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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62862C432BE for ; Sat, 14 Aug 2021 05:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 435C260E78 for ; Sat, 14 Aug 2021 05:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237185AbhHNF0k (ORCPT ); Sat, 14 Aug 2021 01:26:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237257AbhHNF0g (ORCPT ); Sat, 14 Aug 2021 01:26:36 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48B60C061757 for ; Fri, 13 Aug 2021 22:26:08 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id qe12-20020a17090b4f8c00b00179321cbae7so8463924pjb.2 for ; Fri, 13 Aug 2021 22:26:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QGMUDL+X4tm/vJIxNFScO4bfVyq5TxNYHUST0OzJycs=; b=Awt006hzmvp3826E028AW54ZQdcH/iHJCFQh7D9WUYxFSVFbozsLRpX7pQ6JEIbg9W s4SyjyqL9SpQNj5AOBfRol+2Kcok6r9Fmk4sH07/7Rxg6R8djmoy6Rc0pKWV+wPdbKBq QkaIJ9bx9o5fdhBlierm42heq3f4pVeSrmi2XaepkVDKf6KsaxR/iom6ChVarEzFNycO TgxgCEjhQw+v9g3ClTw9De3JOtcS0gkL1Oxwz2orY/wTPDBR3qCjPMc8ZJRo9PYZ+rYA dNi8x/tbixxIlvFIaMh6OyuxbSDVbh/X3m8LKHGD15HXOdaD9NlcclnMEcybsIXFNapR CAGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QGMUDL+X4tm/vJIxNFScO4bfVyq5TxNYHUST0OzJycs=; b=ABPDSrd2aA9Fqf2UyYV0MnI2hzdd77wF8y+hoLvsUYfIUz+lprtfB3peyzuUnKK9V3 ENqf3hU8j0wTLaNDF29uo43KFDZNJ/WYwJrrw9Mj65rydSM1D62w6+aynlo43HqB5xjE JlhslcL09AUV+lFqZ84eOuaieYjEKMfXHEWmugwLWQnuqmT0t+j9e4cya0ZBPrP7FQYQ hAMj1wyJzBSi8lzkC+JNJAEnqEMhUaQiuybCQMicGwBWEHsa81ySnP/DSRl/r54tNKlk sGztvSO0Hu1Syq7L1haEZmlJ8ypkhD9omslFiWBjDQDwD4+nrdYVYy9BhtIwkuCqs8hO ldGw== X-Gm-Message-State: AOAM530QQduOMse+WfIWl65NtN0BvYbIB9aZYhj8jsTZA+UkU5W5MkXW Zor+eUdFCnX/Bkh+B/LYelRUfg== X-Google-Smtp-Source: ABdhPJxAx+pnIIz1Pwn50bFJeyyCUDyRI7YRH37fF9YnbX2dv1IvGhcPf/LkKmZqfJrEz5hhj6s9pg== X-Received: by 2002:a63:5153:: with SMTP id r19mr5516505pgl.56.1628918767822; Fri, 13 Aug 2021 22:26:07 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.237]) by smtp.gmail.com with ESMTPSA id s5sm4783133pgp.81.2021.08.13.22.26.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Aug 2021 22:26:07 -0700 (PDT) From: Muchun Song To: guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, akpm@linux-foundation.org, shakeelb@google.com, vdavydov.dev@gmail.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, fam.zheng@bytedance.com, bsingharora@gmail.com, shy828301@gmail.com, alexs@kernel.org, smuchun@gmail.com, zhengqi.arch@bytedance.com, Muchun Song Subject: [PATCH v1 06/12] mm: thp: make split queue lock safe when LRU pages are reparented Date: Sat, 14 Aug 2021 13:25:13 +0800 Message-Id: <20210814052519.86679-7-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210814052519.86679-1-songmuchun@bytedance.com> References: <20210814052519.86679-1-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 c49ef28e48c1..22fbf2c74d49 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -535,9 +535,22 @@ 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(split_queue_memcg(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; } @@ -546,9 +559,19 @@ 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(split_queue_memcg(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