Re: [Xen-devel] [PATCH] xen/evtchn: Handle VIRQ_TIMER before anyother hardirq in event loop.

From: David Vrabel
Date: Tue Apr 02 2013 - 10:53:21 EST


On 01/04/13 15:07, Konrad Rzeszutek Wilk wrote:
> From: Keir Fraser <keir.fraser@xxxxxxxxxx>
>
> This avoids any other hardirq handler seeing a very stale jiffies
> value immediately after wakeup from a long idle period. The one
> observable symptom of this was a USB keyboard, with software keyboard
> repeat, which would always repeat a key immediately that it was
> pressed. This is due to the key press waking the guest, the key
> handler immediately runs, sees an old jiffies value, and then that
> jiffies value significantly updated, before the key is unpressed.

It's a bit of hack but what else can you do when there is no generic
mechanism to have different event priorities.

Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx>

The subject should be prefixed with: "xen/events" as this isn't a patch
to the evtchn driver.

David
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