From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from i-194-106-37-22.freedom2surf.net ([194.106.37.22]:5760 "EHLO shirehall.home.oldelvet.org.uk") by vger.kernel.org with ESMTP id S267272AbUHOXrS (ORCPT ); Sun, 15 Aug 2004 19:47:18 -0400 Subject: Re: Using get_cycles for add_timer_randomness From: Richard Mortimer In-Reply-To: <20040815154821.2d6edb03.akpm@osdl.org> References: <200308160303.17612.arnd@arndb.de> <20040810162435.GK24690@krispykreme> <20040814183623.GB5637@krispykreme> <20040815154821.2d6edb03.akpm@osdl.org> Content-Type: text/plain Message-Id: <1092613609.4169.22.camel@duncow> Mime-Version: 1.0 Date: Mon, 16 Aug 2004 00:46:50 +0100 Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: richm@oldelvet.org.uk, Anton Blanchard , arnd@arndb.de, tytso@mit.edu, linux-arch@vger.kernel.org List-ID: On Sun, 2004-08-15 at 23:48, Andrew Morton wrote: > Things have changed a bit - sparc now has special-case code in there too. > Hopefully we can remove that now. That came from Dave M & me before Anton remembered Arnd's patch. It can be removed with the new patch applied. > Is everyone OK with this? I certainly am. I have tried the patch on sparc64 (albeit on 2.4.26) and get similar results to Anton. Richard > > From: Anton Blanchard > > I tested how long it took to do a dd from /dev/random on ppc64 before and > after this patch, while doing a ping flood from another machine. > > before: > # /usr/bin/time dd if=/dev/random of=/dev/zero count=1k > 0+51 records in > Command terminated by signal 2 > 0.00user 0.00system 19:18.46elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k > > I gave up after 19 minutes. > > after: > # /usr/bin/time dd if=/dev/random of=/dev/zero count=1k > 0+1024 records in > 0.00user 0.00system 0:33.38elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k > > Just over 33 seconds. Better. > _ -- richm@oldelvet.org.uk