From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Malaterre Subject: Re: [PATCH 4/4] powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected Date: Fri, 20 Apr 2018 22:08:27 +0200 Message-ID: References: <20180420073414.23169-1-npiggin@gmail.com> <20180420073414.23169-5-npiggin@gmail.com> <20180420204104.6e22b136@roar.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20180420204104.6e22b136@roar.ozlabs.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Nicholas Piggin Cc: linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org, linuxppc-dev , Nicolas Pitre List-Id: linux-arch.vger.kernel.org On Fri, Apr 20, 2018 at 12:41 PM, Nicholas Piggin wrote: > On Fri, 20 Apr 2018 12:00:49 +0200 > Mathieu Malaterre wrote: > >> On Fri, Apr 20, 2018 at 9:34 AM, Nicholas Piggin wrote: >> > This requires further changes to linker script to KEEP some tables >> > and wildcard compiler generated sections into the right place. This >> > includes pp32 modifications from Christophe Leroy. >> > >> > When compiling powernv_defconfig with this option: >> > >> > text data bss dec filename >> > 11827621 4810490 1341080 17979191 vmlinux >> > 11752437 4598858 1338776 17690071 vmlinux.dcde >> > >> > Resulting kernel is almost 400kB smaller (and still boots). >> > >> > [ppc32 numbers here] >> >> ^^^ >> >> Do you want somebody else to provide those numbers ? > > If you have a booting kernel, yes some more numbers would be good. I've used /boot/config-4.15.0-2-powerpc from my current debian package. Rebuild master with and without option, boot ok, load/unload module ok. $ size nick/vmlinux.with* text data bss dec hex filename 7386425 2364370 1425432 11176227 aa8923 nick/vmlinux.with 7461457 2475122 1428064 11364643 ad6923 nick/vmlinux.without This is not clear why with option the size of kernel is slightly bigger: $ du -sk nick/vmlinux.with* 124488 nick/vmlinux.with 124004 nick/vmlinux.without > Thanks, > Nick From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f66.google.com ([209.85.218.66]:43658 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750927AbeDTUIt (ORCPT ); Fri, 20 Apr 2018 16:08:49 -0400 MIME-Version: 1.0 In-Reply-To: <20180420204104.6e22b136@roar.ozlabs.ibm.com> References: <20180420073414.23169-1-npiggin@gmail.com> <20180420073414.23169-5-npiggin@gmail.com> <20180420204104.6e22b136@roar.ozlabs.ibm.com> From: Mathieu Malaterre Date: Fri, 20 Apr 2018 22:08:27 +0200 Message-ID: Subject: Re: [PATCH 4/4] powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected Content-Type: text/plain; charset="UTF-8" Sender: linux-arch-owner@vger.kernel.org List-ID: To: Nicholas Piggin Cc: linuxppc-dev , linux-arch@vger.kernel.org, Nicolas Pitre , linux-kbuild@vger.kernel.org Message-ID: <20180420200827.OzItMrZ5cX6k7ViTaHm78BfwJkFj0e1sl5WLgi7zoPk@z> On Fri, Apr 20, 2018 at 12:41 PM, Nicholas Piggin wrote: > On Fri, 20 Apr 2018 12:00:49 +0200 > Mathieu Malaterre wrote: > >> On Fri, Apr 20, 2018 at 9:34 AM, Nicholas Piggin wrote: >> > This requires further changes to linker script to KEEP some tables >> > and wildcard compiler generated sections into the right place. This >> > includes pp32 modifications from Christophe Leroy. >> > >> > When compiling powernv_defconfig with this option: >> > >> > text data bss dec filename >> > 11827621 4810490 1341080 17979191 vmlinux >> > 11752437 4598858 1338776 17690071 vmlinux.dcde >> > >> > Resulting kernel is almost 400kB smaller (and still boots). >> > >> > [ppc32 numbers here] >> >> ^^^ >> >> Do you want somebody else to provide those numbers ? > > If you have a booting kernel, yes some more numbers would be good. I've used /boot/config-4.15.0-2-powerpc from my current debian package. Rebuild master with and without option, boot ok, load/unload module ok. $ size nick/vmlinux.with* text data bss dec hex filename 7386425 2364370 1425432 11176227 aa8923 nick/vmlinux.with 7461457 2475122 1428064 11364643 ad6923 nick/vmlinux.without This is not clear why with option the size of kernel is slightly bigger: $ du -sk nick/vmlinux.with* 124488 nick/vmlinux.with 124004 nick/vmlinux.without > Thanks, > Nick