > > + long nr; > > + > > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > > + nid = 0; > > + > > + if (per_memcg_deferred) { > > + deferred = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_deferred, > > + true); > > + nr = atomic_long_xchg(&deferred->nr_deferred[id], 0); > > + } else > > + nr = atomic_long_xchg(&shrinker->nr_deferred[nid], 0); > > + > > + return nr; > > +} > > + > > +static inline long set_nr_deferred(long nr, struct shrinker *shrinker, > > + struct shrink_control *sc) > > +{ > > + bool per_memcg_deferred = is_deferred_memcg_aware(shrinker) && sc->memcg; > > + struct memcg_shrinker_deferred *deferred; > > + struct mem_cgroup *memcg = sc->memcg; > > + int nid = sc->nid; > > + int id = shrinker->id; > > + long new_nr; > > + > > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > > + nid = 0; > > + > > + if (per_memcg_deferred) { > > + deferred = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_deferred, > > + true); > > + new_nr = atomic_long_add_return(nr, &deferred->nr_deferred[id]); > > + } else > > + new_nr = atomic_long_add_return(nr, &shrinker->nr_deferred[nid]); > > + > > + return new_nr; > > +} > > #else > > +static inline bool is_deferred_memcg_aware(struct shrinker *shrinker) > > +{ > > + return false; > > +} > > + > > static int prealloc_memcg_shrinker(struct shrinker *shrinker) > > { > > return 0; > > @@ -290,6 +347,29 @@ static bool writeback_throttling_sane(struct scan_control *sc) > > { > > return true; > > } > > + > > +static inline long count_nr_deferred(struct shrinker *shrinker, > > + struct shrink_control *sc) > > +{ > > + int nid = sc->nid; > > + > > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > > + nid = 0; > > + > > + return atomic_long_xchg(&shrinker->nr_deferred[nid], 0); > > +} > > + > > +static inline long set_nr_deferred(long nr, struct shrinker *shrinker, > > + struct shrink_control *sc) > > +{ > > + int nid = sc->nid; > > + > > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > > + nid = 0; > > + > > + return atomic_long_add_return(nr, > > + &shrinker->nr_deferred[nid]); > > +} > > #endif > > > > /* > > @@ -429,13 +509,10 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, > > long freeable; > > long nr; > > long new_nr; > > - int nid = shrinkctl->nid; > > long batch_size = shrinker->batch ? shrinker->batch > > : SHRINK_BATCH; > > long scanned = 0, next_deferred; > > > > - if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > > - nid = 0; > > > > freeable = shrinker->count_objects(shrinker, shrinkctl); > > if (freeable == 0 || freeable == SHRINK_EMPTY) > > @@ -446,7 +523,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, > > * and zero it so that other concurrent shrinker invocations > > * don't also do this scanning work. > > */ > > - nr = atomic_long_xchg(&shrinker->nr_deferred[nid], 0); > > + nr = count_nr_deferred(shrinker, shrinkctl); > > > > total_scan = nr; > > if (shrinker->seeks) { > > @@ -539,8 +616,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, > > * move the unused scan count back into the shrinker in a > > * manner that handles concurrent updates. > > */ > > - new_nr = atomic_long_add_return(next_deferred, > > - &shrinker->nr_deferred[nid]); > > + new_nr = set_nr_deferred(next_deferred, shrinker, shrinkctl); > > Ok, I think patch (1) can be just merged into this and then it would make total sense. Sure. Makes sense to me.