From patchwork Thu May 14 03:12:37 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lance Tagliapietra X-Patchwork-Id: 23688 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n4E3qvQ3011809 for ; Thu, 14 May 2009 03:52:57 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754552AbZENDw2 (ORCPT ); Wed, 13 May 2009 23:52:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762453AbZENDw2 (ORCPT ); Wed, 13 May 2009 23:52:28 -0400 Received: from spamtitan.hbci.com ([206.230.105.6]:62489 "EHLO spamtitan.hbci.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761716AbZENDw1 (ORCPT ); Wed, 13 May 2009 23:52:27 -0400 X-Greylist: delayed 457 seconds by postgrey-1.27 at vger.kernel.org; Wed, 13 May 2009 23:52:27 EDT Received: from localhost (localhost [127.0.0.1]) by spamtitan.hbci.com (Postfix) with ESMTP id 3A6B1A185B2; Wed, 13 May 2009 22:44:50 -0500 (CDT) X-Virus-Scanned: by SpamTitan at hbci.com Received: from mail.hbci.com (ultra.hbci.com [206.230.105.5]) by spamtitan.hbci.com (Postfix) with ESMTP id CAE47A1845B; Wed, 13 May 2009 22:44:48 -0500 (CDT) Received: from tag1amiga.luminet.net (unknown [64.213.220.3]) by mail.hbci.com (Postfix) with ESMTP id 5C38E278089; Wed, 13 May 2009 22:44:49 -0500 (CDT) Received: from lancetag by tag1amiga.luminet.net with local (Exim 3.36 #1 (Debian)) id 1M4RN8-00019c-00; Wed, 13 May 2009 22:12:39 -0500 Date: Wed, 13 May 2009 22:12:37 -0500 From: Lance Tagliapietra To: Sam Ravnborg Cc: Geert Uytterhoeven , linux-m68k@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: Re: eliminate -pipe from kernel compile Message-ID: <20090514031235.GA4178@luminet.net> Reply-To: lancetag@Luminet.net Mail-Followup-To: Sam Ravnborg , Geert Uytterhoeven , linux-m68k@vger.kernel.org, linux-kbuild@vger.kernel.org References: <20090511015831.GB15777@luminet.net> <10f740e80905102302gbed0737y61c31900564ca704@mail.gmail.com> <20090513003829.GA13155@uranus.ravnborg.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20090513003829.GA13155@uranus.ravnborg.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Hello, I just completed a test build with my patch to arch/m68k/Makefile to remove the -pipe flag (see patch below). Watching the build confirmed that a) -pipe was no longer showing up in the gcc command lines and b) temporary files were being created as expected without pipe; and c) the as command was not loaded waiting for cc1 to complete. Yea! The /arch/m68k/Makefile is the only place where the -pipe flag is located, and that seems to be the place for all arch's. Pulling out the -pipe does seem to cut compile time. I am working on hard numbers. --Lance On Wed, May 13, 2009 at 02:38:29AM +0200, Sam Ravnborg wrote: > On Mon, May 11, 2009 at 08:02:16AM +0200, Geert Uytterhoeven wrote: > > Added linux-kbuild > > > > On Mon, May 11, 2009 at 03:58, Lance Tagliapietra wrote: > > > I was noticing that kernel compiling is set up to have gcc pipe data from one pass to another, instead of using > > > temporary files. ?On a memory constrained environment, this may not be the best idea (or at least I'd like to > > > explore that idea). ?Instead of loading the assember, and having immediately being swapped out while the cc1 pass > > > runs, it may make more sense to have the temp files being written, instead of the swap in and out, when compiling > > > the various objects of the kernel. > > > > > > So, simply pulling out the -pipe from the compiler flag list didn't see to have the desired effect. ?I'm afraid I'm > > > still missing something. ?I'm still observing the assembler being loaded. > > 1) How did you "pulling out the -pipe from the compiler flag list"? > Please show this as a patch. > > 2) Did you verify that -pipe was used before and no more after your > changes? > Hint - use "make V=1" to see all command line options to gcc > > Sam --- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- arch/m68k/Makefile.old 2009-05-13 21:58:28.000000000 -0500 +++ arch/m68k/Makefile 2009-05-09 11:16:39.000000000 -0500 @@ -33,7 +33,9 @@ CHECKFLAGS += -D__mc68000__ # without -fno-strength-reduce the 53c7xx.c driver fails ;-( -KBUILD_CFLAGS += -pipe -fno-strength-reduce -ffixed-a2 +# delete -pipe to save RAM / minimize swap during compile +# original: KBUILD_CFLAGS += -pipe -fno-strength-reduce -ffixed-a2 +KBUILD_CFLAGS += -fno-strength-reduce -ffixed-a2 # enable processor switch if compiled only for a single cpu ifndef CONFIG_M68020