Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH] Yielding processor resources during lock contention | Date | Sun, 12 Sep 2004 13:12:17 +0200 |
| |
On Sonntag, 12. September 2004 12:43, Anton Blanchard wrote: > cpu_relax doesnt tell us why we are busy looping. In this particular > case we want to pass to the hypervisor which virtual cpu we are waiting > on so the hypervisor make better scheduling decisions.
Ah, interesting. I think s390 could do the same with the upcoming 5.1 release of z/VM. However, we decided to ask for an implementation of a futex hypercall instead, which lets us implement the linux spinlock as a hypervisor semaphore.
> Did you manage to see any improvement by yielding to the hypervisor > in cpu_relax? I'm not sure if this has been measured, maybe Martin or Eberhard knows more.
Arnd <>< [unhandled content-type:application/pgp-signature] | |