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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 01289C433DB for ; Wed, 17 Feb 2021 06:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A457F64E02 for ; Wed, 17 Feb 2021 06:40:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231580AbhBQGk1 (ORCPT ); Wed, 17 Feb 2021 01:40:27 -0500 Received: from relay.sw.ru ([185.231.240.75]:48710 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231224AbhBQGkS (ORCPT ); Wed, 17 Feb 2021 01:40:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:From: Subject; bh=msbrzWSRT5T++kWmjXz/e9gdzpOs5BdgrXcVbJWD5Xc=; b=tsBHnKGrU+6H/vsSb TAb/c7pIa3s4LaCLiLYIyaITybbHYyf2/5Xu4EgAT93JTIfEAxqjxrul1cIQHZKirvgePPe3ZEAyb gOyb/hyUUiBNjOixs/bDwyIvtJilLiKi3xHQOaS1NQYEGM7Ek59kfb9Hggkl8+cEtCMLG1AkJP6vc =; Received: from [192.168.15.68] by relay.sw.ru with esmtp (Exim 4.94) (envelope-from ) id 1lCGUM-002GTE-8V; Wed, 17 Feb 2021 09:39:06 +0300 Subject: Re: [v8 PATCH 10/13] mm: vmscan: use per memcg nr_deferred of shrinker To: Yang Shi , guro@fb.com, vbabka@suse.cz, shakeelb@google.com, david@fromorbit.com, hannes@cmpxchg.org, mhocko@suse.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210217001322.2226796-1-shy828301@gmail.com> <20210217001322.2226796-11-shy828301@gmail.com> From: Kirill Tkhai Message-ID: Date: Wed, 17 Feb 2021 09:39:15 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210217001322.2226796-11-shy828301@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.02.2021 03:13, 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 Acked-by: Kirill Tkhai > --- > mm/vmscan.c | 78 ++++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 66 insertions(+), 12 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index fcb399e18fc3..57cbc6bc8a49 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -374,6 +374,24 @@ static void unregister_memcg_shrinker(struct shrinker *shrinker) > idr_remove(&shrinker_idr, id); > } > > +static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, > + struct mem_cgroup *memcg) > +{ > + struct shrinker_info *info; > + > + info = shrinker_info_protected(memcg, nid); > + return atomic_long_xchg(&info->nr_deferred[shrinker->id], 0); > +} > + > +static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, > + struct mem_cgroup *memcg) > +{ > + struct shrinker_info *info; > + > + info = shrinker_info_protected(memcg, nid); > + return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); > +} > + > static bool cgroup_reclaim(struct scan_control *sc) > { > return sc->target_mem_cgroup; > @@ -412,6 +430,18 @@ static void unregister_memcg_shrinker(struct shrinker *shrinker) > { > } > > +static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, > + struct mem_cgroup *memcg) > +{ > + return 0; > +} > + > +static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, > + struct mem_cgroup *memcg) > +{ > + return 0; > +} > + > static bool cgroup_reclaim(struct scan_control *sc) > { > return false; > @@ -423,6 +453,39 @@ static bool writeback_throttling_sane(struct scan_control *sc) > } > #endif > > +static long xchg_nr_deferred(struct shrinker *shrinker, > + struct shrink_control *sc) > +{ > + int nid = sc->nid; > + > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > + nid = 0; > + > + if (sc->memcg && > + (shrinker->flags & SHRINKER_MEMCG_AWARE)) > + return xchg_nr_deferred_memcg(nid, shrinker, > + sc->memcg); > + > + return atomic_long_xchg(&shrinker->nr_deferred[nid], 0); > +} > + > + > +static long add_nr_deferred(long nr, struct shrinker *shrinker, > + struct shrink_control *sc) > +{ > + int nid = sc->nid; > + > + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) > + nid = 0; > + > + if (sc->memcg && > + (shrinker->flags & SHRINKER_MEMCG_AWARE)) > + return add_nr_deferred_memcg(nr, nid, shrinker, > + sc->memcg); > + > + return atomic_long_add_return(nr, &shrinker->nr_deferred[nid]); > +} > + > /* > * This misses isolated pages which are not accounted for to save counters. > * As the data only determines if reclaim or compaction continues, it is > @@ -558,14 +621,10 @@ 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) > return freeable; > @@ -575,7 +634,7 @@ 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 = xchg_nr_deferred(shrinker, shrinkctl); > > total_scan = nr; > if (shrinker->seeks) { > @@ -666,14 +725,9 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, > next_deferred = 0; > /* > * move the unused scan count back into the shrinker in a > - * manner that handles concurrent updates. If we exhausted the > - * scan, there is no need to do an update. > + * manner that handles concurrent updates. > */ > - if (next_deferred > 0) > - new_nr = atomic_long_add_return(next_deferred, > - &shrinker->nr_deferred[nid]); > - else > - new_nr = atomic_long_read(&shrinker->nr_deferred[nid]); > + new_nr = add_nr_deferred(next_deferred, shrinker, shrinkctl); > > trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan); > return freed; >