From patchwork Tue May 24 06:05:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12859711 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 24375C433EF for ; Tue, 24 May 2022 06:27:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BD7BA6B0074; Tue, 24 May 2022 02:27:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B63B36B007D; Tue, 24 May 2022 02:27:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A2A7F8D0001; Tue, 24 May 2022 02:27:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 945E86B007D for ; Tue, 24 May 2022 02:27:58 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 63824612F6 for ; Tue, 24 May 2022 06:27:58 +0000 (UTC) X-FDA: 79499656236.27.013C380 Received: from mail-pg1-f180.google.com (mail-pg1-f180.google.com [209.85.215.180]) by imf21.hostedemail.com (Postfix) with ESMTP id 47ACB1C002A for ; Tue, 24 May 2022 06:27:46 +0000 (UTC) Received: by mail-pg1-f180.google.com with SMTP id h186so15532238pgc.3 for ; Mon, 23 May 2022 23:27:57 -0700 (PDT) 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=2mx9bPTY7AEcp+j24lhXXPGVls/yhivZ1agLRVxoLiw=; b=v+S3AKD3IZY1715alsr8yTzbsVUYEJKe+49LFvD+HdqE9G/w+5EjzEN0EwaEDyGrgn i9Ya3PVga4iPV58AJIeN1oTrMCpdjatANgHWEgSW8H8UHrlDSX4k0sGGqWcV7AXdFW13 EAk3nLfKEjQm6om5mFrDB7o4f02o242GQEXT/WIFEL4yR/3PpF7M5gtnBfzi+dSVbTxu StmM8BZkmo2YtgyD2u3N/KxcgJyaZoQ5QI6XjNdjDbH/gX13NzTb6mqHMmzWnw0wjnjt 6G2U6k80RGyCUtx5VNIlrbZZrmZIkm6UOOp3C70ojMsYgXdvqPAfokDNwMjQRVy8THGC Q/Ew== 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=2mx9bPTY7AEcp+j24lhXXPGVls/yhivZ1agLRVxoLiw=; b=gO1wpUtFWU1GruCFSutGVvLqAdGseqgkDVLYh9G5a3LfUC3Pk7edZo1C77Hn/sBj9l z8V8925n1yw9EbVdhOc8db6vTZLZYxKIxaLfC1CPFZA9F3iRLoD+DK8fA6WxiNyXKu1o /VtqF/vfuzOsdjskLAbxJG0NUQD+fKkaRzOefudj39lcQpA4/rVpyj/HjcnPLAgwnf73 0FSULUtznMtomsjwIbakGX/eLKh+V/FQjPU96Pa5EytyIcUFZeIvjJpvXPqzCZX5RQgG MN7N2Qub8PVbZ+HVVcLrt6WZNqzfqyzCukAgea65MOZa7RtC5fFQBFxqmaKtH/j+D/Id m6CQ== X-Gm-Message-State: AOAM533LSmoijQU6CWe9JeaCLOezhAjazKyFOSVt3KPfKOTeYciWWYCD Q+5Ap5DBFZvfI4KB8EVw8j8wDw== X-Google-Smtp-Source: ABdhPJx7zUzEoXA0gBdm9ca0a2T/LuHVii8K0J7cqNEy85oapg7WfQ/2eJWO3OwS2W/T0/ARUmA1jA== X-Received: by 2002:a62:f901:0:b0:518:307a:b392 with SMTP id o1-20020a62f901000000b00518307ab392mr27007106pfh.44.1653373677075; Mon, 23 May 2022 23:27:57 -0700 (PDT) Received: from FVFYT0MHHV2J.bytedance.net ([2408:8207:18da:2310:f940:af17:c2f5:8656]) by smtp.gmail.com with ESMTPSA id h5-20020a170902f54500b0016168e90f2dsm6254455plf.219.2022.05.23.23.27.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 May 2022 23:27:56 -0700 (PDT) From: Muchun Song To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com, longman@redhat.com, Muchun Song Subject: [PATCH v4 06/11] mm: thp: make split queue lock safe when LRU pages are reparented Date: Tue, 24 May 2022 14:05:46 +0800 Message-Id: <20220524060551.80037-7-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.1 (Apple Git-133) In-Reply-To: <20220524060551.80037-1-songmuchun@bytedance.com> References: <20220524060551.80037-1-songmuchun@bytedance.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 47ACB1C002A X-Stat-Signature: 9f8on8b9bmh16bjsmxuo4nkpqq5fw56d Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=v+S3AKD3; dmarc=pass (policy=none) header.from=bytedance.com; spf=pass (imf21.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.215.180 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1653373666-723252 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: Similar to the lruvec lock, we use the same approach to make the split queue lock safe when LRU pages are reparented. Signed-off-by: Muchun Song Acked-by: Roman Gushchin . --- mm/huge_memory.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ea152bde441e..cc596034c487 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -543,9 +543,22 @@ static struct deferred_split *folio_split_queue_lock(struct folio *folio) { struct deferred_split *queue; + rcu_read_lock(); +retry: queue = folio_split_queue(folio); spin_lock(&queue->split_queue_lock); + if (unlikely(folio_split_queue_memcg(folio, queue) != folio_memcg(folio))) { + spin_unlock(&queue->split_queue_lock); + goto retry; + } + + /* + * Preemption is disabled in the internal of spin_lock, which can serve + * as RCU read-side critical sections. + */ + rcu_read_unlock(); + return queue; } @@ -554,9 +567,19 @@ folio_split_queue_lock_irqsave(struct folio *folio, unsigned long *flags) { struct deferred_split *queue; + rcu_read_lock(); +retry: queue = folio_split_queue(folio); spin_lock_irqsave(&queue->split_queue_lock, *flags); + if (unlikely(folio_split_queue_memcg(folio, queue) != folio_memcg(folio))) { + spin_unlock_irqrestore(&queue->split_queue_lock, *flags); + goto retry; + } + + /* See the comments in folio_split_queue_lock(). */ + rcu_read_unlock(); + return queue; }