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 89286C4332F for ; Sat, 12 Nov 2022 14:23:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233989AbiKLOXo (ORCPT ); Sat, 12 Nov 2022 09:23:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230170AbiKLOXl (ORCPT ); Sat, 12 Nov 2022 09:23:41 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D88F7CE0A for ; Sat, 12 Nov 2022 06:23:39 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id 4so6488542pli.0 for ; Sat, 12 Nov 2022 06:23:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=9AaCZ8WAfpjeSDQ7STKLSNV9+Kr6/3hjw3GaFvuUHO4=; b=w+EQNfOU9HvsctHMxKfjHvI6LHdBV+tXm3jN/4uj+p7uD59lDpfryM+Xs11aiD5uip 4FkecEfcnWf2m/0QzgI05iqydkRLfZhU72lgKlW7fXNt4ZGg9DZ6Anaa1FvodTNwbzPg p297axSGKmM5lYQvMCmjaPhROs+IGp/WT4/Ls/ZP0ETAiiW4ApKmEjsgjg4JQ9h/GNP4 3XtyjXZQ0V+DMQ3BP+OkLbjZxxePgTFGb8kdbSAWAWlY59+1WhoP+k887Xy4T9ET0sqN Dz6Whq16emyyXY+FVFz16u6BG+KMo4nq6RSLSsTn6Cruio/gtqKsess+0G519p1S+cjV 8izg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=9AaCZ8WAfpjeSDQ7STKLSNV9+Kr6/3hjw3GaFvuUHO4=; b=dw6inSxlfte4/8gIU5Jrva/skW18dYBbzbI4nJNfBGOizeYm8BHGRLN66cx1Vk65qe fYbFZJ0sEwotVhkWeprsjStAnAZ2aq9JmkdPvoiuxTHiDDHxtMHMkw5JUGX+YpTyMhbO OeBIlFAY15sCwsfEqrX/tzsSTMuyQqF1IObgglZO5MobEPOV0gvECjlenG9XmVSF/1OE 0L0KIbulDLYp6k6+xGf6vO14InNRVRwFKCopxrgn01ddIIoAO26EOBtNNttGO/r1lETW 1klRQ+b34/1XYPEeFkxBbBJmOr/qWMXqO/Fb3jHQzTe9W2CJhLxhwQpALZJQeByyXvGc QxIg== X-Gm-Message-State: ANoB5pnjE3PoCUhyxeEhlqdFA+/4zkDko68D2DVkp8390lt3Yx1dH68A 7RS5m2EP7VLKt6E6IisgAkyXTw== X-Google-Smtp-Source: AA0mqf7Of4uNO9Zacj/tIazdwCiwUWGFkPYUXSHNE53CmPX12vcNQJGoCT8F+yXOQVOlrPeOP1xXHA== X-Received: by 2002:a17:902:c142:b0:188:55f5:972f with SMTP id 2-20020a170902c14200b0018855f5972fmr6969764plj.148.1668263019381; Sat, 12 Nov 2022 06:23:39 -0800 (PST) Received: from localhost ([2620:10d:c090:400::5:54c6]) by smtp.gmail.com with ESMTPSA id u2-20020a170902714200b00185402cfedesm3681172plm.246.2022.11.12.06.23.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Nov 2022 06:23:38 -0800 (PST) Date: Sat, 12 Nov 2022 09:23:41 -0500 From: Johannes Weiner To: Hongchen Zhang Cc: Andrew Morton , Mel Gorman , Hugh Dickins , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Yosry Ahmed Subject: Re: [PATCH] mm: vmscan: fix extreme overreclaim and swap floods Message-ID: References: <20220802162811.39216-1-hannes@cmpxchg.org> <17f04d65-020e-a52d-41e8-0d540e32b475@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <17f04d65-020e-a52d-41e8-0d540e32b475@loongson.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 20, 2022 at 02:12:17PM +0800, Hongchen Zhang wrote: > On 2022/8/3 am 12:28, Johannes Weiner wrote: > > @@ -2988,8 +2988,6 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) > > nr_scanned = targets[lru] - nr[lru]; > > nr[lru] = targets[lru] * (100 - percentage) / 100; > > nr[lru] -= min(nr[lru], nr_scanned); > We should not just remove the following line because kswapd may also call > this function and there is no side effect to do scan adjust for kswapd,so it > may be better to change like this: > + if (current_is_kswapd()) > scan_adjusted = true; > > - > > - scan_adjusted = true There is no scan_adjusted after this patch. If you're saying that kswapd should set proportional_reclaim unconditionally, then no, it should not. Proportional reclaim is not safe at lower priority levels, as the changelog outlines in detail.