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Re: [Xen-devel] how can native driver response quickly for low FIFO devi

To: "Dong, Eddie" <eddie.dong@xxxxxxxxx>
Subject: Re: [Xen-devel] how can native driver response quickly for low FIFO device
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Thu, 25 May 2006 15:48:33 +0100
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On 25 May 2006, at 15:21, Dong, Eddie wrote:

Oo, understand UART is handled by Xen, Is this because of this reason?
or for debug/console use, and how about other devices?
If a user has an PCI card with 8 UART in the box, will we have problem?
thx,eddie

Oh, now I see your point. Yes, for any serial device not handled by Xen you could have a scheduling problem. Other examples include telephony interface cards and their drivers (e.g., zaptel). Higher-rate UARTs do tend to support bigger FIFOs in hardware though. Best bet if it really matters is to dedicate a logical processor to the domain that owns the hardware.

 -- Keir


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