Re: [RFC PATCH 00/17] virtual-bus

From: Avi Kivity
Date: Thu Apr 02 2009 - 11:59:12 EST


Herbert Xu wrote:
On Thu, Apr 02, 2009 at 06:00:17PM +0300, Avi Kivity wrote:
Good point - if we rely on having excess cores in the host, large guest scalability will drop.

Going back to TX mitigation, I wonder if we could avoid it altogether
by having a "wakeup" mechanism that does not involve a vmexit. We
have two cases:

1) UP, or rather guest runs on the same core/hyperthread as the
backend. This is the easy one, the guest simply sets a marker
in shared memory and keeps going until its time is up. Then the
backend takes over, and uses a marker for notification too.

The markers need to be interpreted by the scheduler so that it
knows the guest/backend is runnable, respectively.

Let's look at this first.

What if the guest sends N packets, then does some expensive computation (say the guest scheduler switches from the benchmark process to evolution). So now we have the marker set at packet N, but the host will not see it until the guest timeslice is up?

I think I totally misunderstood you. Can you repeat in smaller words?

--
error compiling committee.c: too many arguments to function

--
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/