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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB589C433EF for ; Wed, 20 Oct 2021 08:55:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 766DB611EF for ; Wed, 20 Oct 2021 08:55:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 766DB611EF Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 126CE900002; Wed, 20 Oct 2021 04:55:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D5F36B0072; Wed, 20 Oct 2021 04:55:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F069D900002; Wed, 20 Oct 2021 04:55:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0066.hostedemail.com [216.40.44.66]) by kanga.kvack.org (Postfix) with ESMTP id DCE1E6B0071 for ; Wed, 20 Oct 2021 04:55:29 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 91A4E181AF5C6 for ; Wed, 20 Oct 2021 08:55:29 +0000 (UTC) X-FDA: 78716207178.35.22A601F Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf19.hostedemail.com (Postfix) with ESMTP id 5C218B0000A2 for ; Wed, 20 Oct 2021 08:55:26 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id EFF902195C; Wed, 20 Oct 2021 08:55:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1634720127; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=drSdqOUgPDLzIHMDdiQEpBl1jbGldtxzCXUREGTCpAM=; b=u6aivwsI93BOLQ2BzXCgWIomMSDlUSdi3jJ0dPetefXsuaecwNvzbFyEFtsbnKv2NzpK9R 5dKlih6TC9wCQ3gvT2070HjuklrmgnYWcbLqBVGB8EnU9rrdnQ8c+gPbzITYF91aW8ig0Y AIyAKqCKtlWbBVflVmXRWGEBwTrxkuk= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 8F892A3C33; Wed, 20 Oct 2021 08:55:27 +0000 (UTC) Date: Wed, 20 Oct 2021 10:55:27 +0200 From: Michal Hocko To: Zhaoyang Huang Cc: Andrew Morton , Johannes Weiner , Vladimir Davydov , Zhaoyang Huang , "open list:MEMORY MANAGEMENT" , LKML Subject: Re: [PATCH] mm: skip current when memcg reclaim Message-ID: References: <1634278529-16983-1-git-send-email-huangzhaoyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=u6aivwsI; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf19.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 5C218B0000A2 X-Stat-Signature: 8d4nkzh4rgdcyeh8gn3idfix36duojfa X-HE-Tag: 1634720126-793986 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 20-10-21 15:33:39, Zhaoyang Huang wrote: [...] > Do you mean that direct reclaim should succeed for the first round > reclaim within which memcg get protected by memory.low and would NOT > retry by setting memcg_low_reclaim to true? Yes, this is the semantic of low limit protection in the upstream kernel. Have a look at do_try_to_free_pages and how it sets memcg_low_reclaim only if there were no pages reclaimed. > It is not true in android > like system, where reclaim always failed and introduce lmk and even > OOM. I am not familiar with android specific changes to the upstream reclaim logic. You should be investigating why the reclaim couldn't make a forward progress (aka reclaim pages) from non-protected memcgs. There are tracepoints you can use (generally vmscan prefix). -- Michal Hocko SUSE Labs