On 10/16/2019 12:12 AM, Qian Cai wrote: > On Tue, 2019-10-15 at 20:51 +0530, Anshuman Khandual wrote: >> >> On 10/15/2019 08:11 PM, Qian Cai wrote: >>> 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/0x490 >> >> Hmm, 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 ? > > Yes, this patch works fine. > > diff --git a/init/main.c b/init/main.c > index 676d8020dd29..591be8f9e8e0 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -1177,7 +1177,6 @@ static noinline void __init kernel_init_freeable(void) > workqueue_init(); > > init_mm_internals(); > - debug_vm_pgtable(); > > do_pre_smp_initcalls(); > lockup_detector_init(); > @@ -1186,6 +1185,8 @@ static noinline void __init kernel_init_freeable(void) > sched_init_smp(); > > page_alloc_init_late(); > + debug_vm_pgtable(); > + > /* Initialize page ext after all struct pages are initialized. */ > page_ext_init(); > Sure, will keep this in mind if we at all end up with memory allocation approach for this test. >> >> [ 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+ # >
