Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755766Ab3JRPBb (ORCPT ); Fri, 18 Oct 2013 11:01:31 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.226]:17193 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751069Ab3JRPB3 (ORCPT ); Fri, 18 Oct 2013 11:01:29 -0400 Date: Fri, 18 Oct 2013 11:01:28 -0400 From: Steven Rostedt To: Steven Rostedt Cc: Petr Mladek , Frederic Weisbecker , Masami Hiramatsu , Jiri Kosina , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH 5/6] x86: patch all traced function calls using the int3-based framework Message-ID: <20131018110128.7033ce4c@gandalf.local.home> In-Reply-To: <20131018105557.0961a2f5@gandalf.local.home> References: <1382106445-31468-6-git-send-email-pmladek@suse.cz> <20131018105557.0961a2f5@gandalf.local.home> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1496 Lines: 39 On Fri, 18 Oct 2013 10:55:57 -0400 Steven Rostedt wrote: > On Fri, 18 Oct 2013 16:27:24 +0200 > Petr Mladek wrote: > > > > +/* > > + * We do not want to replace ftrace calls one by one because syncing all CPUs > > + * is quite expensive. > > + * > > + * On the other hand, we do not want to modify all calls at once because > > + * the buffers for text_poke_bp might be quite huge. Also we do not want > > + * to count the number of records before the allocation. > > + * > > + * Let's modify the call in batches defined by this define. > > + */ > > +#define FTRACE_MAX_RECS_PATCH 8192 > > > > -static int finish_update(struct dyn_ftrace *rec, int enable) > > +static int ftrace_allocate_replace_buffers(unsigned long **addr, void **opcode) > > I absolutely hate this. Current ftrace conversion does not need to > allocate at all. I want to keep it that way. > I should clarify that I do not hate the patch set. I actually like what it's trying to achieve (a lot!). But I absolutely hate having to copy records to do the bulk conversion. That part I'm giving a NAK to. Add a text_poke_bp_iterate() or something, that removes the need for allocating extra buffers, then I'll be very happy :-) -- Steve -- 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/