Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263021AbTIAQeH (ORCPT ); Mon, 1 Sep 2003 12:34:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263040AbTIAQeH (ORCPT ); Mon, 1 Sep 2003 12:34:07 -0400 Received: from mail.jlokier.co.uk ([81.29.64.88]:59273 "EHLO mail.jlokier.co.uk") by vger.kernel.org with ESMTP id S263021AbTIAQeC (ORCPT ); Mon, 1 Sep 2003 12:34:02 -0400 Date: Mon, 1 Sep 2003 17:33:54 +0100 From: Jamie Lokier To: Larry McVoy , Larry McVoy , linux-kernel@vger.kernel.org Subject: Re: x86, ARM, PARISC, PPC, MIPS and Sparc folks please run this Message-ID: <20030901163354.GA3556@mail.jlokier.co.uk> References: <20030829053510.GA12663@mail.jlokier.co.uk> <20030829154101.GB16319@work.bitmover.com> <20030901054413.GF748@mail.jlokier.co.uk> <20030901144304.GA1327@work.bitmover.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030901144304.GA1327@work.bitmover.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2090 Lines: 46 Larry McVoy wrote: > I'm a little concerned I have the wrong test, why would a 2.1Ghz Athlon > say it is too slow? It's the right test. "too slow" means that where shared memory is mapped at a certain separation, alternating accesses between the different virtual addresses are much slower (10-20 times) than if the underlying mapped memory is not shared. All Athlons show this slowdown for any virtual address separation which is not a multiple of 32k. No Intels do, with the possible exception of a P4 which showed inconsistent results and needs further investigation. Your freebsds don't what CPU they are, but let me guess.. freebsd isn't an AMD freebsd3 and freebsd4 are both AMD K6, and freebsd3 is the faster -- Jamie > ==== freebsd ==== > (512) [32,32,1] Test separation: 4096 bytes: pass ... > FreeBSD freebsd.bitmover.com 2.2.8-RELEASE FreeBSD 2.2.8-RELEASE #0: Mon Nov 30 06:34:08 GMT 1998 jkh@time.cdrom.com:/usr/src/sys/compile/GENERIC i386 > ==== freebsd3 ==== > (64) [33,3,1] Test separation: 4096 bytes: FAIL - too slow > (64) [33,3,1] Test separation: 8192 bytes: FAIL - too slow > (512) [19,26,1] Test separation: 16384 bytes: pass > VM page alias coherency test: minimum fast spacing: 16384 (4 pages) > > FreeBSD freebsd3.bitmover.com 3.2-RELEASE FreeBSD 3.2-RELEASE #0: Fri Jun 2 11:34:52 PDT 2000 root@freebsd3.bitmover.com:/usr/src/sys/compile/DAVICOM i386 > > ==== freebsd4 ==== > (256) [92,26,5] Test separation: 4096 bytes: FAIL - too slow > (256) [92,26,5] Test separation: 8192 bytes: FAIL - too slow > (1024) [75,101,5] Test separation: 16384 bytes: pass > VM page alias coherency test: minimum fast spacing: 16384 (4 pages) > > FreeBSD freebsd4.bitmover.com 4.1-RELEASE FreeBSD 4.1-RELEASE #0: Fri Jul 28 14:30:31 GMT 2000 jkh@ref4.freebsd.org:/usr/src/sys/compile/GENERIC i386 - 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/