US Patent No. 10,599,468

HOUSEKEEPING VIRTUAL PROCESSOR OVERCOMMIT FOR REAL TIME VIRTUALIZATION


Patent No. 10,599,468
Issue Date March 24, 2020
Title Housekeeping Virtual Processor Overcommit For Real Time Virtualization
Inventorship Henri van Riel, Westford, MA (US)
Luiz Capitulino, Quebec (CA)
Marcelo Tosatti, San Paulo (BR)
Assignee Red Hat, Inc., Raleigh, NC (US)

Claim of US Patent No. 10,599,468

1. A system comprising:a hypervisor;
one or more virtual machines; and
one or more virtual processors, associated with on one or more physical processors, including a real time virtual processor adapted to perform real time data processing and a housekeeping virtual processor adapted to perform non-real time data processing for housekeeping tasks, wherein the housekeeping virtual processor is configured to:
initiate a non-preemptible, non-real time housekeeping task that includes acquiring a lock,
responsive to initiating the non-preemptible, non-real time housekeeping task, increment a counter value from an initial counter value, wherein a respective counter value greater than the initial counter value indicates that the housekeeping virtual processor is in a respective critical section of a plurality of respective critical sections,
complete the non-preemptible, non-real time housekeeping task, wherein completing the non-preemptible, non-real time housekeeping task includes releasing the lock,
responsive to completing the non-preemptible, non-real time housekeeping task, decrement the counter value towards the initial counter value,
responsive to the counter value reaching the initial counter value, check a flag and determine a status of the flag as one of (i) set by the hypervisor to yield on unlock and (ii) unset, and
responsive to checking the flag and determining the status as set by the hypervisor to yield on unlock, execute a hypercall to yield a processor of the one or more physical processors associated with the housekeeping virtual processor after the housekeeping virtual processor has completed each of the respective critical sections.