Re: [Linux-ia64] Re: web page on O(1) scheduler

From: Jan Harkes (
Date: Wed Jun 04 2003 - 10:30:50 EST

On Wed, Jun 04, 2003 at 09:13:43AM +0200, Mike Galbraith wrote:
> Using sched_yield() as a mutex is exactly the same as using a party line
> for private conversation.

I actually used sched_yield for the 'inverse' mutex case. One thread was
pretty much exclusively holding a mutex, but other threads sometimes try
to get through the same critical section and block on mutex_lock.

The first thread then occasionally does,


Without the sched_yield, other threads never get a chance to wake up and
grab the mutex before the mutex hogging thread is back in the critical

This is ofcourse the simple explanation, this was actually part of a
wrapper around pthreads that needed to provide non-concurrent
co-routines that in specific situations could run concurrently for a bit
to do DNS lookups and such.

Not sure how different semantics affect this because I went with a
different solution a while ago.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sat Jun 07 2003 - 22:00:23 EST