From owner-freebsd-arch@FreeBSD.ORG Wed Mar 23 11:52:06 2011 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A151B106564A; Wed, 23 Mar 2011 11:52:06 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 82AD98FC08; Wed, 23 Mar 2011 11:52:05 +0000 (UTC) Received: from porto.topspin.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id NAA06851; Wed, 23 Mar 2011 13:51:23 +0200 (EET) (envelope-from avg@freebsd.org) Received: from localhost.topspin.kiev.ua ([127.0.0.1]) by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1Q2Maw-000EOc-P6; Wed, 23 Mar 2011 13:51:22 +0200 Message-ID: <4D89DEB9.7060509@freebsd.org> Date: Wed, 23 Mar 2011 13:51:21 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.15) Gecko/20110308 Lightning/1.0b2 Thunderbird/3.1.9 MIME-Version: 1.0 To: Matthew Jacob References: <201103221551.14289.jhb@freebsd.org> <4D88FE89.1060900@feral.com> In-Reply-To: <4D88FE89.1060900@feral.com> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Bjoern A. Zeeb" , freebsd-arch@freebsd.org Subject: Re: kernel memory checks on boot vs. boot time X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Mar 2011 11:52:06 -0000 on 22/03/2011 21:54 Matthew Jacob said the following: > John Baldwin wrote: >> >> Do other platforms bother with these sorts of memory tests? If not I'd vote >> to just drop it. I think this mattered more when you didn't have things like >> SMAP (so you had to guess at where memory ended sometimes). Also, modern >> server class x86 machines generally support ECC RAM which will trigger a >> machine check if there is a problem. I doubt that the early checks are >> catching anything even for the non-ECC case. >> >> If nothing else, I would definitely drop this from amd64 (all those systems >> have SMAP and machine check support, etc.). >> >> > Memory checks are definitely still useful. Loading the linux mem tester has > helped find lots of problems, even on so-called modern machines. I'd voter for > leaving this as an option. I think that you talk about a different kind of memory checking/testing. What we have in FreeBSD looks a lot like what BIOSes use(d) to do on startup. Besides, AFAIR, it doesn't report any results to you. -- Andriy Gapon