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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 8053CC43381 for ; Mon, 18 Feb 2019 13:49:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 507BA21904 for ; Mon, 18 Feb 2019 13:49:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497750; bh=asEn45jtNeeGS//njbzhj5/xTE1LJZDha6CXgMrElTE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=P2VzqJXSQifptuP9tPPhf8uoj8KiUeutlovAkld4jdNbSExiSWdh3IleTie7vls6D cYxQSJUh17vesPCONN1stvEaOdGNmKwWCJQBQC8L1aowzzEdCO0UEI6hY8jMX5yjI0 ySKxeva8xeqv+U7cd+SsAjrlTdou54WoI/fqmcZY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731509AbfBRNtJ (ORCPT ); Mon, 18 Feb 2019 08:49:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:56198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731960AbfBRNtG (ORCPT ); Mon, 18 Feb 2019 08:49:06 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0A63020449; Mon, 18 Feb 2019 13:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497745; bh=asEn45jtNeeGS//njbzhj5/xTE1LJZDha6CXgMrElTE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mLO/WcTmQB1SUBWR4KvKQtTalutcTBzkXQG4TeYuvc+eNtv/IlKkwkzPhD9KUkajM UN4kparyIa4z7xHw4AQgD9yC8DPKa1FRoaNjpBqVogdsOKS75ABGCRFzvpyAFjGyKt EFyHIKHusMoeArNCdhw48/GT6LI8S7hp87uT6P9o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Chinner , Wolfgang Walter , Roman Gushchin , Spock , Rik van Riel , Michal Hocko , Andrew Morton , Linus Torvalds Subject: [PATCH 4.20 71/92] Revert "mm: slowly shrink slabs with a relatively small number of objects" Date: Mon, 18 Feb 2019 14:43:14 +0100 Message-Id: <20190218133501.533140116@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218133454.668268457@linuxfoundation.org> References: <20190218133454.668268457@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Chinner commit a9a238e83fbb0df31c3b9b67003f8f9d1d1b6c96 upstream. This reverts commit 172b06c32b9497 ("mm: slowly shrink slabs with a relatively small number of objects"). This change changes the agressiveness of shrinker reclaim, causing small cache and low priority reclaim to greatly increase scanning pressure on small caches. As a result, light memory pressure has a disproportionate affect on small caches, and causes large caches to be reclaimed much faster than previously. As a result, it greatly perturbs the delicate balance of the VFS caches (dentry/inode vs file page cache) such that the inode/dentry caches are reclaimed much, much faster than the page cache and this drives us into several other caching imbalance related problems. As such, this is a bad change and needs to be reverted. [ Needs some massaging to retain the later seekless shrinker modifications.] Link: http://lkml.kernel.org/r/20190130041707.27750-3-david@fromorbit.com Fixes: 172b06c32b9497 ("mm: slowly shrink slabs with a relatively small number of objects") Signed-off-by: Dave Chinner Cc: Wolfgang Walter Cc: Roman Gushchin Cc: Spock Cc: Rik van Riel Cc: Michal Hocko Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/vmscan.c | 10 ---------- 1 file changed, 10 deletions(-) --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -487,16 +487,6 @@ static unsigned long do_shrink_slab(stru delta = freeable / 2; } - /* - * Make sure we apply some minimal pressure on default priority - * even on small cgroups. Stale objects are not only consuming memory - * by themselves, but can also hold a reference to a dying cgroup, - * preventing it from being reclaimed. A dying cgroup with all - * corresponding structures like per-cpu stats and kmem caches - * can be really big, so it may lead to a significant waste of memory. - */ - delta = max_t(unsigned long long, delta, min(freeable, batch_size)); - total_scan += delta; if (total_scan < 0) { pr_err("shrink_slab: %pF negative objects to delete nr=%ld\n",