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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 D037FC43613 for ; Mon, 24 Jun 2019 14:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B37F3212F5 for ; Mon, 24 Jun 2019 14:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731936AbfFXOJz (ORCPT ); Mon, 24 Jun 2019 10:09:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:40706 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731916AbfFXOJx (ORCPT ); Mon, 24 Jun 2019 10:09:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 86070AF2C; Mon, 24 Jun 2019 14:09:52 +0000 (UTC) Date: Mon, 24 Jun 2019 15:09:50 +0100 From: Mel Gorman To: Huang Ying Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rik van Riel , Peter Zijlstra , jhladky@redhat.com, lvenanci@redhat.com, Ingo Molnar Subject: Re: [PATCH -mm] autonuma: Fix scan period updating Message-ID: <20190624140950.GF2947@suse.de> References: <20190624025604.30896-1-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20190624025604.30896-1-ying.huang@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 24, 2019 at 10:56:04AM +0800, Huang Ying wrote: > The autonuma scan period should be increased (scanning is slowed down) > if the majority of the page accesses are shared with other processes. > But in current code, the scan period will be decreased (scanning is > speeded up) in that situation. > > This patch fixes the code. And this has been tested via tracing the > scan period changing and /proc/vmstat numa_pte_updates counter when > running a multi-threaded memory accessing program (most memory > areas are accessed by multiple threads). > The patch somewhat flips the logic on whether shared or private is considered and it's not immediately obvious why that was required. That aside, other than the impact on numa_pte_updates, what actual performance difference was measured and on on what workloads? -- Mel Gorman SUSE Labs