Like the following, mmu_notifier can be called after registering immediately. So, kvm have to initialize kvm->mmu_lock before it. BUG: spinlock bad magic on CPU#0, kswapd0/342 lock: ffff8800af8c4000, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Pid: 342, comm: kswapd0 Not tainted 2.6.39-rc5+ #1 Call Trace: [<ffffffff8118ce61>] spin_bug+0x9c/0xa3 [<ffffffff8118ce91>] do_raw_spin_lock+0x29/0x13c [<ffffffff81024923>] ? flush_tlb_others_ipi+0xaf/0xfd [<ffffffff812e22f3>] _raw_spin_lock+0x9/0xb [<ffffffffa0582325>] kvm_mmu_notifier_clear_flush_young+0x2c/0x66 [kvm] [<ffffffff810d3ff3>] __mmu_notifier_clear_flush_young+0x2b/0x57 [<ffffffff810c8761>] page_referenced_one+0x88/0xea [<ffffffff810c89bf>] page_referenced+0x1fc/0x256 [<ffffffff810b2771>] shrink_page_list+0x187/0x53a [<ffffffff810b2ed7>] shrink_inactive_list+0x1e0/0x33d [<ffffffff810acf95>] ? determine_dirtyable_memory+0x15/0x27 [<ffffffff812e90ee>] ? call_function_single_interrupt+0xe/0x20 [<ffffffff810b3356>] shrink_zone+0x322/0x3de [<ffffffff810a9587>] ? zone_watermark_ok_safe+0xe2/0xf1 [<ffffffff810b3928>] kswapd+0x516/0x818 [<ffffffff810b3412>] ? shrink_zone+0x3de/0x3de [<ffffffff81053d17>] kthread+0x7d/0x85 [<ffffffff812e9394>] kernel_thread_helper+0x4/0x10 [<ffffffff81053c9a>] ? __init_kthread_worker+0x37/0x37 [<ffffffff812e9390>] ? gs_change+0xb/0xb Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN virt/kvm/kvm_main.c~kvm-mmu_notifier-lock-fix virt/kvm/kvm_main.c --- linux-2.6/virt/kvm/kvm_main.c~kvm-mmu_notifier-lock-fix 2011-05-11 09:21:52.000000000 +0900 +++ linux-2.6-hirofumi/virt/kvm/kvm_main.c 2011-05-11 09:22:04.000000000 +0900 @@ -467,6 +467,7 @@ static struct kvm *kvm_create_vm(void) if (!kvm->buses[i]) goto out_err; } + spin_lock_init(&kvm->mmu_lock); r = kvm_init_mmu_notifier(kvm); if (r) @@ -474,7 +475,6 @@ static struct kvm *kvm_create_vm(void) kvm->mm = current->mm; atomic_inc(&kvm->mm->mm_count); - spin_lock_init(&kvm->mmu_lock); kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); _ -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
