Re: [RFC] time: xtime_lock is held too long

Andi Kleen
2011-05-06T17:17:05Z

> Unless I am very mistaken, it cannot explain my original report of up to
> 24.000 instructions waiting in ktime_get()

Yes it's a different problem. Sorry for hijacking your thread.

>
> BTW, how many consecutive prefetch() a cpu can 'store/execute' before
> throwing away hints ?

It depends on the CPU. Older ones had a small number only. On the
newer ones it tends to be limited by the various queues to memory,
which are a shared resource (so it also depends on what the other
threads/cores are doing)

I normally assume as a rule of thumb < 50

-Andi

--
ak@linux.intel.com -- Speaking for myself only.