Eli Criffield wrote:
On a guests (or domU or whatever) that are sharing a single CPU what bucket to jiffies go into when a guest waits for its turn on the CPU?.
In paravirtualized situations, eg. Xen, s390, zSeries and IBM PPC64, the time in which a virtual cpu (1) had a task to run but (2) was not actually running, is counted as steal time.
So if a guest wants a 100% of the cpu, but only gets 50% because another guests (of the same priority) running on the same cpu wants 100% too, where does it put the jiffies that have passed while it wanted to do something but didn't have the cpu?
Since 2.6.11, steal time. Before 2.6.11, some unlucky task would get billed for the time. In a fully virtualized environment, where the guest OS has no idea that it is running in a virtual machine, some unlucky task will get billed for the time used by another virtual machine. There are some other advantages to paravirtualization: http://virt.kernelnewbies.org/ParavirtBenefits -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
