Re: [RFC] Userspace RCU: (ab)using futexes to save cpu cycles and energy

Michael Schnell
2009-09-28T07:24:01Z

Mathieu Desnoyers wrote:
>
> The mutex code (and usual futex users) use futex to implement mutual
> exclusion. My goal is to send a wakeup signal to a thread waiting for
> work to perform when adding such work. But without any mutual exclusion.

Why is that different ?

if you use a normal FUTEX like pthread_mutex_...() and have the thread
block right at the start (by blocking the *UTEX before creating the
thread). Now you can wake the thread by unblocking the *UTEX.

-Michael