From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 778C06B01EB for ; Thu, 3 Jun 2010 02:51:43 -0400 (EDT) Received: by bwz1 with SMTP id 1so172146bwz.14 for ; Wed, 02 Jun 2010 23:51:41 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20100531165528.35a323fb.rdunlap@xenotime.net> <4C047CF9.9000804@tmr.com> <20100601123959.747228c6.rdunlap@xenotime.net> Date: Thu, 3 Jun 2010 09:51:41 +0300 Message-ID: Subject: Re: Possible bug in 2.6.34 slub From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Randy Dunlap , Giangiacomo Mariotti , Bill Davidsen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86 maintainers , Ingo Molnar , "H. Peter Anvin" List-ID: On Tue, Jun 1, 2010 at 10:48 PM, Christoph Lameter wrote: > On Tue, 1 Jun 2010, Randy Dunlap wrote: > >> > >>> My cpu is an I7 920, so it has 4 cores and there's hyperthreading >> > >>> enabled, so there are 8 logical cpus. Is this a bug? > > Yes its a bug in the arch code or BIOS. The system configuration tells us > that there are more possible cpus and therefore the system prepares for > the additional cpus to be activated at some later time. I guess we should CC x86 maintainers then! >> Sorry, I think that I misread your report. >> It does look like misinformation. >> Let's cc Christoph Lameter & Pekka. >> >> >> > The point is, I guess(didn't actually look at the code), if that's >> > just the count of MAX number of cpus supported, which is a config time >> > =A0define and then the actual count gets refined afterwards by slub >> > too(because I know that the rest of the kernel knows I've got 4 >> > cores/8 logical cpus) or not. Is that it? If this is not the case(that >> > is, it's not a static define used as a MAX value), then I can't see >> > what kind of boot/init time info it is. If it's a boot-time info, it >> > just means it's a _wrong_ boot-time info. > > No that is the max nr of cpus possible on this machine. The count is > determined by hardware capabilities on bootup. If they are not detected > in the right way then you have the erroneous display (and the system > configures useless per cpu structures to support nonexistent cpus). -- 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: email@kvack.org