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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF498C433EF for ; Fri, 1 Jul 2022 23:09:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 366D16B0073; Fri, 1 Jul 2022 19:09:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3152D6B0074; Fri, 1 Jul 2022 19:09:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 22BC46B0075; Fri, 1 Jul 2022 19:09:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 149746B0073 for ; Fri, 1 Jul 2022 19:09:56 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id DE85C80313 for ; Fri, 1 Jul 2022 23:09:51 +0000 (UTC) X-FDA: 79640075382.23.43183CD Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf14.hostedemail.com (Postfix) with ESMTP id 6CEE5100038 for ; Fri, 1 Jul 2022 23:09:51 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 931FDB80813; Fri, 1 Jul 2022 23:09:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD699C3411E; Fri, 1 Jul 2022 23:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1656716988; bh=4nB0U7nhrm6VCb6tiMM+/XZLx4kueqSVr4+hr+wiTWE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rmqt7SRzy8UX3MGyyYcpwqkGOOwD33znN26rtMMJE+WjxrfG547paZYOkVmgLGK9q TyB8p5PrTf2zhjjJ5CluZBO1gEbEy5bjSrvfrE1fuoPBqUQYBA+TsHzmrG10wW8xM9 Q9oNEUhltPuJzvreon2BKDVDd1L6udVESo8+Wnf4= Date: Fri, 1 Jul 2022 16:09:47 -0700 From: Andrew Morton To: Yosry Ahmed Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Matthew Wilcox , Vlastimil Babka , David Hildenbrand , Miaohe Lin , NeilBrown , Alistair Popple , Suren Baghdasaryan , Peter Xu , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3] mm: vmpressure: don't count proactive reclaim in vmpressure Message-Id: <20220701160947.e4902e5b0484ed084db5d41f@linux-foundation.org> In-Reply-To: <20220630083044.997474-1-yosryahmed@google.com> References: <20220630083044.997474-1-yosryahmed@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1656716991; a=rsa-sha256; cv=none; b=BJl0LRYmuwoO0lxlwvx0pysjm5Xhu+KZmgsOoE9plRuLMAlK41tcBYSU70dSrs6MsP+aix YISPyu9EGZHPl9Z033v6h+NVVKPoEj3fXydG1wWV+EVPa8C0ewVok8hCIj5AQJEMzWpit4 M5GbVuSDa9yDIB+y1ilyv5c4Zjn1bGI= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=rmqt7SRz; dmarc=none; spf=pass (imf14.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1656716991; h=from:from:sender:reply-to:subject:subject: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:dkim-signature; bh=xtlR06cNwYX+/G8nFDae2tvPHLJCLmE6I8r+JtIUpGs=; b=GGTYwkwxKmdX67G3s3RtOa72PZ9xNOHO1exhuYLyweQc7LmsSc7eTVprahHQnjmhEDfsNy jrMayPS4/75DyKcNmEhFP89CN2mPOz2uyIhNcMcDCkw49+Noh1fAGkOSUcyrZfxqI8xEZ5 lk/+4TN2Me6B0s+GzkeQUsNzyuUAFjI= X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 6CEE5100038 Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=rmqt7SRz; dmarc=none; spf=pass (imf14.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspam-User: X-Stat-Signature: 9mtf6g9rpdnmq1dteiyhae5yzz7998tz X-HE-Tag: 1656716991-656071 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 Thu, 30 Jun 2022 08:30:44 +0000 Yosry Ahmed wrote: > vmpressure is used in cgroup v1 to notify userspace of reclaim > efficiency events, and is also used in both cgroup v1 and v2 as a signal > for memory pressure for networking, see > mem_cgroup_under_socket_pressure(). > > Proactive reclaim intends to probe memcgs for cold memory, without > affecting their performance. Hence, reclaim caused by writing to > memory.reclaim should not trigger vmpressure. > > ... > > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2319,6 +2319,7 @@ static unsigned long reclaim_high(struct mem_cgroup *memcg, > gfp_t gfp_mask) > { > unsigned long nr_reclaimed = 0; > + unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; > > do { > unsigned long pflags; > @@ -2331,7 +2332,8 @@ static unsigned long reclaim_high(struct mem_cgroup *memcg, > > psi_memstall_enter(&pflags); > nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, > - gfp_mask, true); > + gfp_mask, > + reclaim_options); It's a bit irksome to create all these unneeded local variables. Why not simply add the constant arg to the try_to_free_mem_cgroup_pages() call? > psi_memstall_leave(&pflags); > } while ((memcg = parent_mem_cgroup(memcg)) && > !mem_cgroup_is_root(memcg)); > @@ -2576,7 +2578,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > struct page_counter *counter; > unsigned long nr_reclaimed; > bool passed_oom = false; > - bool may_swap = true; > + unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; > bool drained = false; > unsigned long pflags; > > @@ -2593,7 +2595,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > mem_over_limit = mem_cgroup_from_counter(counter, memory); > } else { > mem_over_limit = mem_cgroup_from_counter(counter, memsw); > - may_swap = false; > + reclaim_options &= ~MEMCG_RECLAIM_MAY_SWAP; reclaim_options = 0 would be clearer?