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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 BAB95C282DD for ; Wed, 8 Jan 2020 16:07:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C5CE2072A for ; Wed, 8 Jan 2020 16:07:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729086AbgAHQH4 (ORCPT ); Wed, 8 Jan 2020 11:07:56 -0500 Received: from mga11.intel.com ([192.55.52.93]:65235 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727338AbgAHQH4 (ORCPT ); Wed, 8 Jan 2020 11:07:56 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 08:07:55 -0800 X-IronPort-AV: E=Sophos;i="5.69,410,1571727600"; d="scan'208";a="211581775" Received: from ahduyck-desk1.jf.intel.com ([10.7.198.76]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 08:07:52 -0800 Message-ID: <783a534b37500c36a0255b5a7615b667a89b5b76.camel@linux.intel.com> Subject: Re: [PATCH v16 7/9] mm: Rotate free list so reported pages are moved to the tail of the list From: Alexander Duyck To: David Hildenbrand , Alexander Duyck , kvm@vger.kernel.org, mst@redhat.com, linux-kernel@vger.kernel.org, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, mgorman@techsingularity.net, vbabka@suse.cz Cc: yang.zhang.wz@gmail.com, nitesh@redhat.com, konrad.wilk@oracle.com, pagupta@redhat.com, riel@surriel.com, lcapitulino@redhat.com, dave.hansen@intel.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, osalvador@suse.de Date: Wed, 08 Jan 2020 08:07:52 -0800 In-Reply-To: <1ee73115-b5b7-9de8-08b0-528035111ea8@redhat.com> References: <20200103210509.29237.18426.stgit@localhost.localdomain> <20200103211657.29237.50194.stgit@localhost.localdomain> <1ee73115-b5b7-9de8-08b0-528035111ea8@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.5 (3.32.5-1.fc30) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 2020-01-08 at 14:38 +0100, David Hildenbrand wrote: > On 03.01.20 22:16, Alexander Duyck wrote: > > From: Alexander Duyck > > > > Rather than walking over the same pages again and again to get to the pages > > that have yet to be reported we can save ourselves a significant amount of > > time by simply rotating the list so that when we have a full list of > > reported pages the head of the list is pointing to the next non-reported > > page. Doing this should save us some significant time when processing each > > free list. > > > > This doesn't gain us much in the standard case as all of the non-reported > > pages should be near the top of the list already. However in the case of > > page shuffling this results in a noticeable improvement. Below are the > > will-it-scale page_fault1 w/ THP numbers for 16 tasks with and without > > this patch. > > > > Without: > > tasks processes processes_idle threads threads_idle > > 16 8093776.25 0.17 5393242.00 38.20 > > > > With: > > tasks processes processes_idle threads threads_idle > > 16 8283274.75 0.17 5594261.00 38.15 > > > > Signed-off-by: Alexander Duyck > > --- > > mm/page_reporting.c | 30 ++++++++++++++++++++++-------- > > 1 file changed, 22 insertions(+), 8 deletions(-) > > Just a minor comment while scanning over the patches (will do more > review soon), you might want to switch to "mm/page_reporting: " styled > subjects for these optimizations. > Okay, I will update if needed for the next version.