Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757255Ab0FNXPG (ORCPT ); Mon, 14 Jun 2010 19:15:06 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:34185 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751201Ab0FNXPC (ORCPT ); Mon, 14 Jun 2010 19:15:02 -0400 Subject: Re: [PATCH 1/5] vmlinux.lds.h: Include *(.text.*) in TEXT_TEXT From: James Bottomley To: Tim Abbott Cc: Matt Fleming , linux-arch@vger.kernel.org, Arnd Bergmann , linux-kernel@vger.kernel.org, Sam Ravnborg , Michal Marek , Denys Vlasenko , linux-parisc@vger.kernel.org In-Reply-To: References: <1276519112-11649-1-git-send-email-matt@console-pimps.org> <87y6ehxvby.fsf@linux-g6p1.site> Content-Type: text/plain; charset="UTF-8" Date: Mon, 14 Jun 2010 18:14:59 -0500 Message-ID: <1276557299.5374.847.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1618 Lines: 37 On Mon, 2010-06-14 at 18:21 -0400, Tim Abbott wrote: > On Mon, 14 Jun 2010, Matt Fleming wrote: > > > Do these special kernel sections include things like the parisc > > .text.do_softirq, .text.sys_exit, etc? James raised a good objection to > > the parisc patch of this series. I'm guessing most people saw it already > > but I'll paste it here for reference, > > > > This would destroy all of the named parisc text ordering we do above the > > removed line because now you'd have swept up all the function sections > > before we get to them, won't it? > > > > The ordering is an execution speed up on 32 bit systems because our > > relative jump is so short. > > > > Will you changes handle this OK? > > I think I addressed this in my reply to James just now, but to be super > clear, this -ffunction-sections plan involves renaming .text.do_softirq to > .text..do_softirq (etc.) first. OK, so that doesn't make a lot of sense to me; I suspect because you don't understand what parisc is doing. These aren't names of linux special sections ... they're names of function sections. For efficiency, we take specific hot functions and place them together in the linker script so the jumps between them are small enough to be coded as relative on the 32 bit architecture. It's really just a more efficient way of laying out the binary. James -- 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/