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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT 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 261F6C282CE for ; Thu, 23 May 2019 02:28:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CB2B820881 for ; Thu, 23 May 2019 02:28:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB2B820881 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B71666B0003; Wed, 22 May 2019 22:28:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B1E1F6B0006; Wed, 22 May 2019 22:28:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 997BF6B000A; Wed, 22 May 2019 22:28:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ot1-f70.google.com (mail-ot1-f70.google.com [209.85.210.70]) by kanga.kvack.org (Postfix) with ESMTP id 6FFB06B0003 for ; Wed, 22 May 2019 22:28:03 -0400 (EDT) Received: by mail-ot1-f70.google.com with SMTP id n21so2208692otq.16 for ; Wed, 22 May 2019 19:28:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id; bh=fTV9+QJ3Qlr+eWA8hqTAepwEMa3PO/pXGof/Ta/9BdY=; b=lQ7RBjw12gpOvketQBIX1VoFPgRLIciy31Ke+Q/kAoYLxJVyKLjtibHaZEl09vTWnq m7dERu9wcoS/L3zQ19FrzrOgC0KBMFUHgNcFLAcQq+2f46YSFcgL8YUuHGEuwBEPhNcY zMRddksY1CiVZA4zlNL8FCma+RCiVQKX72rvFbMeanpXF4sF3GwcWF1ZxBBztyN2B8QY WfdZxZ3Xn5zXXEdpuUyPZNAUO1d8osQy9cmfDeP6Utr9YmvREgiSxmrzSGBabcMBmyVQ 9L46bjJr+lGyy7i7StllwiMCSUngqDwsWpFQuI8YfUaOJkKlIbXOEUdJ+Qnj5waeGbwH DU2w== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of yang.shi@linux.alibaba.com designates 115.124.30.45 as permitted sender) smtp.mailfrom=yang.shi@linux.alibaba.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alibaba.com X-Gm-Message-State: APjAAAWigepJkCCtObak4tR9NIYwYgXBwCv9H5plamOOSdWuIqTIFmUt FFV/GxTP+pnHXANwXKsAmsIrWea6Hbb9IV1IAo3fPHj1JFc0M3bUy+Dw3DZALiw7mWFH2St77Mo 1ZtRS/j5HwJ8ztu7yZIGYy3AanbqNVxbwGGqHaIGvjcwMfcxP305jLBPJmmhy9ZJ4YQ== X-Received: by 2002:aca:f007:: with SMTP id o7mr1256983oih.59.1558578483099; Wed, 22 May 2019 19:28:03 -0700 (PDT) X-Google-Smtp-Source: APXvYqw1LPpR0uL6WwUfuGpgHxSB4uBSXErmczlUkMR06teM1igg/Br+JEGiTni1UlE/kEaOehXJ X-Received: by 2002:aca:f007:: with SMTP id o7mr1256947oih.59.1558578482104; Wed, 22 May 2019 19:28:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1558578482; cv=none; d=google.com; s=arc-20160816; b=wOp0dBMN7HA40O/KAerferbmtSAOZsV1FM7114zw7r58wpX00EshMJ3XHHmkNDvrNs yG3WUgqFduEFM8QMKSm2StycGeTRwuoAfYOa8xZD9YFp/SCc3ve2WT8E+ydeh5RNsp8z PHXNg0+0SgO0JCErJBsL9jtWxXo8/n5tGgknNmCvdZhYP3AR1hfC+nfYeXLP2zxRYmTl L05tPRBgcu4ctAL3shhF8EJkjP9cwV6FUORssz5Rjjanw0+MQmgIBxoQJMJkmyk8qqL+ 1ttxS6USG4pGWORbcu5pQBXsMDkgxvAMoCvpAEf+Gte7hYWR6OFZBcI7m+QlPBbqAF4m Rfhg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:subject:cc:to:from; bh=fTV9+QJ3Qlr+eWA8hqTAepwEMa3PO/pXGof/Ta/9BdY=; b=AwFknq1/n8Mabl7jwpf6KAC95p/MU8i4tJS3JFBxAUYDipHV4swfcXM5XFOAhhG4o8 PiFloDWsSTdvrD2bC7AZSW0Ruo2V5oNyMle84uln/oYUcJwSjmWaLWoGrsl5vqFkG0bM Gb8KnKjHqWQZfv6pq3wqIQNlWrnbroWL3iNmCFTVYCU69v0GYhYImvBRMOY/2sRCyF1k lWfvNMEHXNp8KzH0zNf9M2nG+Vd6n+gz7zEAcpZG4Gt5MTOvI3TGZ+hGs+17RnqXCO1D 4NuVlXyudc2zX+XN4qQZNfn8dUjtofcpwKK/8IzlmLzwhrgkGNvR2PVBtZ2JMkZRmfB+ g4PA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of yang.shi@linux.alibaba.com designates 115.124.30.45 as permitted sender) smtp.mailfrom=yang.shi@linux.alibaba.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alibaba.com Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com. [115.124.30.45]) by mx.google.com with ESMTPS id k29si15960294otf.306.2019.05.22.19.28.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 May 2019 19:28:02 -0700 (PDT) Received-SPF: pass (google.com: domain of yang.shi@linux.alibaba.com designates 115.124.30.45 as permitted sender) client-ip=115.124.30.45; Authentication-Results: mx.google.com; spf=pass (google.com: domain of yang.shi@linux.alibaba.com designates 115.124.30.45 as permitted sender) smtp.mailfrom=yang.shi@linux.alibaba.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alibaba.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0TSQws5W_1558578458; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TSQws5W_1558578458) by smtp.aliyun-inc.com(127.0.0.1); Thu, 23 May 2019 10:27:45 +0800 From: Yang Shi To: ying.huang@intel.com, hannes@cmpxchg.org, mhocko@suse.com, mgorman@techsingularity.net, kirill.shutemov@linux.intel.com, josef@toxicpanda.com, hughd@google.com, shakeelb@google.com, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [v4 PATCH 1/2] mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned Date: Thu, 23 May 2019 10:27:37 +0800 Message-Id: <1558578458-83807-1-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 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: The commit 9092c71bb724 ("mm: use sc->priority for slab shrink targets") has broken up the relationship between sc->nr_scanned and slab pressure. The sc->nr_scanned can't double slab pressure anymore. So, it sounds no sense to still keep sc->nr_scanned inc'ed. Actually, it would prevent from adding pressure on slab shrink since excessive sc->nr_scanned would prevent from scan->priority raise. The bonnie test doesn't show this would change the behavior of slab shrinkers. w/ w/o /sec %CP /sec %CP Sequential delete: 3960.6 94.6 3997.6 96.2 Random delete: 2518 63.8 2561.6 64.6 The slight increase of "/sec" without the patch would be caused by the slight increase of CPU usage. Cc: Josef Bacik Cc: Michal Hocko Acked-by: Johannes Weiner Signed-off-by: Yang Shi --- v4: Added Johannes's ack mm/vmscan.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7acd0af..b65bc50 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1137,11 +1137,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (!sc->may_unmap && page_mapped(page)) goto keep_locked; - /* Double the slab pressure for mapped and swapcache pages */ - if ((page_mapped(page) || PageSwapCache(page)) && - !(PageAnon(page) && !PageSwapBacked(page))) - sc->nr_scanned++; - may_enter_fs = (sc->gfp_mask & __GFP_FS) || (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO)); -- 1.8.3.1