From patchwork Mon Feb 28 12:21:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12763156 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC179C4332F for ; Mon, 28 Feb 2022 12:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236362AbiB1MYq (ORCPT ); Mon, 28 Feb 2022 07:24:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236377AbiB1MYQ (ORCPT ); Mon, 28 Feb 2022 07:24:16 -0500 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F8F87487F for ; Mon, 28 Feb 2022 04:23:34 -0800 (PST) Received: by mail-pg1-x52b.google.com with SMTP id c1so11206309pgk.11 for ; Mon, 28 Feb 2022 04:23:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4weE4kqhVNNelpninfKVs0Z5lAWaMF5vJ9tpJi1vKqM=; b=jNIurO4J5jzzg6tw4FkyFriQIvcP76IRCFSaYIPHcK6WypzpBeQpxT2wVTd235Rx+H zIM3T3a8rwrhBykl8ohYk5Rc989WTu+s+jPwkike3SU1b3etv0KAPcS0b4SrXMmRau5V 0XbYaQddQw2cwYkWhjXYHjmGO10fEHgAzCMhMqJ2gkZ3249Xgb3P6nEgYgKIL7C8Fduc PlmhdyUHJ1/oOtXztvv1x2qiybg82kKYTC7ZYo3Wp4hJOrsH08TwJq1UFHRkMxviVlee kHCyRPQBH+81w9gv77XtRh/AUjRq2gsCar9rXwYlvYrfL/BuBWxcTVZaCJTztmsk1L4F 5z6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4weE4kqhVNNelpninfKVs0Z5lAWaMF5vJ9tpJi1vKqM=; b=bvY1cBxPkbVOcJn8P86D7xMnVMrbyMN1BI+EmQSbeUH51l+1++P9JG/zSPnAc2bZRv UdbbqBC+Qji5VdZHGeTlNpvUgGRaeISUuaQEqPjabMFP9luJx9+nhqq61U3ib1YvgmmV TtQ/OKvrN7+9TchGXI2wHD0LRaMwOs9gVgNPBNCN8apOpe7Oqn0zOJDowuucPJ6y744r UjymlgBKaVClUDEgirT52QknRIAvX+sJWgYzG4G9fSEXJvSqOdk9QLbEmWDDcs1dCk3w 6hn7W6QX7787Gz43V+G7U3vTzcOWH/OXGSe4oUIjV8jlQNyC3gU2MUKfMJ+Fh5rDRsDR 9dig== X-Gm-Message-State: AOAM533iKGwpdw/r5pRwc5revhY+Nik007iP4Hi1unFBsaScpzqEh1Qu +c/OnOxXWzOuAyCktrw/qDfVIw== X-Google-Smtp-Source: ABdhPJy0Y3sz8zYIu7FfTE85icoaySMSdHhDkvZcfxDVS79w35TAOVMTZcKVPjThbCUvuMwVu0O9uQ== X-Received: by 2002:a65:554e:0:b0:34d:f721:7fef with SMTP id t14-20020a65554e000000b0034df7217fefmr7749911pgr.476.1646051013796; Mon, 28 Feb 2022 04:23:33 -0800 (PST) Received: from FVFYT0MHHV2J.tiktokcdn.com ([139.177.225.227]) by smtp.gmail.com with ESMTPSA id ep22-20020a17090ae65600b001b92477db10sm10466753pjb.29.2022.02.28.04.23.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Feb 2022 04:23:33 -0800 (PST) From: Muchun Song To: willy@infradead.org, akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, shakeelb@google.com, roman.gushchin@linux.dev, shy828301@gmail.com, alexs@kernel.org, richard.weiyang@gmail.com, david@fromorbit.com, trond.myklebust@hammerspace.com, anna.schumaker@netapp.com, jaegeuk@kernel.org, chao@kernel.org, kari.argillander@gmail.com, vbabka@suse.cz Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, zhengqi.arch@bytedance.com, duanxiongchun@bytedance.com, fam.zheng@bytedance.com, smuchun@gmail.com, Muchun Song Subject: [PATCH v6 09/16] mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() Date: Mon, 28 Feb 2022 20:21:19 +0800 Message-Id: <20220228122126.37293-10-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220228122126.37293-1-songmuchun@bytedance.com> References: <20220228122126.37293-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org It will simplify the code if moving memcg_online_kmem() to mem_cgroup_css_online() and do not need to set ->kmemcg_id to -1 to indicate the memcg is offline. In the next patch, ->kmemcg_id will be used to sync list lru reparenting which requires not to change ->kmemcg_id. Signed-off-by: Muchun Song Acked-by: Roman Gushchin --- mm/memcontrol.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ffc5f0798de1..5bdf5184681c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3616,7 +3616,8 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) if (cgroup_memory_nokmem) return 0; - BUG_ON(memcg->kmemcg_id >= 0); + if (unlikely(mem_cgroup_is_root(memcg))) + return 0; memcg_id = memcg_alloc_cache_id(); if (memcg_id < 0) @@ -3642,7 +3643,10 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) struct mem_cgroup *parent; int kmemcg_id; - if (memcg->kmemcg_id == -1) + if (cgroup_memory_nokmem) + return; + + if (unlikely(mem_cgroup_is_root(memcg))) return; parent = parent_mem_cgroup(memcg); @@ -3652,7 +3656,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) memcg_reparent_objcgs(memcg, parent); kmemcg_id = memcg->kmemcg_id; - BUG_ON(kmemcg_id < 0); /* * After we have finished memcg_reparent_objcgs(), all list_lrus @@ -3663,7 +3666,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) memcg_drain_all_list_lrus(kmemcg_id, parent); memcg_free_cache_id(kmemcg_id); - memcg->kmemcg_id = -1; } #else static int memcg_online_kmem(struct mem_cgroup *memcg) @@ -5178,7 +5180,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); struct mem_cgroup *memcg, *old_memcg; - long error = -ENOMEM; old_memcg = set_active_memcg(parent); memcg = mem_cgroup_alloc(); @@ -5207,34 +5208,26 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) return &memcg->css; } - /* The following stuff does not apply to the root */ - error = memcg_online_kmem(memcg); - if (error) - goto fail; - if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_inc(&memcg_sockets_enabled_key); return &memcg->css; -fail: - mem_cgroup_id_remove(memcg); - mem_cgroup_free(memcg); - return ERR_PTR(error); } static int mem_cgroup_css_online(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + if (memcg_online_kmem(memcg)) + goto remove_id; + /* * A memcg must be visible for expand_shrinker_info() * by the time the maps are allocated. So, we allocate maps * here, when for_each_mem_cgroup() can't skip it. */ - if (alloc_shrinker_info(memcg)) { - mem_cgroup_id_remove(memcg); - return -ENOMEM; - } + if (alloc_shrinker_info(memcg)) + goto offline_kmem; /* Online state pins memcg ID, memcg ID pins CSS */ refcount_set(&memcg->id.ref, 1); @@ -5244,6 +5237,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) queue_delayed_work(system_unbound_wq, &stats_flush_dwork, 2UL*HZ); return 0; +offline_kmem: + memcg_offline_kmem(memcg); +remove_id: + mem_cgroup_id_remove(memcg); + return -ENOMEM; } static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) @@ -5301,9 +5299,6 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) cancel_work_sync(&memcg->high_work); mem_cgroup_remove_from_trees(memcg); free_shrinker_info(memcg); - - /* Need to offline kmem if online_css() fails */ - memcg_offline_kmem(memcg); mem_cgroup_free(memcg); }