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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C6C5FC433DB for ; Fri, 29 Jan 2021 15:13:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5F07564E05 for ; Fri, 29 Jan 2021 15:13:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F07564E05 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 71AE86B0006; Fri, 29 Jan 2021 10:13:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6CBAC6B0070; Fri, 29 Jan 2021 10:13:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5BA656B0071; Fri, 29 Jan 2021 10:13:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 45E086B0006 for ; Fri, 29 Jan 2021 10:13:45 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 08281824999B for ; Fri, 29 Jan 2021 15:13:45 +0000 (UTC) X-FDA: 77759157210.30.start26_1b04624275a9 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 89E42180B3C8B for ; Fri, 29 Jan 2021 15:13:44 +0000 (UTC) X-HE-Tag: start26_1b04624275a9 X-Filterd-Recvd-Size: 2621 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Fri, 29 Jan 2021 15:13:44 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A2211AFF9; Fri, 29 Jan 2021 15:13:42 +0000 (UTC) Subject: Re: [v5 PATCH 08/11] mm: vmscan: use per memcg nr_deferred of shrinker To: Yang Shi , guro@fb.com, ktkhai@virtuozzo.com, 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: <20210127233345.339910-1-shy828301@gmail.com> <20210127233345.339910-9-shy828301@gmail.com> From: Vlastimil Babka Message-ID: Date: Fri, 29 Jan 2021 16:13:42 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210127233345.339910-9-shy828301@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 1/28/21 12:33 AM, 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 | 87 ++++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 73 insertions(+), 14 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 20be0db291fe..e1f8960f5cf6 100644 ... > @@ -653,14 +717,9 @@ 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]); Why not keep this write avoidance if next_deferred == 0 in the new helper? > + new_nr = set_nr_deferred(next_deferred, shrinker, shrinkctl); > > trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan); > return freed; >