From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751428Ab2AZNz3 (ORCPT ); Thu, 26 Jan 2012 08:55:29 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:55321 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751383Ab2AZNz2 (ORCPT ); Thu, 26 Jan 2012 08:55:28 -0500 Date: Thu, 26 Jan 2012 14:55:04 +0100 From: Ingo Molnar To: Steven Rostedt Cc: Rusty Russell , LKML , Andrew Morton , Frederic Weisbecker Subject: Re: [RFC][PATCH] tracing/module: Move tracepoint out of module.h Message-ID: <20120126135504.GA13107@elte.hu> References: <1326754637.7642.177.camel@gandalf.stny.rr.com> <20120117095418.GG10397@elte.hu> <1326807145.17534.26.camel@gandalf.stny.rr.com> <20120118120711.GB14863@elte.hu> <1326909412.17534.91.camel@gandalf.stny.rr.com> <877h0jgx80.fsf@rustcorp.com.au> <1327545664.22710.78.camel@gandalf.stny.rr.com> <20120126102836.GD3853@elte.hu> <1327585945.22710.87.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1327585945.22710.87.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > On Thu, 2012-01-26 at 11:28 +0100, Ingo Molnar wrote: > > > How much more do we save if we move all of try_module_get() out > > of line? It still seems a rather thick inline function with > > preempt section and all. I'd *really* suggest that it should all > > be uninlined. > > > > Here's the #'s > > text data bss dec hex filename > 7489488 2249584 9719808 19458880 128eb40 vmlinux-prepatch > text data bss dec hex filename > 7482458 2248048 9719808 19450314 128c9ca vmlinux-postpatch > text data bss dec hex filename > 7477393 2248080 9719808 19445281 128b621 vmlinux-updatedpatch > > Thus we get an additional 5k it seems, for a total of 13k savings. > > The below patch is what I used. Note, since the tracepoint > requires the instruction pointer, I created stub versions that > call a "do_" version of the function to pass in the local > instruction counter. Hm, why does this tracepoint include a flat RIP? It's pretty superfluous as there's various other (orghogonal) ways to get at the RIP. If the field is needed for compatibility then lets set it to zero at the tracepoint level and not burden the module.h hotpath. Thanks, Ingo