Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752008Ab0AVHYP (ORCPT ); Fri, 22 Jan 2010 02:24:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751934Ab0AVHYP (ORCPT ); Fri, 22 Jan 2010 02:24:15 -0500 Received: from e39.co.us.ibm.com ([32.97.110.160]:34921 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751943Ab0AVHYO (ORCPT ); Fri, 22 Jan 2010 02:24:14 -0500 Date: Fri, 22 Jan 2010 12:54:02 +0530 From: Ananth N Mavinakayanahalli To: Srikar Dronamraju Cc: Ingo Molnar , Peter Zijlstra , utrace-devel , Frederic Weisbecker , Masami Hiramatsu , Maneesh Soni , Jim Keniston , Avi Kivity , Pekka Enberg , Mel Gorman , "Paul E. McKenney" , LKML Subject: Re: [RFC] [PATCH 0/7] UBP, XOL and Uprobes [ Summary of Comments and actions to be taken ] Message-ID: <20100122072402.GA7440@in.ibm.com> Reply-To: ananth@in.ibm.com References: <20100111122521.22050.3654.sendpatchset@srikar.in.ibm.com> <20100122070232.GA2975@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100122070232.GA2975@linux.vnet.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1218 Lines: 27 On Fri, Jan 22, 2010 at 12:32:32PM +0530, Srikar Dronamraju wrote: > Here is a summary of the Comments and actions that need to be taken for > the current uprobes patchset. Please let me know if I missed or > misunderstood any of your comments. > > 1. Uprobes depends on trap signal. > Uprobes depends on trap signal rather than hooking to the global > die notifier. It was suggested that we hook to the global die notifier. > > In the next version of patches, Uprobes will use the global die > notifier and look at the per-task count of the probes in use to > see if it has to be consumed. > > However this would reduce the ability of uprobe handlers to > sleep. Since we are dealing with userspace, sleeping in handlers > would have been a good feature. We are looking at ways to get > around this limitation. We could set a TIF_ flag in the notifier to indicate a breakpoint hit and process it in task context before the task heads into userspace. Ananth -- 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/