Messages in this thread | | | Date | Wed, 13 Aug 2008 20:35:34 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [RFC PATCH] x86 alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug |
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Mathieu Desnoyers wrote: > A virtualized guest kernel could use that to limit its use of the > overall machine CPU resources in different time periods. Policies can > determine how many physical CPU a virtual machine can be tied to, and > that may change depending on e.g. the workload or time of day. Having > the ability to efficiently switch to UP for a long period of time seems > important in this use-case.
Not very convinced. Unplugging cpus is a pretty coarse way to control resource use. There are lots of other mechanisms. And it's not like an uncontended lock is all that expensive these days...
J
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