Re: [BUG on PREEMPT_RT, 2.6.23.1-rt5] in rt-mutex code and signals

["Remy Bohmer" <linux@bohmer.net>]

Hello Steven,

> > OK, I wont be able to work on this this weekend, but I'll try to get to it
> > on Monday.  A better example to show the bug you are looking for is simply
> > create a mutex and create a thread that grabs that mutex and goes to
> > sleep. Have your driver read grab that mutex with
> > mutex_lock_interruptible. And if the signal code is broken with this, then
> > you definitely got a point that the inerruptible code is broken.

I removed the 'struct semaphore' completely from my driver, using real
mutexes now instead, replace the signalling semaphores by 'struct
completion' mechanisms and got rid of the possible race I saw with the
completions in a different way, and now the problem is completely
gone!

Posix Signals work properly now (no OOPS anymore), so the problem was
likely related to the way I used the 'struct semaphore' types, which
is thus different compared to the non-RT kernel and therefor quite
confusing.

So, thank you (and Daniel) for pointing me into the right direction.

Now lets get rid of the 'struct semaphore' completely in the kernel :-))


Kind Regards,

Remy Bohmer