From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44691D7C.5060208@yahoo.com.au> Date: Tue, 16 May 2006 10:31:56 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH 5/6] Have ia64 use add_active_range() and free_area_init_nodes References: <20060508141030.26912.93090.sendpatchset@skynet> <20060508141211.26912.48278.sendpatchset@skynet> <20060514203158.216a966e.akpm@osdl.org> <44683A09.2060404@shadowen.org> <44685123.7040501@yahoo.com.au> <446855AF.1090100@shadowen.org> <20060515192918.c3e2e895.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20060515192918.c3e2e895.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: Andy Whitcroft , akpm@osdl.org, mel@csn.ul.ie, davej@codemonkey.org.uk, tony.luck@intel.com, linux-kernel@vger.kernel.org, bob.picco@hp.com, ak@suse.de, linux-mm@kvack.org, linuxppc-dev@ozlabs.org List-ID: KAMEZAWA Hiroyuki wrote: >On Mon, 15 May 2006 11:19:27 +0100 >Andy Whitcroft wrote: > >>> >>>Recently arrived? Over a year ago with the no-buddy-bitmap patches, >>>right? Just checking because I that's what I'm assuming broke it... >>> >>Yep, sorry I forget I was out of the game for 6 months! And yes that >>was when the requirements were altered. >> >> >When no-bitmap-buddy patches was included, > >1. bad_range() is not covered by CONFIG_VM_DEBUG. It always worked. >== >static int bad_range(struct zone *zone, struct page *page) >{ > if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages) > return 1; > if (page_to_pfn(page) < zone->zone_start_pfn) > return 1; >== >And , this code >== > buddy = __page_find_buddy(page, page_idx, order); > > if (bad_range(zone, buddy)) > break; >== > >checked whether buddy is in zone and guarantees it to have page struct. > Ah, my mistake indeed. Sorry. >But clean-up/speed-up codes vanished these checks. (I don't know when this occurs) >Sorry for misses these things. > I think if anything they should be moved into page_is_buddy, however page_to_pfn is expensive on some architectures, so it is something we want to be able to opt out of if we do the correct alignment. -- Send instant messages to your online friends http://au.messenger.yahoo.com -- 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