From: David Miller <davem@xxxxxxxxxxxxx> Date: Tue, 12 Aug 2008 18:40:52 -0700 (PDT) > From: Mikulas Patocka <mpatocka@xxxxxxxxxx> > Date: Tue, 12 Aug 2008 21:11:53 -0400 (EDT) > > > and then boot failure of 2.6.27-rc[12] because of bad memory > > migratetype. Is this migratetype crash a known problem? --- the problem is > > that starting with 2.6.27rc1, I'm getting crash with this backtrace: > > __list_add > > __free_pages_ok > > __free_pages > > __free_pages_bootmem > > __free_all_bootmem > > mem_init > > start_kernel_tlb_fixup_code > > --- the crash is due to migratetype == 5 in __free_one_page (inlined into > > __free_pages_ok) and because there are only 5 migratettypes, it attempts > > to add to a non-existent list. > > Mikulas can you send me the .config you're using in 2.6.27 to trigger > this? Meanwhile I tried to figure out how this can go wrong like this. The way this stuff works this early is very simple. The pageblock bitmaps get allocated by sparse_init() as it iterates over each mem section, via sparse_early_usemap_alloc(). These use the various bootmem allocators, which will zero initialize the bitmap. I added some debugging to sparse_early_usemap_alloc() to make sure the size was correct and that the pointer looked sane. What happens next is that memmap_init_zone() walks over each zone's page and initializes their pageblock migrate type to MIGRATE_MOVABLE which is "2". So given the simplicity of that stuff, I can only imagine that something is writing all over the bitmaps, clobbering them somehow. I'll try to reproduce this here so I can try to narrow down the cause a bit more, but so far my attempts have not been successful. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
