On Mon, 2018-03-19 at 10:02 -0700, tj@kernel.org wrote:
On Mon, Mar 19, 2018 at 04:57:45PM +0000, Bart Van Assche wrote:
For synchronization primitives that wait having a stronger synchronization primitive nested inside a more relaxed one can lead to a deadlock. But since the rcu read lock primitives do not wait it could be safe to use that kind of nesting with RCU. Do you perhaps know whether any documentation is available about that kind of nesting or whether it is already used elsewhere in the kernel?
Oh, we nest them all the time. They're like (and sometimes literally are) preempt_disable() and don't care about nest ordering.
Hello Martin,
This was probably already clear to you, but anyway: please drop the patch at the start of this thread.
Thanks,
Bart.