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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 6BF57C2BBC7 for ; Mon, 13 Apr 2020 12:52:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 483DF2075E for ; Mon, 13 Apr 2020 12:52:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729587AbgDMMw1 (ORCPT ); Mon, 13 Apr 2020 08:52:27 -0400 Received: from mga12.intel.com ([192.55.52.136]:52670 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728678AbgDMMw0 (ORCPT ); Mon, 13 Apr 2020 08:52:26 -0400 IronPort-SDR: Jw5lZlABpWM74rSQrb/DSdR5A4+YDTg/lh7dVZaj+LaAsx9MKkiRqxxSMzcOzWohmBBM3tUl23 Jw/C1ARtO8MQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2020 05:52:24 -0700 IronPort-SDR: uX4ABe3J8BFw6CE0XOBP3vQpTRfwCI32Qtsy2kGMt35MgULzu1PHKCGCxZoIBH1G+5mttR3MGv gWMt1s4i+C7Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,378,1580803200"; d="scan'208";a="245132797" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga008.fm.intel.com with ESMTP; 13 Apr 2020 05:52:22 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id DE69A1A5; Mon, 13 Apr 2020 15:52:21 +0300 (EEST) From: "Kirill A. Shutemov" To: akpm@linux-foundation.org, Andrea Arcangeli Cc: Zi Yan , Yang Shi , Ralph Campbell , John Hubbard , William Kucharski , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv3, RESEND 3/8] khugepaged: Drain all LRU caches before scanning pages Date: Mon, 13 Apr 2020 15:52:15 +0300 Message-Id: <20200413125220.663-4-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200413125220.663-1-kirill.shutemov@linux.intel.com> References: <20200413125220.663-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Having a page in LRU add cache offsets page refcount and gives false-negative on PageLRU(). It reduces collapse success rate. Drain all LRU add caches before scanning. It happens relatively rare and should not disturb the system too much. Signed-off-by: Kirill A. Shutemov --- mm/khugepaged.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 5968ec5ddd6b..ee66c140c2d6 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2059,6 +2059,8 @@ static void khugepaged_do_scan(void) barrier(); /* write khugepaged_pages_to_scan to local stack */ + lru_add_drain_all(); + while (progress < pages) { if (!khugepaged_prealloc_page(&hpage, &wait)) break; -- 2.26.0