Re: [PATCH] Fix lockup on panic with lockdep

2014-05-14 Thread Jan Kara
On Tue 13-05-14 13:29:58, Andrew Morton wrote: > On Mon, 12 May 2014 17:41:54 -0700 Derek Basehore > wrote: > > > If we don't call mutex_acquire at the beginning of console_unblank, we can > > run > > into a lockup on the logbuf_lock between console_unlock and printk during > > panic. > > What

Re: [PATCH] Fix lockup on panic with lockdep

2014-05-13 Thread Andrew Morton
On Mon, 12 May 2014 17:41:54 -0700 Derek Basehore wrote: > If we don't call mutex_acquire at the beginning of console_unblank, we can run > into a lockup on the logbuf_lock between console_unlock and printk during > panic. > What happens in console_unlock is: > > -locks logbuf_lock > -calls mu

[PATCH] Fix lockup on panic with lockdep

2014-05-12 Thread Derek Basehore
If we don't call mutex_acquire at the beginning of console_unblank, we can run into a lockup on the logbuf_lock between console_unlock and printk during panic. What happens in console_unlock is: -locks logbuf_lock -calls mutex_release -which calls printk -which locks logbuf_lock This fixes the