From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 18 Mar 2008 10:45:51 -0700 (PDT) From: Christoph Lameter Subject: Re: [BUG] in 2.6.25-rc3 with 64k page size and SLUB_DEBUG_ON In-Reply-To: <200803181744.58735.Jens.Osterkamp@gmx.de> Message-ID: References: <200803061447.05797.Jens.Osterkamp@gmx.de> <200803121619.45708.Jens.Osterkamp@gmx.de> <200803181744.58735.Jens.Osterkamp@gmx.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Jens Osterkamp Cc: Pekka J Enberg , linux-mm@kvack.org List-ID: On Tue, 18 Mar 2008, Jens Osterkamp wrote: > Actually the caller expects exactly that. The kmalloc that I saw was coming > from alloc_thread_info in dup_task_struct. For 4k pages this maps to > __get_free_pages whereas for 64k pages it maps to kmalloc. > The result of __get_free_pages seem to be aligned and kmalloc (with slub_debug) > of course not. That explains the 4k/64k difference and the crash I am seeing... > but I can't think of a reasonable fix right now as I don't understand the > reason for the difference in the allocation code (yet). One simple solution is to create a special slab and specify the alignment you want. The other is to use the page allocator which also gives you guaranteed alignment. -- 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