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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 81BEEC352BE for ; Fri, 17 Apr 2020 10:06:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EA08221EA for ; Fri, 17 Apr 2020 10:06:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mDpYd1gB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728799AbgDQKGo (ORCPT ); Fri, 17 Apr 2020 06:06:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725830AbgDQKGo (ORCPT ); Fri, 17 Apr 2020 06:06:44 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 590F5C061A0C for ; Fri, 17 Apr 2020 03:06:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=cOrb9bPUWtgd6Wsapeaho8G1pU3bJiwluL4FFzGvoDY=; b=mDpYd1gB+bi0K4T4b1v2Ciw4pB UIpwkgnCLwn7EJ8E43eLTiXToKyD7vCnn5f/+RDLTb4wEVE1AKWZq5y27rYTaouKNUL1doADfsHBS g4e49uwqq6dw+4sABzWQLf8R2J28Yvu3fUzjDSl4LOmfp/ca3DIMYuBG9MO87/vb46UgyltIgcBVe tqZe/VN94XQXkHZlFN0VhQmTAXOc/o3gZl80CZTsTawZ+vKl7Xe97Uvk/63Y39/t72JrDcykvywjV SSK5qmyEXIntmLYozQxcBrrceaBJ2zPOWWiOs0I/U6YOuLuuvq1nQt951OIlVEsHRlXz/yBwA0OZc WD2KJbWQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jPNtL-0000Hp-Tm; Fri, 17 Apr 2020 10:06:36 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 03B773006E0; Fri, 17 Apr 2020 12:06:33 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B68282B1213AC; Fri, 17 Apr 2020 12:06:33 +0200 (CEST) Date: Fri, 17 Apr 2020 12:06:33 +0200 From: Peter Zijlstra To: "Huang, Ying" Cc: Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ingo Molnar , Mel Gorman , Rik van Riel , Daniel Jordan , Tejun Heo , Dave Hansen , Tim Chen , Aubrey Li Subject: Re: [RFC] autonuma: Support to scan page table asynchronously Message-ID: <20200417100633.GU20730@hirez.programming.kicks-ass.net> References: <20200414081951.297676-1-ying.huang@intel.com> <20200414120646.GN3818@techsingularity.net> <20200415113226.GE20730@hirez.programming.kicks-ass.net> <87o8rsxlws.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87o8rsxlws.fsf@yhuang-dev.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 16, 2020 at 09:24:35AM +0800, Huang, Ying wrote: > Peter Zijlstra writes: > > > On Tue, Apr 14, 2020 at 01:06:46PM +0100, Mel Gorman wrote: > >> While it's just an opinion, my preference would be to focus on reducing > >> the cost and amount of scanning done -- particularly for threads. > > > > This; I really don't believe in those back-charging things, esp. since > > not having cgroups or having multiple applications in a single cgroup is > > a valid setup. > > Technically, it appears possible to back-charge the CPU time to the > process/thread directly (not the cgroup). I've yet to see a sane proposal there. What we're not going to do is make regular task accounting more expensive than it already is.