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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE52CC433EF for ; Thu, 25 Nov 2021 03:31:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1A94F6B0074; Wed, 24 Nov 2021 22:31:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 157DF6B0075; Wed, 24 Nov 2021 22:31:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0201C6B007B; Wed, 24 Nov 2021 22:31:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0110.hostedemail.com [216.40.44.110]) by kanga.kvack.org (Postfix) with ESMTP id E3A3B6B0074 for ; Wed, 24 Nov 2021 22:31:00 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 93ABF818A07A for ; Thu, 25 Nov 2021 03:30:50 +0000 (UTC) X-FDA: 78846025860.03.569F84A Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf27.hostedemail.com (Postfix) with ESMTP id 88C0B70000B6 for ; Thu, 25 Nov 2021 03:30:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=FJveyksDdIzezjLTh+rtqlw7W3mbjgrzS1zYLwDdyJw=; b=Vj1482sPd6MjdEtA4qCXvJvQgD WL8f/9idar4o0C/fULR3TZDxRtRNJMjmdXZyjO9qAMmUE6otb1jbAdlCat9KaXunIf3DoF/4SaiZo d70wYXABjupPPwTtTdu75c8n0aotcx9CFFrEmcXXFx33d6XSaX9SGWn6mkRv/yzmbEazqSowyQ5Jo ckv/+EaPXkcil4YJKlFWKRCpI3R0DFuCkatvSXzBb/qo3VzEipuSAbPba2decKg5GjX+JFvzCjY13 8p0AYV+r1HdmRsCiFTBSXCLS4PaiyPOcWpuXgoEE0IQiFcnx9fm/vlOmtFRpBd+J89SK2FZJvTXlK r0s68t0Q==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mq5TA-004ZXE-H4; Thu, 25 Nov 2021 03:30:44 +0000 Date: Thu, 25 Nov 2021 03:30:44 +0000 From: Matthew Wilcox To: Hao Lee Cc: Michal Hocko , Linux MM , Johannes Weiner , vdavydov.dev@gmail.com, Shakeel Butt , cgroups@vger.kernel.org, LKML Subject: Re: [PATCH] mm: reduce spinlock contention in release_pages() Message-ID: References: <20211124151915.GA6163@haolee.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 88C0B70000B6 X-Stat-Signature: mid95fmozgh3z5adrs9s7gf1w6i6eziq Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Vj1482sP; dmarc=none; spf=none (imf27.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-HE-Tag: 1637811048-256126 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000009, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Nov 25, 2021 at 11:24:02AM +0800, Hao Lee wrote: > On Thu, Nov 25, 2021 at 12:31 AM Michal Hocko wrote: > > We do batch currently so no single task should be > > able to monopolize the cpu for too long. Why this is not sufficient? > > uncharge and unref indeed take advantage of the batch process, but > del_from_lru needs more time to complete. Several tasks will contend > spinlock in the loop if nr is very large. Is SWAP_CLUSTER_MAX too large? Or does your architecture's spinlock implementation need to be fixed?