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=-3.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 105A1C433E2 for ; Wed, 9 Sep 2020 12:11:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8466D2166E for ; Wed, 9 Sep 2020 12:11:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="CrxiqY4e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8466D2166E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bytedance.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B3FB16B005D; Wed, 9 Sep 2020 08:11:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AEF9E6B0075; Wed, 9 Sep 2020 08:11:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B6F06B0078; Wed, 9 Sep 2020 08:11:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id 833B16B005D for ; Wed, 9 Sep 2020 08:11:17 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 3C217180AD811 for ; Wed, 9 Sep 2020 12:11:17 +0000 (UTC) X-FDA: 77243407794.22.honey45_300ae80270dd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id 0EBDF18038E67 for ; Wed, 9 Sep 2020 12:11:17 +0000 (UTC) X-HE-Tag: honey45_300ae80270dd X-Filterd-Recvd-Size: 3819 Received: from mail-pj1-f65.google.com (mail-pj1-f65.google.com [209.85.216.65]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Wed, 9 Sep 2020 12:11:16 +0000 (UTC) Received: by mail-pj1-f65.google.com with SMTP id b16so1241455pjp.0 for ; Wed, 09 Sep 2020 05:11:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3CSI24S8plBTXtRgEcDOdjCLZsD8Xjzm/x3QvW5GzzA=; b=CrxiqY4eqzLovv8Iwz2sAdv/R4dvPyNaEFS0bl0Q+eQt7YSX9DLk69dRuVBaBnrwPC dwVAaK9uxYzBLmAen/KHnYGaWDrzgLDsfx6T4RyahPeFdLRkP2buCCet/pe1TM5R5u2+ qQh+wQMV7HSCveHSET/gSe12NjhmDGKAwhuooc8xiJ/6oCr/2bvkwQ7TIpSpu1fQ9gT3 uBOLib7VicZvdfGzBIFiOEpzy3rFbuaG+lLUIlSPI3Yx0IjLBBXZhziDHGXZgWC/isaM o1HzfXUgWdjlOMoTc6KbAWnC1rcRnvfBQIAgDTG0LxaH/ur8p/t6j4YdTsfDhV8NUT5O gr7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3CSI24S8plBTXtRgEcDOdjCLZsD8Xjzm/x3QvW5GzzA=; b=iPwpyi/csnPUuVKAfn5jEcyH8KZ3oNKZ+4Ka37YOkvmHUE+z/cOXrlGZY+s7knWG0g 01MTpzjPDP6sI4Nho4x08Zfd+lloDQvo4D283EI9Hv4jRzYkPImwm/o5B2qEkKXcK4Xk hoOhpK1QV2IUJ1BZr74UFAwDnkar5qgDSq7/FVAy0ocoGDpN7onpkyQZs2YNwBEGr/4Y xNdd5FE58zod1Ltz+Gyl4cdcmQe22jZXR/NpHEjTHlKdtYoNeF4oJ8V8C4EmSvIzoNrp +0M01KZJvkYO59O8EHeVViw4mQ7MyT99891PewBkq0UdLzbhsa2xISaX1rKGFQ9pU6fS TqlQ== X-Gm-Message-State: AOAM530/lwkNLbgvD7IYCDjUCQ5RC4sY8WGWt1o9nMiD0KzF0AVxSzgd QS9hsnPYiAN4aE/RZTSbZYvm/Rh3VZOcFKuCK/sASQ== X-Google-Smtp-Source: ABdhPJzSzC6P2DfhIWtu+y/IAzCXD0HNAlLfeRfx9UE1/C1qO6I+SsnJZKvhdRFgxyCmlNAKHQM8UXJ8SnF5aucb8yU= X-Received: by 2002:a17:90a:bd0e:: with SMTP id y14mr577786pjr.13.1599653475051; Wed, 09 Sep 2020 05:11:15 -0700 (PDT) MIME-Version: 1.0 References: <20200908142456.89626-1-zangchunxin@bytedance.com> <20200908150945.GA1301981@chrisdown.name> <20200909095915.GA1412646@chrisdown.name> In-Reply-To: <20200909095915.GA1412646@chrisdown.name> From: Muchun Song Date: Wed, 9 Sep 2020 20:10:38 +0800 Message-ID: Subject: Re: [External] Re: [PATCH] mm/vmscan: fix infinite loop in drop_slab_node To: Chris Down Cc: zangchunxin@bytedance.com, Andrew Morton , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 0EBDF18038E67 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Sep 9, 2020 at 5:59 PM Chris Down wrote: > > Muchun Song writes: > >1. Double the threshold currently hard coded as "10" with each iteration > > suggested by Vlastimil. It is also a good idea. > > I think this sounds reasonable, although I'd like to see what the difference in > reclaim looks like in practice. > > >2. In the while loop, we can check whether the TASK_KILLABLE > > signal is set, if so, we should break the loop. like the following code > > snippe. Thanks. > > > >@@ -704,6 +704,9 @@ void drop_slab_node(int nid) > > do { > > struct mem_cgroup *memcg = NULL; > > > >+ if (fatal_signal_pending(current)) > >+ return; > >+ > > freed = 0; > > memcg = mem_cgroup_iter(NULL, NULL, NULL); > > do { > > Regardless of anything, I think this is probably a good idea. Could you send it > as a patch? :-) OK, Will do that thanks. > > Thanks, > > Chris -- Yours, Muchun