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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 7E67DC352BE for ; Thu, 16 Apr 2020 16:00:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D5CC214AF for ; Thu, 16 Apr 2020 16:00:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D5CC214AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9ED7B8E00C7; Thu, 16 Apr 2020 12:00:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C5708E00BC; Thu, 16 Apr 2020 12:00:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B3588E00C7; Thu, 16 Apr 2020 12:00:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id 752268E00BC for ; Thu, 16 Apr 2020 12:00:39 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3801C181AC9CB for ; Thu, 16 Apr 2020 16:00:39 +0000 (UTC) X-FDA: 76714180998.01.debt65_7a0925402e20b X-HE-Tag: debt65_7a0925402e20b X-Filterd-Recvd-Size: 2768 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Apr 2020 16:00:38 +0000 (UTC) IronPort-SDR: qF3AzpCy1pKKaV5uvPXKmYSQJMvlkBgI0iBp4EuwOi4n/IpPHlai6as36K+veA8jm+XI+CZn7L YnQ5ioNW/7rg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2020 09:00:36 -0700 IronPort-SDR: NQIcM0V3MN2Fg/uMznKWIBC3Pdni5h6eJawVvQTVFnCw969sy6vJ89vFVR2vHDLDK2HEGxPdqE rqdqI2AvGKfg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,391,1580803200"; d="scan'208";a="454377398" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga005.fm.intel.com with ESMTP; 16 Apr 2020 09:00:33 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 6B6F249F; Thu, 16 Apr 2020 19:00:31 +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: [PATCHv4 3/8] khugepaged: Drain all LRU caches before scanning pages Date: Thu, 16 Apr 2020 19:00:21 +0300 Message-Id: <20200416160026.16538-4-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200416160026.16538-1-kirill.shutemov@linux.intel.com> References: <20200416160026.16538-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: 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 Reviewed-by: William Kucharski Reviewed-and-Tested-by: Zi Yan Acked-by: Yang Shi --- mm/khugepaged.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 6e69dc9a9fb1..0b75b9821f44 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2078,6 +2078,8 @@ static void khugepaged_do_scan(void) =20 barrier(); /* write khugepaged_pages_to_scan to local stack */ =20 + lru_add_drain_all(); + while (progress < pages) { if (!khugepaged_prealloc_page(&hpage, &wait)) break; --=20 2.26.1