From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Date: Mon, 18 Oct 2004 18:06:45 +0000 Subject: Re: [PATCH] General purpose zeroed page slab Message-Id: List-Id: References: <20041014180427.GA7973@wotan.suse.de> In-Reply-To: <20041014180427.GA7973@wotan.suse.de> (Andi Kleen's message of "Thu, 14 Oct 2004 20:04:27 +0200") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andi Kleen Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, akpm@osdl.org, tony.luck@intel.com >>>>> "Andi" = Andi Kleen writes: [Sorry about dropping off of the planet for a couple of days. Had to deal with some water damage on the house :/] Andi> The means every user has to memset it to zero before free. Add Andi> a comment for that at least. Andi> Also that's pretty dumb. How about keeping track how much of the Andi> page got non zeroed (e.g. by using a few free words in struct Andi> page for a coarse grained dirty bitmap) Andi> Then you could memset on free only the parts that got actually Andi> changed, and never waste cache lines for anything else. Ayup. I'll ponder this a bit. For now I think I'm going to leave the page table cache stuff as is and make the general purpose slab a separate project. It'll be easy to switch the page tables over later. -- Martin K. Petersen Wild Open Source, Inc. mkp@wildopensource.com http://www.wildopensource.com/ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266684AbUJRSGx (ORCPT ); Mon, 18 Oct 2004 14:06:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267254AbUJRSGw (ORCPT ); Mon, 18 Oct 2004 14:06:52 -0400 Received: from vanessarodrigues.com ([192.139.46.150]:45030 "EHLO jaguar.mkp.net") by vger.kernel.org with ESMTP id S266684AbUJRSGs (ORCPT ); Mon, 18 Oct 2004 14:06:48 -0400 To: Andi Kleen Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, akpm@osdl.org, tony.luck@intel.com Subject: Re: [PATCH] General purpose zeroed page slab From: "Martin K. Petersen" Organization: Wild Open Source, Inc. References: <20041014180427.GA7973@wotan.suse.de> Date: Mon, 18 Oct 2004 14:06:45 -0400 In-Reply-To: <20041014180427.GA7973@wotan.suse.de> (Andi Kleen's message of "Thu, 14 Oct 2004 20:04:27 +0200") Message-ID: User-Agent: Gnus/5.1006 (Gnus v5.10.6) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Andi" == Andi Kleen writes: [Sorry about dropping off of the planet for a couple of days. Had to deal with some water damage on the house :/] Andi> The means every user has to memset it to zero before free. Add Andi> a comment for that at least. Andi> Also that's pretty dumb. How about keeping track how much of the Andi> page got non zeroed (e.g. by using a few free words in struct Andi> page for a coarse grained dirty bitmap) Andi> Then you could memset on free only the parts that got actually Andi> changed, and never waste cache lines for anything else. Ayup. I'll ponder this a bit. For now I think I'm going to leave the page table cache stuff as is and make the general purpose slab a separate project. It'll be easy to switch the page tables over later. -- Martin K. Petersen Wild Open Source, Inc. mkp@wildopensource.com http://www.wildopensource.com/