Re: [RFC PATCH 0/4] Gang scheduling in CFS

From: Nikunj A Dadhania
Date: Mon Dec 19 2011 - 07:05:43 EST


On Mon, 19 Dec 2011 13:59:37 +0200, Avi Kivity <avi@xxxxxxxxxx> wrote:
> On 12/19/2011 01:50 PM, Nikunj A Dadhania wrote:
> > On Mon, 19 Dec 2011 13:44:02 +0200, Avi Kivity <avi@xxxxxxxxxx> wrote:
> > > On 12/19/2011 01:23 PM, Ingo Molnar wrote:
> > > > What's behind this huge speedup? Does ebizzy use user-space
> > > > spinlocks perhaps? Could we do something on the user-space side
> > > > to get a similar speedup?
> > >
> > > kvm tries to detect spinlocks (by trapping repeated executions of PAUSE)
> > > and yield to a related vcpu. It's far from perfect however, and relies
> > > on the spinlock code using PAUSE.
> > >
> > Avi, is this soft-PLE kind of thing?
>
> No, hard PLE, see the calls to yield_to.
>
The above ebizzy result is from a non-PLE machine, will yield_to come
in to picture here?

I have two set of results, one for PLE machine and other for non-PLE.

Nikunj

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/