From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 411CA6B004D for ; Sat, 29 Aug 2009 07:01:08 -0400 (EDT) Date: Sat, 29 Aug 2009 13:00:46 +0200 From: Ingo Molnar Subject: Re: [PATCH] x86: reuse the boot-time mappings of fixed_addresses Message-ID: <20090829110046.GA6812@elte.hu> References: <4A90AADE.20307@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A90AADE.20307@gmail.com> Sender: owner-linux-mm@kvack.org To: Xiao Guangrong Cc: Andrew Morton , "H. Peter Anvin" , Rusty Russell , Jens Axboe , Xiao Guangrong , LKML , linux-mm@kvack.org, x86@kernel.org, Jeremy Fitzhardinge , Thomas Gleixner List-ID: * Xiao Guangrong wrote: > From: Xiao Guangrong > > Some fixed_addresses items are only used when system boot, after > boot, they are free but no way to use, like early ioremap area. > They are wasted for us, we can reuse them after system boot. > > In this patch, we put them in permanent kmap's area and expand > vmalloc's address range. In boot time, reserve them in > permanent_kmaps_init() to avoid multiple used, after system boot, > we unreserved them then user can use it. > > Signed-off-by: Xiao Guangrong > --- > arch/x86/include/asm/fixmap.h | 2 ++ > arch/x86/include/asm/pgtable_32_types.h | 4 ++-- > arch/x86/mm/init_32.c | 8 ++++++++ > include/linux/highmem.h | 2 ++ > mm/highmem.c | 26 ++++++++++++++++++++++++++ > 5 files changed, 40 insertions(+), 2 deletions(-) I'm wondering, how much space do we save this way, on a typical bootup on a typical PC? Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org