On 8/23/18 9:13 AM, Pavel Tatashin wrote: > On 8/23/18 7:23 AM, Michal Hocko wrote: >> On Thu 23-08-18 07:16:34, Mikulas Patocka wrote: >>> >>> >>> On Thu, 23 Aug 2018, Michal Hocko wrote: >>> >>>> On Thu 23-08-18 07:02:37, Mikulas Patocka wrote: >>>> [...] >>>>> This crash is not from -ENOENT. It crashes because page->compound_head is >>>>> 0xffffffffffffffff (see below). >>>>> >>>>> If I enable CONFIG_DEBUG_VM, I also get VM_BUG. >>>> >>>> This smells like the struct page is not initialized properly. How is >>>> this memory range added? I mean is it brought up by the memory hotplug >>>> or during the boot? > > I believe it is due to uninitialized struct pages. Mikulas, could you > please provide config file, and also the full console output. > > Please make sure that you have: > CONFIG_DEBUG_VM=y > CONFIG_ARCH_HAS_DEBUG_VIRTUAL=y I meant: CONFIG_DEBUG_VM=y CONFIG_DEBUG_VM_PGFLAGS=y > > I wonder what kind of struct page memory layout is used, and also if > deferred struct pages are enabled or not. > > Have you tried bisecting the problem? > > Thank you, > Pavel >
