On Tue, 2009-07-07 at 15:06 -0300, Marcelo Tosatti wrote: > KVM guests with CONFIG_LOCKDEP=y trigger the following warning: > > BUG: MAX_LOCK_DEPTH too low! > turning off the locking correctness validator. > Pid: 4624, comm: qemu-system-x86 Not tainted 2.6.31-rc2-03981-g3abaf21 > #32 > Call Trace: > [<ffffffff81068bab>] __lock_acquire+0x1559/0x15fc > [<ffffffff810be4d9>] ? mm_take_all_locks+0x99/0x109 > [<ffffffff810be4d9>] ? mm_take_all_locks+0x99/0x109 > [<ffffffff81068d3c>] lock_acquire+0xee/0x112 > [<ffffffff810be516>] ? mm_take_all_locks+0xd6/0x109 > [<ffffffff81402596>] ? _spin_lock_nest_lock+0x20/0x50 > [<ffffffff814025b7>] _spin_lock_nest_lock+0x41/0x50 > [<ffffffff810be516>] ? mm_take_all_locks+0xd6/0x109 > [<ffffffff810be516>] mm_take_all_locks+0xd6/0x109 > [<ffffffff810d0f76>] do_mmu_notifier_register+0xd4/0x199 > [<ffffffff810d1060>] mmu_notifier_register+0x13/0x15 > [<ffffffffa0107f16>] kvm_dev_ioctl+0x13f/0x30e [kvm] > [<ffffffff810e6a3a>] vfs_ioctl+0x2f/0x7d > [<ffffffff810e6fb7>] do_vfs_ioctl+0x4af/0x4ec > [<ffffffff814030b4>] ? error_exit+0x94/0xb0 > [<ffffffff81401f92>] ? trace_hardirqs_off_thunk+0x3a/0x3c > [<ffffffff8100bc2d>] ? retint_swapgs+0xe/0x13 > [<ffffffff810e703b>] sys_ioctl+0x47/0x6a > [<ffffffff811d849c>] ? __up_read+0x1a/0x85 > [<ffffffff8100b1db>] system_call_fastpath+0x16/0x1b > > Since mm_take_all_locks takes a gazillion locks. > > Is there any way around this other than completly shutting down lockdep? When we created this the promise was that kvm would only do this on a fresh mm with only a few vmas, has that changed? -- 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
