From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753569Ab1DMM42 (ORCPT ); Wed, 13 Apr 2011 08:56:28 -0400 Received: from mail-vx0-f174.google.com ([209.85.220.174]:61653 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751927Ab1DMM41 (ORCPT ); Wed, 13 Apr 2011 08:56:27 -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=L4xBdU+5pqJXNi3FXJgqtBdE1bi9IJckm3UTkvArtgLncxpWF94KPQYdCRaah/6PX1 rAP0po+0VD9BKQ1nNoJn4mn9nz6iuDzF0upnnA4raQpnmr1L/dJO0DW9hUycE6b3eyyN G0dcDU8cnJSry/0Et0AS5VdGz4MiXZeqinYPQ= MIME-Version: 1.0 In-Reply-To: <1302698512-11979-2-git-send-email-richard@nod.at> References: <1302698512-11979-1-git-send-email-richard@nod.at> <1302698512-11979-2-git-send-email-richard@nod.at> Date: Wed, 13 Apr 2011 15:56:26 +0300 X-Google-Sender-Auth: cQDhSUVD5eE3Lp3MaPteNTQeW48 Message-ID: Subject: Re: [PATCH 2/2] um: Disable CONFIG_CMPXCHG_LOCAL From: Pekka Enberg To: Richard Weinberger Cc: akpm@linux-foundation.com, slyich@gmail.com, linux-kernel@vger.kernel.org, jdike@addtoit.com, user-mode-linux-devel@lists.sourceforge.net, Christoph Lameter , Tejun Heo 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 On Wed, Apr 13, 2011 at 3:41 PM, Richard Weinberger wrote: > Commit 8a5ec0ba "Lockless (and preemptless) fastpaths for slub" > makes use of this_cpu_cmpxchg_double() which needs > this_cpu_cmpxchg16b_emu() on x86_64. > Implementing cmpxchg16b emulation for UML would introduce > too much complexity. So just disable it. > > LKML-Reference: <20110412192014.GF16342@mtj.dyndns.org> > Reported-by: Sergei Trofimovich > Signed-off-by: Richard Weinberger Acked-by: Pekka Enberg