[ofa-general] [Fwd: [PATCH] ib: release locks in the proper order]

[Roland Dreier]

 > Forwarding a patch written by one of our real time kernel guys.

Is there some reason why sending the patch himself is too hard?

 > RT is very sensitive to the order locks are taken and released
 > wrt read write locks. We must do
 > 
 >   lock(a);
 >   lock(b);
 >   lock(c);
 > 
 >   [...]
 > 
 >   unlock(c);
 >   unlock(b);
 >   unlock(a);
 > 
 > otherwise bad things can happen.

Maybe I'm being dense but what bad things are fixed by this patch?  I
can't even see a theoretical issue with the code as is.  This change
looks very much like fiddling for no good reason -- has a real problem
been seen with this code?

 - R.