Re: [PATCH] configure HAVE_UNSTABLE_SCHED_CLOCK for SGI_SN systems

Dimitri Sivanich
2009-01-07T13:32:30Z

Peter,

On Wed, Jan 07, 2009 at 10:53:57AM +0100, Peter Zijlstra wrote:
>
> Clock state is kept per-cpu, and locked with a spinlock. When we request

Admittedly I have not looked at this possibility too closely, but my initial concern upon looking at sched_clock_cpu() for the UNSTABLE case was the lock_double_clock() and what sort of contention that might cause on larger systems under certain conditions.