Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760051AbXEVXlp (ORCPT ); Tue, 22 May 2007 19:41:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757510AbXEVXlj (ORCPT ); Tue, 22 May 2007 19:41:39 -0400 Received: from homer.mvista.com ([63.81.120.158]:63529 "EHLO gateway-1237.mvista.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756706AbXEVXli (ORCPT ); Tue, 22 May 2007 19:41:38 -0400 Subject: Re: [PATCH -rt] ARM TLB flush fix: don't forget to re-enable preemption From: Kevin Hilman To: Daniel Walker Cc: Ingo Molnar , linux-kernel@vger.kernel.org In-Reply-To: <1179876320.15427.214.camel@imap.mvista.com> References: <20070522230128.891568116@mvista.com> <1179876320.15427.214.camel@imap.mvista.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Tue, 22 May 2007 16:41:36 -0700 Message-Id: <1179877296.6122.74.camel@vence.hilman.org> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1245 Lines: 34 On Tue, 2007-05-22 at 16:25 -0700, Daniel Walker wrote: > On Tue, 2007-05-22 at 16:01 -0700, Kevin Hilman wrote: > > Add a preempt_enable() to flush_tlb_kernel_page() since -rt4 patch > > adds a preempt_disable but no preempt_enable(). > > > > Signed-off-by: Kevin Hilman > > > > > > --- > > include/asm-arm/tlbflush.h | 1 + > > 1 file changed, 1 insertion(+) > > > > Index: linux-2.6.21/include/asm-arm/tlbflush.h > > =================================================================== > > --- linux-2.6.21.orig/include/asm-arm/tlbflush.h > > +++ linux-2.6.21/include/asm-arm/tlbflush.h > > @@ -378,6 +378,7 @@ static inline void local_flush_tlb_kerne > > asm("mcr p15, 0, %0, c8, c6, 1" : : "r" (kaddr) : "cc"); > > if (tlb_flag(TLB_V6_I_PAGE)) > > asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (kaddr) : "cc"); > > Aren't these mcr operations atomic? > Individually, yes. But the point of the preempt_disable/enable is to make the whole sequence atomic. Kevin - 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/