From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761882AbYD0RH1 (ORCPT ); Sun, 27 Apr 2008 13:07:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754740AbYD0RHV (ORCPT ); Sun, 27 Apr 2008 13:07:21 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51917 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753825AbYD0RHU (ORCPT ); Sun, 27 Apr 2008 13:07:20 -0400 Date: Sun, 27 Apr 2008 10:06:41 -0700 (PDT) From: Linus Torvalds To: Adrian Bunk cc: Sam Ravnborg , linux arch , LKML , Ingo Molnar , David Miller Subject: Re: [PATCH] prepare kconfig inline optimization for all architectures In-Reply-To: <20080427113158.GY2252@cs181133002.pp.htv.fi> Message-ID: References: <20080427105100.GA14795@uranus.ravnborg.org> <20080427113158.GY2252@cs181133002.pp.htv.fi> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) 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 Sun, 27 Apr 2008, Adrian Bunk wrote: > > My opinion on this is still: > "OPTIMIZE" means "work around bugs in the kernel". No. It means that - gcc used to (long ago) always honor "inline", and we had kernel code that depended on that in various ways (ie required that there was no return etc). We've been mostly replacing the ones we know about with "__always_inline", but there may be some that remain. We'll find out, I guess. - gcc was a total and utter piece of horrible crap in the inlining department, doign insane things and changing their documentation to match the new behaviour (and some people then claimed that it was always documented that way). It would not inline big functions even when they statically collapsed to nothing, etc. As a result, we really couldn't afford to let gcc make any inlining decisions, because the compiler was simply *broken*. Linus