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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5D95C32771 for ; Wed, 21 Sep 2022 09:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231246AbiIUJOF (ORCPT ); Wed, 21 Sep 2022 05:14:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231546AbiIUJNj (ORCPT ); Wed, 21 Sep 2022 05:13:39 -0400 Received: from outbound-smtp60.blacknight.com (outbound-smtp60.blacknight.com [46.22.136.244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 489818E9A7 for ; Wed, 21 Sep 2022 02:13:13 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp60.blacknight.com (Postfix) with ESMTPS id 2BB8AFABF8 for ; Wed, 21 Sep 2022 10:13:11 +0100 (IST) Received: (qmail 17661 invoked from network); 21 Sep 2022 09:13:11 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.198.246]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 21 Sep 2022 09:13:10 -0000 Date: Wed, 21 Sep 2022 10:13:03 +0100 From: Mel Gorman To: Hongchen Zhang Cc: Mel Gorman , Matthew Wilcox , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmscan: don't scan adjust too much if current is not kswapd Message-ID: <20220921091303.hihmb3qvfvl3s365@techsingularity.net> References: <20220914023318.549118-1-zhanghongchen@loongson.cn> <20220914155142.bf388515a39fb45bae987231@linux-foundation.org> <6bcb4883-03d0-88eb-4c42-84fff0a9a141@loongson.cn> <54813a74-cc0e-e470-c632-78437a0d0ad4@loongson.cn> <4bd0012e-77ff-9d0d-e295-800471994aeb@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 20, 2022 at 10:23:05AM +0800, Hongchen Zhang wrote: > Hi Mel, > > The scan adjust algorithm was originally introduced by you from > commmit e82e0561dae9 ("mm: vmscan: obey proportional scanning requirements > for kswapd"), any suggestion about this fix patch? > In short, proportional scanning is not friendly to processes other than > kswapd. > I suspect that 6eb90d649537 ("mm: vmscan: fix extreme overreclaim and swap floods") is a more appropriate fix. While it also has a fairness impact, it's a more general approach that is likely more robust and while fairness is important, completely thrashing a full LRU is neither fair nor expected. -- Mel Gorman SUSE Labs