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=-20.4 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 1EF42C433E1 for ; Tue, 18 Aug 2020 18:47:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F222320772 for ; Tue, 18 Aug 2020 18:47:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CIx7kMWb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726739AbgHRSrV (ORCPT ); Tue, 18 Aug 2020 14:47:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726699AbgHRSrP (ORCPT ); Tue, 18 Aug 2020 14:47:15 -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 8479FC061342 for ; Tue, 18 Aug 2020 11:47:15 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id u189so23077270ybg.17 for ; Tue, 18 Aug 2020 11:47:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=bfVQLroskM5Wc4DhZMIyj9jgHc+j8RHZ/garHr4Fpmo=; b=CIx7kMWbB8VmYnYBEoD4nNQsaSQZt1zzWgyHBo9TmOh+81P13Aq4a+yETjPZEdKzHt 6xhM+il6SYmrYbNG1IV7d069OMSWVqj57ViYi+dViNBbqPDo4foz1/sXg+neeEwOnROJ b3vK60iuFFWLcpf66/+S0SZnj2eh8Khpc1C4Awp23aYoNw3Hn2ktDyYyIqmyY/lLuNWy 0KsGsEIVRDT/ZcJr7rljERS6QGsxhldWu58VpPBprIVTjCTNGFYgQ/jP9PX7jqtcNwYD yHdVBEoP2GYwds522u6f/lZ7QVEz357iUqWtZYvud/ZMRq5iE6U6JD54o1RFc5iL68P9 PFUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=bfVQLroskM5Wc4DhZMIyj9jgHc+j8RHZ/garHr4Fpmo=; b=iY01raQyfOyZWtXtW7mLPCUfGvIk30Q8ZHmkVY7v8Hdhg5rEKetly4h5A8N43B39cY 2h6yOf55FlrB2/VB6DLJcsnH/+awFeZRau0P6HYvEMOFj8zYIvtwJ6Nb9ygj/iLGavvM Nzv1cUp7SNBXxSsmlwBEgrRBGH9EvCR4wZBBq30uAeQXjo631MwMwfH44jelm/H/sJCs grIt7BWwrKYlSNdX1dPd6G5jPbU6buVDTPJR/W04EBqIJfOFwvckCm81crBWHjYCaaZH 1eptPL9LUNzMHuWW0TKaqkfO5JZXkYr5M1mmCUH44vQDXe0OdCRnqIR/b0jExMW1i9mn f2uw== X-Gm-Message-State: AOAM533UvWAmdLVzZPcw3IF2MezJO0sUQI3ThjIDfkKqCHXCwktMUO0d DpXo68L6uykMogK0prr9Q9Tf10fx9pM= X-Google-Smtp-Source: ABdhPJxZwwFPlarZ3LoosIXt55p8uBBCrvGv9J5VLrCxYXf9wPeT384wi+a1vkBEDJm/7ct0Z09BbNo6pl0= X-Received: by 2002:a25:a091:: with SMTP id y17mr28606051ybh.82.1597776434643; Tue, 18 Aug 2020 11:47:14 -0700 (PDT) Date: Tue, 18 Aug 2020 12:47:04 -0600 In-Reply-To: <20200818184704.3625199-1-yuzhao@google.com> Message-Id: <20200818184704.3625199-3-yuzhao@google.com> Mime-Version: 1.0 References: <20200818184704.3625199-1-yuzhao@google.com> X-Mailer: git-send-email 2.28.0.220.ged08abb693-goog Subject: [PATCH v2 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, Joonsoo Kim , 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 1aaea26556cc..75240c7ef73f 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 999a84dbe12c..40bf20a75278 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) @@ -900,8 +899,6 @@ 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) -- 2.28.0.220.ged08abb693-goog