From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752802AbYDNJwj (ORCPT ); Mon, 14 Apr 2008 05:52:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751146AbYDNJwa (ORCPT ); Mon, 14 Apr 2008 05:52:30 -0400 Received: from pasmtpa.tele.dk ([80.160.77.114]:46183 "EHLO pasmtpA.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbYDNJw3 (ORCPT ); Mon, 14 Apr 2008 05:52:29 -0400 Date: Mon, 14 Apr 2008 11:52:59 +0200 From: Sam Ravnborg To: Jacek Luczak Cc: Ingo Molnar , LKML Subject: Re: [PATCH] x86: pgtable_32.h - prototype and section mismatch fixes Message-ID: <20080414095259.GA11966@uranus.ravnborg.org> References: <48022990.3060104@gmail.com> <20080414072645.GG16163@elte.hu> <20080414084127.GA11372@uranus.ravnborg.org> <20080414085307.GG19865@elte.hu> <20080414085927.GC11372@uranus.ravnborg.org> <48031FA7.9050803@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48031FA7.9050803@gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 14, 2008 at 11:11:03AM +0200, Jacek Luczak wrote: > Sam Ravnborg pisze: > > On Mon, Apr 14, 2008 at 10:53:07AM +0200, Ingo Molnar wrote: > >> * Sam Ravnborg wrote: > >> > >>>> hm, that's an interesting case: we need those annotations probably > >>>> because gcc decided to not inline those functions. (this is possible > >>>> via the new CONFIG_OPTIMIZE_INLINING=y option) Sam, what's your take > >>>> on that? > >>> gcc uses different heuristics for inlining between the different > >>> versions. Therefore to achieve somehow predictable results I added > >>> -fno-inline-functions-called-once when CONFIG_DEBUG_SECTION_MISMATCH > >>> is enabled. > >>> > >>> So in the above case for any normal kernel build we would see that gcc > >>> inlined the above and everything is fine. But for the > >>> CONFIG_DEBUG_SECTION_MISMTCH cases we do not inline and thus we see > >>> that we have a section mismatch. > >> ah, ok. So i guess this will result in a few isolated cases of __init > >> annotations added to inline functions - Jacek fixed one such case - but > >> it should not result in the general spreading of __init annotations to > >> inline functions, correct? (which i was worried about) > > I do not think so. The need for small isolated inline functions > > in the init paths are minimal and last I did a section mismatch free > > sweep on the kernel it was only few if any inline functions(*) I had > > to annotate. > > > > (*) Considering only the minimal amount of function that ought > > to be annotated inlined. > > There's a lot of inline __init functions already - which, on the other hand > should not result in more of such. Attached you can find grep on tree which > shows all inline __init functions (you won't find my paravirt_pagetable_setup_* > functions in output as I removed __init for test). Most of the functionas listed should never have been annotated inline. If you filter aways the functions that are in one one of their incarnations longer than 8 lines or are located in a .c file the list is much shorter. This is the real candidates (the figure '8' is just bad way to filter away 'complex' functions). Your paravirt_pagetable_setup_done is a real one btw. > Sam, do -fno-inline-functions-called-once could affect > paravirt_pagetable_setup_done? In general there was no section mismatch warning > for this function, but I've annotated it also. Most liekly yes - but I did not check. Sam