Hi Sebastian, On 10/30/2015 12:26 PM, Sebastian Andrzej Siewior wrote: > This patch moves the wakeup_process() invocation so it is not done under > the perm->lock by making use of a lockless wake_q. With this change, the > waiter is woken up once the message has been assigned and it does not > need to loop on SMP if the message points to NULL. In the signal case we > still need to check the pointer under the lock to verify the state. > > This change should also avoid the introduction of preempt_disable() in > -RT which avoids a busy-loop which pools for the NULL -> !NULL > change if the waiter has a higher priority compared to the waker. with regards to functional tests: fakeroot is a heavy system V user (at least if it is configured for sysv). "make -j" under fakeroot was a useful stresstest with regards to benchmarks: I've attached one of my files. Otherwise: Nice! -- Manfred