The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 2020
Filed:
Oct. 01, 2018
Prevent counter wrap during update-side grace-period-request processing in tree-srcu implementations
International Business Machines Corporation, Armonk, NY (US);
Paul E. McKenney, Beaverton, OR (US);
INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US);
Abstract
In an SRCU environment, per-processor data structures each maintain a list of SRCU callbacks enqueued by SRCU updaters. An SRCU management data structure maintains a current-grace-period counter that tracks a current SRCU grace period, and a future-grace-period counter that tracks a farthest-in-the-future SRCU grace period needed by the SRCU callbacks enqueued by the SRCU updaters. A combining tree is used to mediate a plurality of grace-period-start requests concurrently vying for an opportunity to update the future-grace-period record on behalf of SRCU callbacks. The current-grace-period counter is prevented from wrapping during some or all of the grace-period-start request processing. In an embodiment, the counter wrapping is prevented by performing some or all of the grace-period start-request processing within an SRCU read-side critical section.