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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 07D1EC432C0 for ; Sun, 1 Dec 2019 01:57:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B7FAF2082E for ; Sun, 1 Dec 2019 01:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="X48K46Hz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7FAF2082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 61CD06B0370; Sat, 30 Nov 2019 20:57:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F3786B0373; Sat, 30 Nov 2019 20:57:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 530C26B0375; Sat, 30 Nov 2019 20:57:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0137.hostedemail.com [216.40.44.137]) by kanga.kvack.org (Postfix) with ESMTP id 3998C6B0370 for ; Sat, 30 Nov 2019 20:57:21 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id E6AB5181AEF0B for ; Sun, 1 Dec 2019 01:57:20 +0000 (UTC) X-FDA: 76214910240.17.edge78_401df609de730 X-HE-Tag: edge78_401df609de730 X-Filterd-Recvd-Size: 3175 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Dec 2019 01:57:20 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 89387205ED; Sun, 1 Dec 2019 01:57:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575165439; bh=BDLE4/Rlprx1ErkpuDLXCnGyWIoYaXR+PrjZR0eY0n4=; h=Date:From:To:Subject:From; b=X48K46HzBfjDWbDa+8CqNFKGPSrqioRwPkHpUjOjA83fQRyAYzWzZ+4N57JIqEEnp gpy2+bRkoMt8TPwgRQznmvRJagi+2e4IeVL7nY3Gf0clygVsrOmcigI7EYLykZx7mj wRESj7boKrZK7wwrWICgOc7Q+Bryx5eYll0iHMxM= Date: Sat, 30 Nov 2019 17:57:19 -0800 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, hannes@cmpxchg.org, hughd@google.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, songliubraving@fb.com, torvalds@linux-foundation.org, william.kucharski@oracle.com, willy@infradead.org Subject: [patch 136/158] mm/thp: flush file for !is_shmem PageDirty() case in collapse_file() Message-ID: <20191201015719.31Qrkfi64%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Song Liu Subject: mm/thp: flush file for !is_shmem PageDirty() case in collapse_file() For non-shmem file THPs, khugepaged only collapses read only .text mapping (VM_DENYWRITE). These pages should not be dirty except the case where the file hasn't been flushed since first write. Call filemap_flush() in collapse_file() to accelerate the write back in such cases. Link: http://lkml.kernel.org/r/20191106060930.2571389-3-songliubraving@fb.com Signed-off-by: Song Liu Cc: Kirill A. Shutemov Cc: Hugh Dickins Cc: William Kucharski Cc: Johannes Weiner Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- mm/khugepaged.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/mm/khugepaged.c~mm-thp-flush-file-for-is_shmem-pagedirty-case-in-collapse_file +++ a/mm/khugepaged.c @@ -1602,6 +1602,24 @@ static void collapse_file(struct mm_stru result = SCAN_FAIL; goto xa_unlocked; } + } else if (PageDirty(page)) { + /* + * khugepaged only works on read-only fd, + * so this page is dirty because it hasn't + * been flushed since first write. There + * won't be new dirty pages. + * + * Trigger async flush here and hope the + * writeback is done when khugepaged + * revisits this page. + * + * This is a one-off situation. We are not + * forcing writeback in loop. + */ + xas_unlock_irq(&xas); + filemap_flush(mapping); + result = SCAN_FAIL; + goto xa_unlocked; } else if (trylock_page(page)) { get_page(page); xas_unlock_irq(&xas); _