From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262589AbVA0MPi (ORCPT ); Thu, 27 Jan 2005 07:15:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262594AbVA0MPi (ORCPT ); Thu, 27 Jan 2005 07:15:38 -0500 Received: from canuck.infradead.org ([205.233.218.70]:15371 "EHLO canuck.infradead.org") by vger.kernel.org with ESMTP id S262589AbVA0MPe (ORCPT ); Thu, 27 Jan 2005 07:15:34 -0500 Subject: Re: A scrub daemon (prezeroing) From: David Woodhouse To: Christoph Lameter Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: References: Content-Type: text/plain Date: Thu, 27 Jan 2005 12:15:24 +0000 Message-Id: <1106828124.19262.45.camel@hades.cambridge.redhat.com> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-3.dwmw2.1) Content-Transfer-Encoding: 7bit X-Spam-Score: 0.0 (/) X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2005-01-21 at 12:29 -0800, Christoph Lameter wrote: > Adds management of ZEROED and NOT_ZEROED pages and a background daemon > called scrubd. scrubd is disabled by default but can be enabled > by writing an order number to /proc/sys/vm/scrub_start. If a page > is coalesced of that order or higher then the scrub daemon will > start zeroing until all pages of order /proc/sys/vm/scrub_stop and > higher are zeroed and then go back to sleep. Some architectures tend to have spare DMA engines lying around. There's no need to use the CPU for zeroing pages. How feasible would it be for scrubd to use these? -- dwmw2 From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: A scrub daemon (prezeroing) From: David Woodhouse In-Reply-To: References: Content-Type: text/plain Date: Thu, 27 Jan 2005 12:15:24 +0000 Message-Id: <1106828124.19262.45.camel@hades.cambridge.redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Fri, 2005-01-21 at 12:29 -0800, Christoph Lameter wrote: > Adds management of ZEROED and NOT_ZEROED pages and a background daemon > called scrubd. scrubd is disabled by default but can be enabled > by writing an order number to /proc/sys/vm/scrub_start. If a page > is coalesced of that order or higher then the scrub daemon will > start zeroing until all pages of order /proc/sys/vm/scrub_stop and > higher are zeroed and then go back to sleep. Some architectures tend to have spare DMA engines lying around. There's no need to use the CPU for zeroing pages. How feasible would it be for scrubd to use these? -- dwmw2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org