Re: [PATCH 3/3] context_tracking,x86: remove extraneous irq disable & enable from context tracking on syscall entry

From: Ingo Molnar
Date: Fri May 01 2015 - 13:59:48 EST



* Rik van Riel <riel@xxxxxxxxxx> wrote:

> > I.e. much of what we do today, except that we could skip variable
> > work such as the scheduler tick or (unforced) RCU processing like
> > the RCU softirq work.
>
> Any ideas how we could avoid that sampling timer interrupt latency
> stacking up when dealing with both guest and host?

Well, it would be host_latency+guest_latency worst-case, right?

That should still be bounded, as long as both guest and host is
running nohz-full mode.

Also, technically when the host gets such an IRQ, the guest is
interrupted as well. So the host could do the guest's work and pass
through the result via paravirt or so.

Thanks,

Ingo
--
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/