Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757469AbYJRAJT (ORCPT ); Fri, 17 Oct 2008 20:09:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756512AbYJRAJF (ORCPT ); Fri, 17 Oct 2008 20:09:05 -0400 Received: from mx1.redhat.com ([66.187.233.31]:53762 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756508AbYJRAJF (ORCPT ); Fri, 17 Oct 2008 20:09:05 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Alan Stern X-Fcc: ~/Mail/linus Cc: prasad@linux.vnet.ibm.com, Linux Kernel Mailing List , , , , , Subject: Re: [RFC Patch 6/9] Use virtual debug registers in process/thread handling code In-Reply-To: Alan Stern's message of Thursday, 16 October 2008 10:27:03 -0400 References: <20081016014407.81BDA1544CB@magilla.localdomain> X-Antipastobozoticataclysm: Bariumenemanilow Message-Id: <20081018000829.519111544CB@magilla.localdomain> Date: Fri, 17 Oct 2008 17:08:29 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1006 Lines: 23 > There's a problem with moving the switch_to_thread_hw_breakpoint() call > before current is updated. [...] I got this. I'm just saying let's look for ways to do this better. Hmm. The 64-bit version of __switch_to does the current change much earlier, before __switch_to_xtra and math_state_restore. I wonder if the 32-bit version could change to match. I can't see what in __switch_to_xtra would care either way, though I may be overlooking something. Ingo? If this does not change, then __switch_to_xtra can pass prev,next to switch_hw_breakpoint. You can always do some slightly different bookkeeping in there to know that prev->next is the switch happening, so if there is a hit when current still == prev you can filter it out. Thanks, Roland -- 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/