From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <445C5F36.3030207@yahoo.com.au> Date: Sat, 06 May 2006 18:32:54 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: assert/crash in __rmqueue() when enabling CONFIG_NUMA References: <44576688.6050607@mbligh.org> <44576BF5.8070903@yahoo.com.au> <20060504013239.GG19859@localhost> <1146756066.22503.17.camel@localhost.localdomain> <20060504154652.GA4530@localhost> <20060504192528.GA26759@elte.hu> <20060504194334.GH19859@localhost> <445A7725.8030401@shadowen.org> <20060505135503.GA5708@localhost> <1146839590.22503.48.camel@localhost.localdomain> <20060505145018.GI19859@localhost> <1146841064.22503.53.camel@localhost.localdomain> In-Reply-To: <1146841064.22503.53.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Bob Picco , Andy Whitcroft , Ingo Molnar , "Martin J. Bligh" , Andi Kleen , linux-kernel@vger.kernel.org, Andrew Morton , Linux Memory Management List-ID: Dave Hansen wrote: > Ahhh. I hadn't made the ia64 connection. I wonder if it is worth > making CONFIG_HOLES_IN_ZONE say ia64 or something about vmem_map in it > somewhere. Might be worth at least a comment like this: > > + if (page_in_zone_hole(buddy)) /* noop on all but ia64 */ > + break; > + else if (page_zonenum(buddy) != page_zonenum(page)) > + break; > + else if (!page_is_buddy(buddy, order)) > break; /* Move the buddy up one level. */ > > BTW, wasn't the whole idea of discontig to have holes in zones (before > NUMA) without tricks like this? ;) Yes. I don't like the patch much, because all that logic should be moved into page_is_buddy where I put it (surely it is more readable not to have the checks spilling out -- a page which is not in the correct zone or is a "hole" is by definition not a buddy, right?) So, I agree with adding the zone check if any architecture needs it. But it would be something under CONFIG_HOLES_IN_ZONE, and the arch needs to *either* align zones correctly (as they've always had to), or turn this option on. Thanks for working at this, everyone. -- SUSE Labs, Novell Inc. 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