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Re: [Xen-devel] Xen spinlock questions

Keir Fraser wrote:
On 11/8/08 19:49, "Jeremy Fitzhardinge" <jeremy@xxxxxxxx> wrote:

Keir Fraser wrote:
That's right. The hypercall returns if any event is delivered to the vcpu,
or if any port in the poll set is pending. The fact we don't clear the vcpu
from the poll_mask if unblocked for event delivery isn't a correctness
issue, but it will cause unnecessary extra work in future invocations of
evtchn_set_pending(). Perhaps vcpu_unblock() should clear it.
That seems reasonable.  In this use-case, it's quite likely that if the
poll is interrupted by event delivery, on return it will find that the
spinlock is now free and never re-enter the poll.

Attached is a new version of the patch which clears the vcpu from poll_mask
when it is unblocked for any reason. Jan: please can you give this one a
spin if you get time.

Forgot to attach?


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