[Xen-devel] hvm vpt lock strangeness

["Dan Magenheimer" <dan.magenheimer@xxxxxxxxxx>]

Noticed this a few days ago while working on the hvm-guest-time
on xen-system-time patch, but forgot about it...

Throughout xen/arch/x86/hvm/vpt.c, there are uses of a spinlock
called tm_lock.  But it appears that this spinlock is declared
and used as part of a per-vcpu data structure.  So is this
somehow protecting against vcpu re-entrancy (didn't think that
could happen) or is it supposed to be locking out one vcpu
against another (and not doing the job because each vcpu has
a separate lock)?  Or am I misunderstanding something entirely?

If this should be a domain-wide lock, I'll spin a patch.
(And it might explain some of the weirder time problems?)

Thanks,
Dan

===================================
Thanks... for the memory
I really could use more / My throughput's on the floor
The balloon is flat / My swap disk's fat / I've OOM's in store
Overcommitted so much
(with apologies to the late great Bob Hope)

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel