Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753651Ab2KPV3Q (ORCPT ); Fri, 16 Nov 2012 16:29:16 -0500 Received: from mga09.intel.com ([134.134.136.24]:4069 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753520Ab2KPV3P (ORCPT ); Fri, 16 Nov 2012 16:29:15 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.83,266,1352102400"; d="scan'208";a="220828243" Message-ID: <50A6B01F.3000708@linux.intel.com> Date: Fri, 16 Nov 2012 13:29:03 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2 MIME-Version: 1.0 To: David Rientjes CC: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli , linux-mm@kvack.org, Andi Kleen , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [PATCH v5 11/11] thp, vmstat: implement HZP_ALLOC and HZP_ALLOC_FAILED events References: <1352300463-12627-1-git-send-email-kirill.shutemov@linux.intel.com> <1352300463-12627-12-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1133 Lines: 24 On 11/14/2012 03:41 PM, David Rientjes wrote: > > Nobody is going to know what hzp_ is, sorry. It's better to be more > verbose and name them what they actually are: THP_ZERO_PAGE_ALLOC and > THP_ZERO_PAGE_ALLOC_FAILED. But this would assume we want to lazily > allocate them, which I disagree with hpa about. > You want to permanently sit on 2 MiB of memory on all systems? That being an obvious nonstarter, then you end up having to make some kind of static control, with all the problems that entails (if Linus had not set his foot down on tunables a long time ago, we today would have had a Linux mm which only performed well if you manually set hundreds or thousands of parameters) you either have lazy allocation or you go with the virtual huge zero page solution and just accept that either is going to perform poorly under some set of pathological circumstances. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/