Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753242AbZIWShD (ORCPT ); Wed, 23 Sep 2009 14:37:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752404AbZIWShA (ORCPT ); Wed, 23 Sep 2009 14:37:00 -0400 Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:50802 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751710AbZIWSg7 (ORCPT ); Wed, 23 Sep 2009 14:36:59 -0400 Date: Wed, 23 Sep 2009 14:36:06 -0400 (EDT) From: Tim Abbott X-X-Sender: tabbott@dr-wily.mit.edu To: Linus Torvalds cc: linux-kernel@vger.kernel.org, Sam Ravnborg Subject: Re: [PATCH 01/13] Optimize the ordering of sections in RW_DATA_SECTION. In-Reply-To: Message-ID: References: <1253629347-23119-1-git-send-email-tabbott@ksplice.com> <1253629347-23119-2-git-send-email-tabbott@ksplice.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Flag: NO X-Spam-Score: 0.00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1764 Lines: 51 On Wed, 23 Sep 2009, Linus Torvalds wrote: > > Umm. As a commit message this sucks. What's so optimized about this? Yeah, it does. Sorry about that. This patch sorts the sections by alignment requirements, which should pack them essentially optimally. The old RW_DATA_SECTION had INIT_TASK_DATA (which was more-than-PAGE_SIZE-aligned), followed by a bunch of small alignment stuff, followed by more PAGE_SIZE-aligned stuff, so you wasted memory in the middle of .data re-aligning back up to PAGE_SIZE. -Tim Abbott > On Tue, 22 Sep 2009, Tim Abbott wrote: > > > > Signed-off-by: Tim Abbott > > Reviewed-by: Sam Ravnborg > > --- > > include/asm-generic/vmlinux.lds.h | 4 ++-- > > 1 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > > index 29ca8f5..b6e818f 100644 > > --- a/include/asm-generic/vmlinux.lds.h > > +++ b/include/asm-generic/vmlinux.lds.h > > @@ -721,12 +721,12 @@ > > . = ALIGN(PAGE_SIZE); \ > > .data : AT(ADDR(.data) - LOAD_OFFSET) { \ > > INIT_TASK_DATA(inittask) \ > > + NOSAVE_DATA \ > > + PAGE_ALIGNED_DATA(pagealigned) \ > > CACHELINE_ALIGNED_DATA(cacheline) \ > > READ_MOSTLY_DATA(cacheline) \ > > DATA_DATA \ > > CONSTRUCTORS \ > > - NOSAVE_DATA \ > > - PAGE_ALIGNED_DATA(pagealigned) \ > > } > > > > #define INIT_TEXT_SECTION(inittext_align) \ > > -- > > 1.6.3.3 > > > -- 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/