From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932463AbWHYUf0 (ORCPT ); Fri, 25 Aug 2006 16:35:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932464AbWHYUf0 (ORCPT ); Fri, 25 Aug 2006 16:35:26 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:10459 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932463AbWHYUfZ (ORCPT ); Fri, 25 Aug 2006 16:35:25 -0400 Subject: Re: [PATCH 0/4] Compile kernel with -fwhole-program --combine From: David Woodhouse To: Rob Landley Cc: linux-kernel@vger.kernel.org, linux-tiny@selenic.com, devel@laptop.org In-Reply-To: <200608251611.50616.rob@landley.net> References: <1156429585.3012.58.camel@pmac.infradead.org> <1156433068.3012.115.camel@pmac.infradead.org> <200608251611.50616.rob@landley.net> Content-Type: text/plain Date: Fri, 25 Aug 2006 21:35:15 +0100 Message-Id: <1156538115.3038.6.camel@pmac.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 (2.6.3-1.fc5.5.dwmw2.1) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2006-08-25 at 16:11 -0400, Rob Landley wrote: > BusyBox has been doing this for months now: "build at once" is one of our > config options. I'd like to point out that gcc eats needs several hundred > megabytes of ram to do this and you have no useful progress indicator between > starting and ending. But the result is definitely smaller. It isn't that bad when you're only building a few files at a time -- I wouldn't suggest doing it for the whole kernel. And you get a nice progress indicator at the moment -- a new warning about global register variables every time it eats a new file, due to GCC PR27899 :) > We also tell the linker "--sort-common --gc-sections" which may or may not > apply here... We want --gc-sections (which requires -ffunction-sections -fdata-sections to be useful) but that's a separate issue. We were doing it a long time ago for the FR-V kernel; Marcelo has been looking at it recently for other architectures. -- dwmw2