From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758587AbZKYKu6 (ORCPT ); Wed, 25 Nov 2009 05:50:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755669AbZKYKu5 (ORCPT ); Wed, 25 Nov 2009 05:50:57 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:46994 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752148AbZKYKu5 (ORCPT ); Wed, 25 Nov 2009 05:50:57 -0500 Date: Wed, 25 Nov 2009 11:50:04 +0100 From: Ingo Molnar To: Stephen Rothwell , Fr??d??ric Weisbecker , Peter Zijlstra Cc: Tejun Heo , Rusty Russell , Christoph Lameter , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: linux-next: percpu tree build warning Message-ID: <20091125105004.GA18163@elte.hu> References: <20091125214219.f37935e8.sfr@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091125214219.f37935e8.sfr@canb.auug.org.au> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=none autolearn=no SpamAssassin version=3.2.5 _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Stephen Rothwell wrote: > Hi all, > > Today's linux-next build (x86_64 allmodconfig) produced this warning: > > arch/x86/kernel/hw_breakpoint.c: In function 'arch_install_hw_breakpoint': > arch/x86/kernel/hw_breakpoint.c:121: warning: assignment from incompatible pointer type > arch/x86/kernel/hw_breakpoint.c: In function 'arch_uninstall_hw_breakpoint': > arch/x86/kernel/hw_breakpoint.c:156: warning: assignment from incompatible pointer type > > I am not sure where this one came from ... the code does: DEFINE_PER_CPU(unsigned long, dr7); int arch_install_hw_breakpoint(struct perf_event *bp) { ... unsigned long *dr7; ... dr7 = &__get_cpu_var(dr7); ... } Tejun, is it perhaps a problem of the percpu code getting confused between the local and file scope 'dr7' variable shadowing each other? If yes then that needs to be fixed in the percpu tree. per-cpu variables used to have a __per_cpu prefix and that should be maintained - the two namespaces are obviously separate on the logical space, so they should never overlap in the implementational space either. Ingo