Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756627Ab1CXR4h (ORCPT ); Thu, 24 Mar 2011 13:56:37 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:37654 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480Ab1CXR4g (ORCPT ); Thu, 24 Mar 2011 13:56:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=oPTDSvoxHpu62a61on65G+SPPB0v4MCrQjkOwVKMK1xpAtahLqP71Mo6Psmgkfq4td xdhZ5OKzFMwTGpkSA5iaDKgwjc5LeeCfoZrd3HM00NRaTguPGx7K/DX5Q5PWUinP4bwx YMMoeegW/crXEPbVhqpSTKtdbhdIgTzvA0R1s= MIME-Version: 1.0 In-Reply-To: References: <20110324142146.GA11682@elte.hu> <20110324172653.GA28507@elte.hu> Date: Thu, 24 Mar 2011 19:56:35 +0200 X-Google-Sender-Auth: jYAvL6fE08xpA-QjGEDlQm7Esk4 Message-ID: Subject: Re: [GIT PULL] SLAB changes for v2.6.39-rc1 From: Pekka Enberg To: Christoph Lameter Cc: Ingo Molnar , torvalds@linux-foundation.org, akpm@linux-foundation.org, tj@kernel.org, npiggin@kernel.dk, rientjes@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1424 Lines: 29 On Thu, 24 Mar 2011, Ingo Molnar wrote: >> > How does alternative_io() work? Does it require >> > alternative_instructions() to be executed. If so, the fallback code >> > won't be active when we enter kmem_cache_init(). Is there any reason >> > check_bugs() is called so late during boot? Can we do something like >> > the totally untested attached patch? >> >> Does the config i sent you boot on your box? I think the bug is pretty generic >> and should trigger on any box. On Thu, Mar 24, 2011 at 7:43 PM, Christoph Lameter wrote: > The bug should only trigger on old AMD64 boxes that do not support > cmpxchg16b. Yup. Ingo is it possible to see /proc/cpuinfo of one of the affected boxes? I'll try your config but I'm pretty sure the problem doesn't trigger here. Like I said, I think the problem is that alternative instructions are not patched early enough for cmpxchg16b emulation to work for kmem_cache_init(). I tried my check_bugs() patch but it hangs during boot. I'll see if I can cook up a patch that does alternative_instructions() before kmem_cache_init() because I think those *should* be available during boot too. Pekka -- 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/