Messages in this thread | | | Date | Mon, 11 Aug 2008 16:49:13 +0200 | From | Gerd Hoffmann <> | Subject | Re: Use of barriers in pvclock ABI |
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Glauber Costa wrote: > On Mon, Aug 11, 2008 at 4:08 AM, Gerd Hoffmann <kraxel@redhat.com> wrote: >> Due to the TSC being involved here I don't expect cross-cpu time updates >> will ever happen. IMHO it is fine to change that. > > Okay for guest vcpu, but what about physical cpus? > > IIRC, the checks are there, and so strict, to account for the > possiblity of the vcpu to be migrated to another cpu in the middle of > the > clock reading.
This is about the check in pvclock_get_time_values() that it got a consistent snapshot. Dropping that is fine.
pvclock_clocksource_read() will still notice when being migrated to another pcpu in the middle of the clock reading.
cheers, Gerd
-- http://kraxel.fedorapeople.org/xenner/
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