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 57FACC433EF for ; Wed, 30 Mar 2022 14:22:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9C6E78D0002; Wed, 30 Mar 2022 10:22:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 94F7E8D0001; Wed, 30 Mar 2022 10:22:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7C9BA8D0002; Wed, 30 Mar 2022 10:22:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0231.hostedemail.com [216.40.44.231]) by kanga.kvack.org (Postfix) with ESMTP id 6B10B8D0001 for ; Wed, 30 Mar 2022 10:22:08 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1A27AA4DAC for ; Wed, 30 Mar 2022 14:22:08 +0000 (UTC) X-FDA: 79301267136.23.9565876 Received: from mail-ej1-f41.google.com (mail-ej1-f41.google.com [209.85.218.41]) by imf12.hostedemail.com (Postfix) with ESMTP id B442A40017 for ; Wed, 30 Mar 2022 14:22:07 +0000 (UTC) Received: by mail-ej1-f41.google.com with SMTP id c10so23448671ejs.13 for ; Wed, 30 Mar 2022 07:22:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4iTANxmONAKu4RDVv0y+koCJEtwISqaQFOKub5KCpYY=; b=ARDCeatE6ITj6RrVssEpi4soZXUTx10fHOsOPABcN7zK7iIsBrhSpbv2Mi3z4nezHM XGnjs2pQBWfUgxWDY1Byh5zkoIucQsUZ2Pim338F7IkFcpYpQY5cdrYy8oKnm1UGsXIl /R1JQXydQ6N4QMnX2+PLyOntQjkcwYNpfO/f43dmHUEAMTWp9tZzD4zmrRwFqJXFnDOa 6mnpTxbxUh0DQN6mH1jNcIgCf67RAsDnR4Mbb99c8M/CSvWszvQ5GThgYys4Gh5ndMcd +4B4cLdEnUnPJtoxiYwi3yr28PPlraTvMkSygErs72lyr2tVIz+zI4tjPc1K4anGFQp8 xeyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=4iTANxmONAKu4RDVv0y+koCJEtwISqaQFOKub5KCpYY=; b=SICIsOlw1SFmNPNUjhSq2/EG47QQPwIJkv8pv1QORpOgv3GMjOQv0QNUA6BldIZyp+ I2tqle4+WjIy4H0fa69+HBsyt/Vnzv8Qym3xvbsPsf5UJGgn2Fqno6MF+c+QJzKbjwGr 0QJE7CPUtST6F+rryBGtQbQBsV8qzjEWt6H2Mroo5SIruaOuqzpquQlVp0mSgkdX//7S K6vhLs0vue/T0ohvXVn3PSerm//ZrAUsFdkjPH57MdZppeKYAy4qh8QLgPlRD/aBgu3i AJyb6mfjyZ1gpVqNmjmSXG0KBE4XpstkAXo2hSkTMGYmb3aq0HvWaQ/F9MCSIHgO5GmK JVzw== X-Gm-Message-State: AOAM5331AMpHvYFsJaNh6yPFjuPd1TlPBdmX1fTmYOGAl1cb8QppCYCX qWe7bJg51MXhTDKOb4+LxkU= X-Google-Smtp-Source: ABdhPJzXVCXPTVNzet0Qhi1syNJDEUtoTmJGonpuAY0FK5Rzlw97jdcABj6E3ChkjPw2pSWrLdjJhQ== X-Received: by 2002:a17:907:7f9e:b0:6e0:d34b:7d98 with SMTP id qk30-20020a1709077f9e00b006e0d34b7d98mr25886639ejc.574.1648650126648; Wed, 30 Mar 2022 07:22:06 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id bm23-20020a170906c05700b006d597fd51c6sm8422830ejb.145.2022.03.30.07.22.06 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 30 Mar 2022 07:22:06 -0700 (PDT) Date: Wed, 30 Mar 2022 14:22:05 +0000 From: Wei Yang To: Johannes Weiner Cc: Wei Yang , mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2/3] mm/memcg: set pos to prev unconditionally Message-ID: <20220330142205.iaw6apqxkngp3bdz@master> Reply-To: Wei Yang References: <20220225003437.12620-1-richard.weiyang@gmail.com> <20220225003437.12620-3-richard.weiyang@gmail.com> <20220330004750.fx4jr4bnehz4ynpf@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=ARDCeatE; spf=pass (imf12.hostedemail.com: domain of richard.weiyang@gmail.com designates 209.85.218.41 as permitted sender) smtp.mailfrom=richard.weiyang@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Stat-Signature: 76jqicodhzigp1bqw7dsptwsgiwu9rqt X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: B442A40017 X-HE-Tag: 1648650127-494046 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000186, 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 08:08:49AM -0400, Johannes Weiner wrote: >On Wed, Mar 30, 2022 at 12:47:50AM +0000, Wei Yang wrote: >> Something like this? >> >> 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) > >Yep! Sure, I would prepare a v2. BTW, do you have some comment on patch 3? -- Wei Yang Help you, Help me