Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264134AbUCZVMi (ORCPT ); Fri, 26 Mar 2004 16:12:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264135AbUCZVMi (ORCPT ); Fri, 26 Mar 2004 16:12:38 -0500 Received: from palrel13.hp.com ([156.153.255.238]:46208 "EHLO palrel13.hp.com") by vger.kernel.org with ESMTP id S264134AbUCZVMg (ORCPT ); Fri, 26 Mar 2004 16:12:36 -0500 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16484.40129.606865.830739@napali.hpl.hp.com> Date: Fri, 26 Mar 2004 13:12:33 -0800 To: Andrew Morton Cc: davidm@hpl.hp.com, davidm@napali.hpl.hp.com, davej@redhat.com, mpm@selenic.com, linux-kernel@vger.kernel.org Subject: Re: Fw: potential /dev/urandom scalability improvement In-Reply-To: <20040326123303.7a775b02.akpm@osdl.org> References: <20040325141923.7080c6f0.akpm@osdl.org> <20040325224726.GB8366@waste.org> <16483.35656.864787.827149@napali.hpl.hp.com> <20040325180014.29e40b65.akpm@osdl.org> <20040326110619.GA25210@redhat.com> <16484.29095.842735.102236@napali.hpl.hp.com> <20040326104904.59f7a156.akpm@osdl.org> <16484.37279.839961.375027@napali.hpl.hp.com> <20040326123303.7a775b02.akpm@osdl.org> X-Mailer: VM 7.18 under Emacs 21.3.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 776 Lines: 22 >>>>> On Fri, 26 Mar 2004 12:33:03 -0800, Andrew Morton said: Andrew> If someone does, say, Andrew> prefetch_range(some_pointer, sizeof(*some_pointer)); Andrew> then it is possible that prefetch_range() could Andrew> a) execute a prefetch at addresses which are not Andrew> PREFETCH_STRIDE-aligned and, as a consequence, Andrew> b) prefetch data from the next page, outside the range of Andrew> the user's (addr,len). This is getting silly. Cache-lines _never_ cross page-boundaries. --david - 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/