From patchwork Sun Dec 1 01:57:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11268449 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A905317F0 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 765702082E for ; Sun, 1 Dec 2019 01:57:22 +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 765702082E 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) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 5F3786B0373; Sat, 30 Nov 2019 20:57:21 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org 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-Original-To: linux-mm@kvack.org 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-Spam-Summary: 2,0,0,017ec6ca98c0ede4,d41d8cd98f00b204,akpm@linux-foundation.org,:akpm@linux-foundation.org:hannes@cmpxchg.org:hughd@google.com:kirill.shutemov@linux.intel.com::mm-commits@vger.kernel.org:songliubraving@fb.com:torvalds@linux-foundation.org:william.kucharski@oracle.com:willy@infradead.org,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3867:3868:3870:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7576:8599:8660:8957:9025:9545:10004:10913:11026:11658:11914:12043:12048:12296:12297:12517:12519:12555:12679:12783:12986:13069:13148:13184:13229:13230:13255:13311:13357:14096:14181:14384:14721:14849:21080:21433:21451:21611:21627:21740:21939:30054:30064,0,RBL:error,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL: neutral, 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);