lkml.org 
[lkml]   [2017]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [BUG] lockdep splat with cpu_hotplug_lock
On Thu, 20 Jul 2017, James Bottomley wrote:
> [redirecting to linux-scsi]
> On Thu, 2017-07-20 at 19:35 -0400, Steven Rostedt wrote:
> > My tests triggered this splat on 4.13-rc1:
> >
> > Loading iSCSI transport class v2.0-870.
> > QLogic NetXtreme II iSCSI Driver bnx2i v2.7.10.1 (Jul 16, 2014)
> > iscsi: registered transport (bnx2i)
> >
> > ============================================
> > WARNING: possible recursive locking detected
> > 4.13.0-rc1-test+ #2 Not tainted
> > --------------------------------------------
> > swapper/0/1 is trying to acquire lock:
> >  (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffffb505329e>]
> > __cpuhp_setup_state+0x28/0x59
> >
> > but task is already holding lock:
> >  (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffffb64d54e9>]
> > bnx2i_mod_init+0x134/0x209
> >
> > other info that might help us debug this:
> >  Possible unsafe locking scenario:
> >
> >        CPU0
> >        ----
> >   lock(cpu_hotplug_lock.rw_sem);
> >   lock(cpu_hotplug_lock.rw_sem);
>
> It sounds like it's an annotation issue not an actual problem.  I've
> added the correct list, so hopefully our usual enthusiasts can take a
> look.

Nope. It's a recursive locking/\ of cpuhotplug lock. I'll have a look on
monday.

Thanks,

tglx

\
 
 \ /
  Last update: 2017-07-21 11:43    [W:0.048 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site