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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 14EE8C63777 for ; Sun, 22 Nov 2020 06:17:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B490C2137B for ; Sun, 22 Nov 2020 06:17:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="kuXrdfOU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B490C2137B 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 5580D6B007B; Sun, 22 Nov 2020 01:17:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E0786B007D; Sun, 22 Nov 2020 01:17:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3A7466B007E; Sun, 22 Nov 2020 01:17:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0249.hostedemail.com [216.40.44.249]) by kanga.kvack.org (Postfix) with ESMTP id 0CA9B6B007B for ; Sun, 22 Nov 2020 01:17:25 -0500 (EST) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id AD75E281F for ; Sun, 22 Nov 2020 06:17:24 +0000 (UTC) X-FDA: 77511047208.01.act05_340d15e2735a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 8BD47100507A9 for ; Sun, 22 Nov 2020 06:17:24 +0000 (UTC) X-HE-Tag: act05_340d15e2735a X-Filterd-Recvd-Size: 2781 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Sun, 22 Nov 2020 06:17:23 +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 A8DFB21D81; Sun, 22 Nov 2020 06:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1606025843; bh=nNBCUnSKcDrkF+Ddihz6zZ5lsSOminmqsaiRjEho7Es=; h=Date:From:To:Subject:In-Reply-To:From; b=kuXrdfOU8OXzCvTn62acRPePkNnw84tGQeloRY+6uoWiBBDCIWjIUNp/YOyyDwU3g +WVNMZWQ/NFxMO0qxwbPaym/KkVsp11PlrZa2AKYtM+ElS3MyMzgG6rTgqoXSrn+bp 44knvaupA1uKWmFlrwuQtI2sGztUvcpgFPMKNKvE= Date: Sat, 21 Nov 2020 22:17:22 -0800 From: Andrew Morton To: akpm@linux-foundation.org, feng.tang@intel.com, hannes@cmpxchg.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, rong.a.chen@intel.com, torvalds@linux-foundation.org, william.kucharski@oracle.com, willy@infradead.org, zhengjun.xing@linux.intel.com Subject: [patch 8/8] mm: fix madvise WILLNEED performance problem Message-ID: <20201122061722.Tef3ViFuW%akpm@linux-foundation.org> In-Reply-To: <20201121221631.948ae4655e913a319d61700a@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: "Matthew Wilcox (Oracle)" Subject: mm: fix madvise WILLNEED performance problem The calculation of the end page index was incorrect, leading to a regression of 70% when running stress-ng. With this fix, we instead see a performance improvement of 3%. Link: https://lkml.kernel.org/r/20201109134851.29692-1-willy@infradead.org Fixes: e6e88712e43b ("mm: optimise madvise WILLNEED") Signed-off-by: Matthew Wilcox (Oracle) Reported-by: kernel test robot Tested-by: Xing Zhengjun Acked-by: Johannes Weiner Cc: William Kucharski Cc: Feng Tang Cc: "Chen, Rong A" Signed-off-by: Andrew Morton --- mm/madvise.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/madvise.c~mm-fix-madvise-willneed-performance-problem +++ a/mm/madvise.c @@ -226,7 +226,7 @@ static void force_shm_swapin_readahead(s struct address_space *mapping) { XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); - pgoff_t end_index = end / PAGE_SIZE; + pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1); struct page *page; rcu_read_lock(); _