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 4624DC433EF for ; Thu, 14 Oct 2021 12:31:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B6423610F9 for ; Thu, 14 Oct 2021 12:31:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B6423610F9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 29B956B006C; Thu, 14 Oct 2021 08:31:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 224BE6B0071; Thu, 14 Oct 2021 08:31:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C614900002; Thu, 14 Oct 2021 08:31:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0114.hostedemail.com [216.40.44.114]) by kanga.kvack.org (Postfix) with ESMTP id ED76B6B006C for ; Thu, 14 Oct 2021 08:31:19 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A83678249980 for ; Thu, 14 Oct 2021 12:31:19 +0000 (UTC) X-FDA: 78694978278.03.6862546 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf16.hostedemail.com (Postfix) with ESMTP id 6F37FF00008E for ; Thu, 14 Oct 2021 12:31:18 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BB88521981; Thu, 14 Oct 2021 12:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1634214677; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n40SRtgva50SSKl6eT8u22z5biYkfXHzvY/Tg6OKccQ=; b=0ls32B682t/neYUSNUr8zXQaacQZqKZclL6GE6565/a7AZ/+/wk6Q+tpohi0dcJgezb5Fd 36rHePtmN0c+xr1bj8a9L6Yf2JvYQRpDOiOB3B4bCzoqmvoK8kP1vG9yKHHfDa+xd3oQ9P ozwK3bq895bxNgnb/Qvfg9RYADmfDGM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1634214677; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n40SRtgva50SSKl6eT8u22z5biYkfXHzvY/Tg6OKccQ=; b=SiaZeAb3Bsc9kDNRP0Y09OL70P79ppmR7mpZvUOqQsqET3kSk537ChPFTjmYmuifeMQDrm 2ORISegYfQ1aMNDA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 8707E13D8A; Thu, 14 Oct 2021 12:31:17 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id SYk+IBUjaGFLPwAAMHmgww (envelope-from ); Thu, 14 Oct 2021 12:31:17 +0000 Message-ID: <63336163-e709-65de-6d53-8764facd3924@suse.cz> Date: Thu, 14 Oct 2021 14:31:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Content-Language: en-US To: Mel Gorman , Linux-MM Cc: NeilBrown , Theodore Ts'o , Andreas Dilger , "Darrick J . Wong" , Matthew Wilcox , Michal Hocko , Dave Chinner , Rik van Riel , Johannes Weiner , Jonathan Corbet , Linux-fsdevel , LKML References: <20211008135332.19567-1-mgorman@techsingularity.net> <20211008135332.19567-4-mgorman@techsingularity.net> From: Vlastimil Babka In-Reply-To: <20211008135332.19567-4-mgorman@techsingularity.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 6F37FF00008E X-Stat-Signature: 1wucb8dadoef33q9kpmacq87ihsx7i5a Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=0ls32B68; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=SiaZeAb3; spf=pass (imf16.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none X-HE-Tag: 1634214678-593304 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 10/8/21 15:53, Mel Gorman wrote: > Memcg reclaim throttles on congestion if no reclaim progress is made. > This makes little sense, it might be due to writeback or a host of > other factors. > > For !memcg reclaim, it's messy. Direct reclaim primarily is throttled > in the page allocator if it is failing to make progress. Kswapd > throttles if too many pages are under writeback and marked for > immediate reclaim. > > This patch explicitly throttles if reclaim is failing to make progress. > > Signed-off-by: Mel Gorman ... > @@ -3769,6 +3797,16 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, > trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed); > set_task_reclaim_state(current, NULL); > > + if (!nr_reclaimed) { > + struct zoneref *z; > + pg_data_t *pgdat; > + > + z = first_zones_zonelist(zonelist, sc.reclaim_idx, sc.nodemask); > + pgdat = zonelist_zone(z)->zone_pgdat; > + > + reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS, HZ/10); > + } Is this necessary? AFAICS here we just returned from: do_try_to_free_pages() shrink_zones() for_each_zone()... consider_reclaim_throttle() Which already throttles when needed and using the appropriate pgdat, while here we have to somewhat awkwardly assume the preferred one. > + > return nr_reclaimed; > } > #endif >