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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDC0AC433EF for ; Tue, 24 May 2022 06:28:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235011AbiEXG2I (ORCPT ); Tue, 24 May 2022 02:28:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234985AbiEXG17 (ORCPT ); Tue, 24 May 2022 02:27:59 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 813F172E1F for ; Mon, 23 May 2022 23:27:57 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id a9so13513213pgv.12 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=AFCkqLzTMjh69gAuhKv01elZcabg6YuuvBgKYM+X3BgrlExUoER5jgI2GZyat4EYx+ XBgQ7hIXkZZUhoZKMt56Pj0C77SEjpqQzVHZJaI6s1VKFrjY78UwjX7TtdTxi7jh+nNW LVK11KAB2F7d7KtclClldRbBP3sDFPUC8+9QnLNXuBqARnsja8olnv4uU8q05VMefwML rvjtsykQdQqLMGfcqPqbHO6yFZuodWZfj6ZEOb6TtUvuUpNuAXKjgmy4TWFptPwkaz8R u0FChzD5fc7kHaDySRzm0l5/1OdlmWYLPXGJhAc5ZMirdd2yWt99TxAQ4yYeuz9IWEtP 58/g== X-Gm-Message-State: AOAM530LzaPpFPyUTerh8MzsQyRRglUf/9v/FoCGCGEegf2DaFgJHA4j ND8mH/dazOsJSyZDIu3zKf6KJg== 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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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; } -- 2.11.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: 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> References: <20220524060551.80037-1-songmuchun@bytedance.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: 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== In-Reply-To: <20220524060551.80037-1-songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, duanxiongchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org, longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Muchun Song 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 --- 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; } -- 2.11.0