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 D6E0BC433FE for ; Thu, 31 Mar 2022 00:21:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 574F86B0072; Wed, 30 Mar 2022 20:21:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5249A6B0073; Wed, 30 Mar 2022 20:21:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3C56B8D0001; Wed, 30 Mar 2022 20:21:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0122.hostedemail.com [216.40.44.122]) by kanga.kvack.org (Postfix) with ESMTP id 2E0466B0072 for ; Wed, 30 Mar 2022 20:21:38 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DA0B6A6319 for ; Thu, 31 Mar 2022 00:21:37 +0000 (UTC) X-FDA: 79302777834.19.8D91F8C Received: from out1.migadu.com (out1.migadu.com [91.121.223.63]) by imf30.hostedemail.com (Postfix) with ESMTP id 3A23680012 for ; Thu, 31 Mar 2022 00:21:37 +0000 (UTC) Date: Wed, 30 Mar 2022 17:21:29 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1648686095; h=from:from:reply-to:subject:subject: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=aWF887DtqFZawSDRTplBMzE6vHE/PS285KJ5U8ZNHwA=; b=KrFNO/YnPGeftymOJt04Ki+/yT0lpAC29OMuRJMM2jNsur/jxiBMNdzjv7iuN1pnC6LllH /BoKRUYj0SF2GnQmz2mH+G0oM5AKaua0UTXmj4MBQN55I8Q3eTLZfaAQbQGJO+Lop5r3q+ zFSYyHGuCgzP+mYixT89TQqAwvXZe98= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Wei Yang Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [Patch v2 2/3] mm/memcg: set pos explicitly for reclaim and !reclaim Message-ID: References: <20220330234719.18340-1-richard.weiyang@gmail.com> <20220330234719.18340-3-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220330234719.18340-3-richard.weiyang@gmail.com> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 3A23680012 X-Stat-Signature: iw6d6ydt1ynndhk6wniekwwrgya63tbd X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="KrFNO/Yn"; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf30.hostedemail.com: domain of roman.gushchin@linux.dev designates 91.121.223.63 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev X-HE-Tag: 1648686097-183593 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, Mar 30, 2022 at 11:47:18PM +0000, Wei Yang wrote: > During mem_cgroup_iter, there are two ways to get iteration position: > reclaim vs non-reclaim mode. > > Let's do it explicitly for reclaim vs non-reclaim mode. > > Signed-off-by: Wei Yang Reviewed-by: Roman Gushchin Thanks! > > --- > v2: split into two explicit part as suggested by Johannes > --- > mm/memcontrol.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index eed9916cdce5..5d433b79ba47 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1005,9 +1005,6 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, > if (!root) > root = root_mem_cgroup; > > - if (prev && !reclaim) > - pos = prev; > - > rcu_read_lock(); > > if (reclaim) { > @@ -1033,6 +1030,8 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, > */ > (void)cmpxchg(&iter->position, pos, NULL); > } > + } else if (prev) { > + pos = prev; > } > > if (pos) > -- > 2.33.1 > >