From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760717AbYBOXR4 (ORCPT ); Fri, 15 Feb 2008 18:17:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752238AbYBOXRt (ORCPT ); Fri, 15 Feb 2008 18:17:49 -0500 Received: from waste.org ([66.93.16.53]:60438 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169AbYBOXRs (ORCPT ); Fri, 15 Feb 2008 18:17:48 -0500 Subject: Re: arch/x86/mm/ioremap unification grew by 10x From: Matt Mackall To: Sam Ravnborg Cc: Linux Mailing List , Ingo Molnar , Ian Campbell In-Reply-To: <1203110488.12383.231.camel@cinder.waste.org> References: <1203107155.12383.230.camel@cinder.waste.org> <20080215203228.GA4295@uranus.ravnborg.org> <1203110488.12383.231.camel@cinder.waste.org> Content-Type: text/plain Date: Fri, 15 Feb 2008 17:17:05 -0600 Message-Id: <1203117425.12383.238.camel@cinder.waste.org> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-02-15 at 15:21 -0600, Matt Mackall wrote: > On Fri, 2008-02-15 at 21:32 +0100, Sam Ravnborg wrote: > > On Fri, Feb 15, 2008 at 02:25:54PM -0600, Matt Mackall wrote: > > > In 2.6.24 defconfig, my build stats show ioremap_32.o was 1.8k. In > > > 2.6.25-rc1, the unified ioremap.o is 20.8k. > > > > Just an observation - 17 commits touches said file after > > the unification (at least in latest -linus). > > Correction: those numbers should be halved. So we're going from .9k to > 10.4k. And here's most of the cause: 000002b8 00000124 T early_ioremap 00001000 00001000 t bm_pte 00002000 00000004 T early_ioremap_debug static __initdata pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __attribute__((aligned(PAGE_SIZE))); Double ouch. First, this isn't in BSS. Second, even though it's initdata, the alignment slop won't get recovered. Don't we have a special section for page-aligned crap so it doesn't waste most of two pages? -- Mathematics is the supreme nostalgia of our time.