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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 B6E02C73C7C for ; Wed, 10 Jul 2019 11:16:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E90B2084B for ; Wed, 10 Jul 2019 11:16:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562757386; bh=RGD/vidgsDuU7NFtcLeQfp/bwEy6DU9dIgAurbz4NUo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=gCmhOu0Z27MRfuPACk+9KBRhXbEonYx1DRqa1xJx6ma5/zviXQFoYWjZ6QfPnu/su ZV90MkqguwP9aaVzlHMzLfnxCDkFWWMlgiUbSBD3ZeaScmIZuDgaSA17vRSRzH5dWz KCv/nkHsn+fjkyb+qdmrqD+CEhxhJttHt/1Gl4uE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727110AbfGJLQZ (ORCPT ); Wed, 10 Jul 2019 07:16:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:48668 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726097AbfGJLQY (ORCPT ); Wed, 10 Jul 2019 07:16:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 601B4AF05; Wed, 10 Jul 2019 11:16:23 +0000 (UTC) Date: Wed, 10 Jul 2019 13:16:22 +0200 From: Michal Hocko To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , linux-api@vger.kernel.org, Johannes Weiner , Tim Murray , Joel Fernandes , Suren Baghdasaryan , Daniel Colascione , Shakeel Butt , Sonny Rao , oleksandr@redhat.com, hdanton@sina.com, lizeb@google.com, Dave Hansen , "Kirill A . Shutemov" Subject: Re: [PATCH v3 4/5] mm: introduce MADV_PAGEOUT Message-ID: <20190710111622.GI29695@dhcp22.suse.cz> References: <20190627115405.255259-1-minchan@kernel.org> <20190627115405.255259-5-minchan@kernel.org> <20190709095518.GF26380@dhcp22.suse.cz> <20190710104809.GA186559@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190710104809.GA186559@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 10-07-19 19:48:09, Minchan Kim wrote: > On Tue, Jul 09, 2019 at 11:55:19AM +0200, Michal Hocko wrote: [...] > > I am still not convinced about the SWAP_CLUSTER_MAX batching and the > > udnerlying OOM argument. Is one pmd worth of pages really an OOM risk? > > Sure you can have many invocations in parallel and that would add on > > but the same might happen with SWAP_CLUSTER_MAX. So I would just remove > > the batching for now and think of it only if we really see this being a > > problem for real. Unless you feel really strong about this, of course. > > I don't have the number to support SWAP_CLUSTER_MAX batching for hinting > operations. However, I wanted to be consistent with other LRU batching > logic so that it could affect altogether if someone try to increase > SWAP_CLUSTER_MAX which is more efficienty for batching operation, later. > (AFAIK, someone tried it a few years ago but rollback soon, I couldn't > rebemeber what was the reason at that time, anyway). Then please drop this part. It makes the code more complex while any benefit is not demonstrated. > > Anyway the patch looks ok to me otherwise. > > > > Acked-by: Michal Hocko > > Thanks! -- Michal Hocko SUSE Labs