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,URIBL_BLOCKED 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 D1406C433DF for ; Wed, 3 Jun 2020 23:00:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8F07A208E4 for ; Wed, 3 Jun 2020 23:00:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vb7S+f/a" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F07A208E4 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 30D7F280044; Wed, 3 Jun 2020 19:00:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2E47E280003; Wed, 3 Jun 2020 19:00:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 22200280044; Wed, 3 Jun 2020 19:00:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0037.hostedemail.com [216.40.44.37]) by kanga.kvack.org (Postfix) with ESMTP id 094E8280003 for ; Wed, 3 Jun 2020 19:00:16 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D156833CD for ; Wed, 3 Jun 2020 23:00:15 +0000 (UTC) X-FDA: 76889420790.14.smash89_1f5a51d5f761a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id AF9F918229837 for ; Wed, 3 Jun 2020 23:00:15 +0000 (UTC) X-HE-Tag: smash89_1f5a51d5f761a X-Filterd-Recvd-Size: 2890 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Wed, 3 Jun 2020 23:00:15 +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 5904820B80; Wed, 3 Jun 2020 23:00:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591225214; bh=EBzgc3GwurC/6VRTO8zibqJZM9uYGtHqpdRFnsg7pwo=; h=Date:From:To:Subject:In-Reply-To:From; b=Vb7S+f/aBRlcKnDYgKeZGMJvPSiBIebvEEqJeKVwSS1fvlvqxf7wBWpHQFfJMkryX 8rgqMhc9fiM+zgze7N0yAb5owQM3wl19mUvmTHsNKa/FKir0Sxsxv27Gb0q86rewDn CWjm6lUUFN+m5hSaUJ2vdVxbnEbaFGL4tNx6hnNc= Date: Wed, 03 Jun 2020 16:00:12 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, jhubbard@nvidia.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, rcampbell@nvidia.com, torvalds@linux-foundation.org, william.kucharski@oracle.com, yang.shi@linux.alibaba.com, ziy@nvidia.com Subject: [patch 063/131] khugepaged: drain all LRU caches before scanning pages Message-ID: <20200603230012.MhU1P4AY1%akpm@linux-foundation.org> In-Reply-To: <20200603155549.e041363450869eaae4c7f05b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: AF9F918229837 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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: "Kirill A. Shutemov" Subject: khugepaged: drain all LRU caches before scanning pages 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. Link: http://lkml.kernel.org/r/20200416160026.16538-4-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reviewed-by: William Kucharski Reviewed-by: Zi Yan Tested-by: Zi Yan Acked-by: Yang Shi Cc: Andrea Arcangeli Cc: John Hubbard Cc: Mike Kravetz Cc: Ralph Campbell Signed-off-by: Andrew Morton --- mm/khugepaged.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/khugepaged.c~khugepaged-drain-all-lru-caches-before-scanning-pages +++ a/mm/khugepaged.c @@ -2079,6 +2079,8 @@ 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; _