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=-0.7 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 E67E6CA9EAE for ; Tue, 29 Oct 2019 12:31:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 949A821479 for ; Tue, 29 Oct 2019 12:31:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 949A821479 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 428086B0005; Tue, 29 Oct 2019 08:31:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D88B6B0006; Tue, 29 Oct 2019 08:31:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2EE306B0007; Tue, 29 Oct 2019 08:31:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0080.hostedemail.com [216.40.44.80]) by kanga.kvack.org (Postfix) with ESMTP id 0238F6B0005 for ; Tue, 29 Oct 2019 08:31:15 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id ABA0F7591 for ; Tue, 29 Oct 2019 12:31:15 +0000 (UTC) X-FDA: 76096757310.08.bike38_27e87b1ef7011 X-HE-Tag: bike38_27e87b1ef7011 X-Filterd-Recvd-Size: 2004 Received: from mail3-163.sinamail.sina.com.cn (mail3-163.sinamail.sina.com.cn [202.108.3.163]) by imf12.hostedemail.com (Postfix) with SMTP for ; Tue, 29 Oct 2019 12:31:13 +0000 (UTC) Received: from unknown (HELO localhost.localdomain)([222.131.69.34]) by sina.com with ESMTP id 5DB8310D00001F61; Tue, 29 Oct 2019 20:31:11 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 16227649284401 From: Hillf Danton To: Michal Hocko Cc: Hillf Danton , linux-mm , Andrew Morton , linux-kernel , Matthew Wilcox , Johannes Weiner , Shakeel Butt , Minchan Kim , Mel Gorman , Vladimir Davydov , Jan Kara Subject: Re: [RFC v2] mm: add page preemption Date: Tue, 29 Oct 2019 20:30:58 +0800 Message-Id: <20191029123058.19060-1-hdanton@sina.com> In-Reply-To: <20191026112808.14268-1-hdanton@sina.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.005965, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Date: Tue, 29 Oct 2019 09:41:53 +0100 Michal Hocko wrote: >=20 > As already raised in the review of v1. There is no real life usecase > described in the changelog. No feature, no user; no user, no workloads. No linux-6.x released, no 6.x users. Are you going to be one of the users of linux-6.0? Even though, I see a use case over there at https://lore.kernel.org/lkml/20191023120452.GN754@dhcp22.suse.cz/ That thread terminated because of preemption, showing us how useful preemption might be in real life. > I have also expressed concerns about how > such a reclaim would work in the first place Based on what? > (priority inversion, No prio inversion will happen after introducing prio to global reclaim. > expensive reclaim etc.). No cost, no earn.