From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xensource.com>
Subject: Re: [RFC]degradation on IPF due to hypercall set irq
Date: Wed, 22 Nov 2006 10:27:47 +0000
Message-ID: <C189D6A3.4DE3%keir@xensource.com>
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To: "Xu, Anthony" <anthony.xu@intel.com>, Keir Fraser <keir@xensource.com>
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On 22/11/06 10:23, "Xu, Anthony" <anthony.xu@intel.com> wrote:

>> because it will require the shadow wire bitmap to be updated with
>> atomic accesses and the multicall state to be per-thread or to be
>> protected with a mutex. Each thread should flush multicall state
>> before it blocks.
> 
> I prefer atomic access, we used it in shared PIC.
> If each thread flush multicall seperately,
> There are some extra hypercalls.

Since the threads run independently there seems little choice but for each
to be able to flush. If the IDE DMA support had been properly integrated
into the qemu select() event loop this would not be an issue.

 -- Keir