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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,PLING_QUERY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 26C94C433E1 for ; Mon, 1 Jun 2020 08:55:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BAD36206C3 for ; Mon, 1 Jun 2020 08:55:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAD36206C3 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 1F2D38E0007; Mon, 1 Jun 2020 04:55:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A3F38E0006; Mon, 1 Jun 2020 04:55:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B8BC8E0007; Mon, 1 Jun 2020 04:55:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0184.hostedemail.com [216.40.44.184]) by kanga.kvack.org (Postfix) with ESMTP id E4A3C8E0006 for ; Mon, 1 Jun 2020 04:55:28 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A5CCD5824 for ; Mon, 1 Jun 2020 08:55:28 +0000 (UTC) X-FDA: 76880034336.29.wheel35_69f650d53ae1c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 87A8A18086E45 for ; Mon, 1 Jun 2020 08:55:28 +0000 (UTC) X-HE-Tag: wheel35_69f650d53ae1c X-Filterd-Recvd-Size: 1572 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 1 Jun 2020 08:55:28 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id DB755AC51; Mon, 1 Jun 2020 08:55:27 +0000 (UTC) Subject: Re: 5.7-rc0: kswapd eats cpu during a disk test?! To: Pavel Machek , kernel list , Andrew Morton Cc: mhocko@suse.cz, "linux-mm@kvack.org" References: <20200531103431.GA28429@amd> From: Vlastimil Babka Message-ID: Date: Mon, 1 Jun 2020 10:55:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200531103431.GA28429@amd> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 87A8A18086E45 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.001208, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: +CC linux-mm On 5/31/20 12:34 PM, Pavel Machek wrote: > Hi! > > This is simple cat /dev/sda > /dev/zero... on thinkpad x60 (x86-32), > with spinning rust. > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 1000 root 20 0 0 0 0 R 53.3 0.0 57:34.93 kswapd0 > 27897 root 20 0 6976 580 536 R 44.5 0.0 1:44.53 cat > > It keeps both CPUs busy... and I don't think that's right. Does an older kernel behave differently here?