From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756561Ab3GKTXW (ORCPT ); Thu, 11 Jul 2013 15:23:22 -0400 Received: from cantor2.suse.de ([195.135.220.15]:59510 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751610Ab3GKTXV (ORCPT ); Thu, 11 Jul 2013 15:23:21 -0400 Date: Thu, 11 Jul 2013 21:23:20 +0200 (CEST) From: Jiri Kosina To: Steven Rostedt Cc: Jason Baron , Masami Hiramatsu , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , mathieu.desnoyers@efficios.com Subject: Re: [RFC] [PATCH 0/2] x86: make jump labels use int3-based breakpoint instead of stop_machine() In-Reply-To: <1373560944.17876.41.camel@gandalf.local.home> Message-ID: References: <51DDDFB3.3020004@akamai.com> <1373560944.17876.41.camel@gandalf.local.home> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 11 Jul 2013, Steven Rostedt wrote: > On Thu, 2013-07-11 at 02:04 +0200, Jiri Kosina wrote: > > > I even have preliminary (completely untested) patch, but would like to > > have this merged/acked in the first round before proceeding with porting > > ftrace to the new interface. > > > > > Also, I wonder if its worth batching up updates. For example, right now > > > we simply update each call-site one at a time even if its associated > > > with the same control variable. > > > > That does seem to make sense indeed, but it's not really closely tied to > > this patchset, is it? > > If you want to have ftrace use this interface, then we need to support > batch processing. And you will need to do it with an iterator as well. > We can not allocate 30,000 locations to run this on. Ftrace has its own > table, and uses the ftrace iterator to traverse it. > > Thus you would need to do something like: Yup, I have been looking at the ftrace implementation and came to this conclusion; thanks for confirmation. That's exactly why I wanted to postpone converting ftrace before agreement on text_poke_bp() is reached and jump labels are converted. Thanks, -- Jiri Kosina SUSE Labs