Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262060AbUJZC4M (ORCPT ); Mon, 25 Oct 2004 22:56:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262162AbUJZC4B (ORCPT ); Mon, 25 Oct 2004 22:56:01 -0400 Received: from holomorphy.com ([207.189.100.168]:55520 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S262060AbUJZCqo (ORCPT ); Mon, 25 Oct 2004 22:46:44 -0400 Date: Mon, 25 Oct 2004 19:43:27 -0700 From: William Lee Irwin III To: Jesse Barnes Cc: Christoph Lameter , "Chen, Kenneth W" , linux-kernel@vger.kernel.org Subject: Re: Hugepages demand paging V2 [0/8]: Discussion and overview Message-ID: <20041026024327.GF17038@holomorphy.com> References: <20041026022322.GD17038@holomorphy.com> <200410251940.30574.jbarnes@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200410251940.30574.jbarnes@sgi.com> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1177 Lines: 25 On Mon, Oct 25, 2004 at 06:26:42PM -0700, Christoph Lameter wrote: >>> - Clearing hugetlb pages is time consuming using clear_highpage in >>> alloc_huge_page. Make it possible to use hw assist via DMA or so there? On Monday, October 25, 2004 7:23 pm, William Lee Irwin III wrote: >> It's possible, but it's been found not to be useful. What has been found >> useful is assistance from much lower-level memory hardware of a kind >> not to be had in any extant mass-manufactured machines. On Mon, Oct 25, 2004 at 07:40:30PM -0700, Jesse Barnes wrote: > Do you have examples? SGI hardware has a so-called 'BTE' (for Block Transfer > Engine) that can arbitrarily zero or copy pages w/o CPU assistance. It's > builtin to the memory controller. Using it to zero the pages has the > advantages of being asyncrhonous and not hosing the CPU cache. That's the same kind of thing, so it apparently has been mass-manufactured. -- wli - 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/