Re: [PATCH V6 0/2] mm/debug: Add tests validating architecture page table helpers
From: Michal Hocko <mhocko@kernel.org>
Date: 2019-10-16 08:20:30
Also in:
linux-arm-kernel, linux-mips, linux-mm, linux-s390, linux-sh, lkml, sparclinux
On Tue 15-10-19 20:51:11, Anshuman Khandual wrote:
On 10/15/2019 08:11 PM, Qian Cai wrote:quoted
The x86 will crash with linux-next during boot due to this series (v5) with the config below plus CONFIG_DEBUG_VM_PGTABLE=y. I am not sure if v6 would address it. https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config [ 33.862600][ T1] page:ffffea0009000000 is uninitialized and poisoned [ 33.862608][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffff871140][ T1] ? _raw_spin_unlock_irq+0x27/0x40 [ 33.871140][ T1] ? rest_init+0x307/0x307 [ 33.871140][ T1] kernel_init+0x11/0x139 [ 33.871140][ T1] ? rest_init+0x307/0x307 [ 33.871140][ T1] ret_from_fork+0x27/0x50 [ 33.871140][ T1] Modules linked in: [ 33.871140][ T1] ---[ end trace e99d392b0f7befbd ]--- [ 33.871140][ T1] RIP: 0010:alloc_gigantic_page_order+0x3fe/0x490Hmm, with defconfig (DEBUG_VM=y and DEBUG_VM_PGTABLE=y) it does not crash but with the config above, it does. Just wondering if it is possible that these pages might not been initialized yet because DEFERRED_STRUCT_PAGE_INIT=y ?
Quite likely. You need to wait for page_alloc_init_late to finish.
[ 13.898549][ T1] page:ffffea0005000000 is uninitialized and poisoned [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff [ 13.898549][ T1] page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) [ 13.898549][ T1] ------------[ cut here ]------------ [ 13.898549][ T1] kernel BUG at ./include/linux/mm.h:1107! [ 13.898549][ T1] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 13.898549][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-next-20191015+ #
-- Michal Hocko SUSE Labs