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=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 EDAE2C433E1 for ; Wed, 12 Aug 2020 04:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF69420678 for ; Wed, 12 Aug 2020 04:06:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ux5Uu8bQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726606AbgHLEGf (ORCPT ); Wed, 12 Aug 2020 00:06:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725825AbgHLEGe (ORCPT ); Wed, 12 Aug 2020 00:06:34 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14B1AC06174A for ; Tue, 11 Aug 2020 21:06:34 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id g127so1424510ybf.11 for ; Tue, 11 Aug 2020 21:06:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:message-id:mime-version:subject:from:to:cc; bh=FIDHeBVsxOsjTSA4w3NTw9Tbo6FlzORttBwxcXHesPo=; b=ux5Uu8bQKrzTp3HdJ4kJsnBlROLefp/k9fpAqAOEUdQCbrkbaMwDrum/ZlZvBSAvI0 3g1wg6FghbYkoDYlmie3Tr8cLXl1nBR20e2mXExEEErvtoLGTMTuApukeAjegxF/R9o5 Z01vMuGk80s052RBzwQFTGqcOU3yogmOINf/19ezFHhUypIDKY+kDHzsd+gh0CGMV+Qk s5OgPUsfbMCq1LG1HE/j+UxYS1/F6pbtcTkgoT+mBFvUn85xmd27KWsMdSiMZh0cBVjX I/cpckvsX2JUf+KAT/xtyVk8afH10m2yi3pgn0Lzz7kFDQEAflnCV5f0cN4XjIScOU2r Y8CQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:message-id:mime-version:subject :from:to:cc; bh=FIDHeBVsxOsjTSA4w3NTw9Tbo6FlzORttBwxcXHesPo=; b=shZok/yRUsAGNT49bQYNHQFVBccUknN0NoRSsj3nY1SF4UluoKL6CkJ/2nCPpVxY63 rNMk0tg+0eVBPpKDmrZwLHDVoFtRYTzJ0Il9ngSb/xRCBBU0raRnWxoC6Ax2adcs0gQr IZZOMuGID9wR5QUv0lyDUwNtT05BUzJJVAmeTe10ZMNOGkWtp8fxKsSFSYWArbZSqtV8 PVIyf6Ri8qVWN8ZiHJMBm4yRmI/1Ol2Zseg5/1fgZUybEGJlWdCqd9L7N5yoa3Gnkghr wja/FJcJdr2aPEdMceXbvL0a5R+LCf+lhHTjnXfkyxH+kNdIrNpPnU+yy4hhyBJz1TDY 2uSA== X-Gm-Message-State: AOAM530gyUYwt0BxmPu0RmDnwA0p19R1tm0JimC0aDV5L0wPlOZTmwbo ec992MKDeMEGonpD0dwmuvmsG2aBINo= X-Google-Smtp-Source: ABdhPJzUzwFvnMR3FToe6QoDQuvIwCq7pGDkgNw1NnVna6H//Q1976w39eSM3NOkYmiN1L3BjTLJrLyy8rI= X-Received: by 2002:a5b:70d:: with SMTP id g13mr52265619ybq.160.1597205193285; Tue, 11 Aug 2020 21:06:33 -0700 (PDT) Reply-To: <20200812040454.2708263-1-yuzhao@google.com> Date: Tue, 11 Aug 2020 22:06:30 -0600 Message-Id: <20200812040630.2710064-1-yuzhao@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog Subject: [PATCH 3/3] mm: remove superfluous __ClearPageWaiters() From: Yu Zhao To: Andrew Morton Cc: Alexander Duyck , Huang Ying , David Hildenbrand , Michal Hocko , Yang Shi , Qian Cai , Mel Gorman , Nicholas Piggin , "=?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?=" , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yu Zhao Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Presumably __ClearPageWaiters() was added to follow the previously removed __ClearPageActive() pattern. Only flags that are in PAGE_FLAGS_CHECK_AT_FREE needs to be properly cleared because otherwise we think there may be some kind of leak. PG_waiters is not one of those flags and leaving the clearing to PAGE_FLAGS_CHECK_AT_PREP is more appropriate. Signed-off-by: Yu Zhao --- include/linux/page-flags.h | 2 +- mm/filemap.c | 2 ++ mm/memremap.c | 2 -- mm/swap.c | 3 --- 4 files changed, 3 insertions(+), 6 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 6be1aa559b1e..dba80a2bdfba 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -318,7 +318,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; } TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) __PAGEFLAG(Locked, locked, PF_NO_TAIL) -PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) +PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) PAGEFLAG(Referenced, referenced, PF_HEAD) TESTCLEARFLAG(Referenced, referenced, PF_HEAD) diff --git a/mm/filemap.c b/mm/filemap.c index f2bb5ff0293d..8a096844ddad 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1079,6 +1079,8 @@ static void wake_up_page_bit(struct page *page, int bit_nr) * other pages on it. * * That's okay, it's a rare case. The next waker will clear it. + * Otherwise the bit will be cleared by PAGE_FLAGS_CHECK_AT_PREP + * when the page is being freed. */ } spin_unlock_irqrestore(&q->lock, flags); diff --git a/mm/memremap.c b/mm/memremap.c index 3a06eb91cb59..a9d02ffaf9e3 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -451,8 +451,6 @@ void free_devmap_managed_page(struct page *page) return; } - __ClearPageWaiters(page); - mem_cgroup_uncharge(page); /* diff --git a/mm/swap.c b/mm/swap.c index 1f223a02549d..6129692752a5 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -90,7 +90,6 @@ static void __page_cache_release(struct page *page) del_page_from_lru_list(page, lruvec, page_off_lru(page)); spin_unlock_irqrestore(&pgdat->lru_lock, flags); } - __ClearPageWaiters(page); } static void __put_single_page(struct page *page) @@ -898,8 +897,6 @@ void release_pages(struct page **pages, int nr) del_page_from_lru_list(page, lruvec, page_off_lru(page)); } - __ClearPageWaiters(page); - list_add(&page->lru, &pages_to_free); } if (locked_pgdat) -- 2.28.0.236.gb10cc79966-goog