Messages in this thread |  | | Date | Tue, 21 Oct 2014 10:58:10 -0400 | From | Steven Rostedt <> | Subject | Re: lockdep splat in CPU hotplug |
| |
On Tue, Oct 21, 2014 at 01:09:04PM +0200, Jiri Kosina wrote: > Hi, > > I am seeing the lockdep report below when resuming from suspend-to-disk > with current Linus' tree (c2661b80609). > > The reason for CCing Ingo and Peter is that I can't make any sense of one > of the stacktraces lockdep is providing. > > Please have a look at the very first stacktrace in the dump, where lockdep > is trying to explain where cpu_hotplug.lock#2 has been acquired. It seems > to imply that cpuidle_pause() is taking cpu_hotplug.lock, but that's not > the case at all. > > What am I missing? >
> > -> #1 (cpu_hotplug.lock#2){+.+.+.}: > [<ffffffff81099fac>] lock_acquire+0xac/0x130 > [<ffffffff815b9f2c>] mutex_lock_nested+0x5c/0x3b0 > [<ffffffff81491892>] cpuidle_pause+0x12/0x30 > [<ffffffff81402314>] dpm_suspend_noirq+0x44/0x340 > [<ffffffff81402958>] dpm_suspend_end+0x38/0x80 > [<ffffffff810a07bd>] hibernation_snapshot+0xcd/0x370 > [<ffffffff810a1248>] hibernate+0x168/0x210 > [<ffffffff8109e9b4>] state_store+0xe4/0xf0 > [<ffffffff813003ef>] kobj_attr_store+0xf/0x20 > [<ffffffff8121e9a3>] sysfs_kf_write+0x43/0x60 > [<ffffffff8121e287>] kernfs_fop_write+0xe7/0x170 > [<ffffffff811a7342>] vfs_write+0xb2/0x1f0 > [<ffffffff811a7da4>] SyS_write+0x44/0xb0 > [<ffffffff815be856>] system_call_fastpath+0x16/0x1b
Yeah, this backtrace looks totally bogus. Unless there's some magic going on with grabbing the get_online_cpus here?
Could you send your config. Maybe it has to do with some debug magic?
-- Steve
|  |