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:
Aug. 27, 2019
Filed:
Feb. 16, 2018
Microsoft Technology Licensing, Llc, Redmond, WA (US);
Omar Carey, Redmond, WA (US);
Rajsekhar Das, Sammamish, WA (US);
Microsoft Technology Licensing, LLC, Redmond, WA (US);
Abstract
A cluster allocation bitmap determines which clusters in a band of storage remain unallocated. However, concurrent access to a cluster allocation bitmap can cause CPU stalls as copies of the cluster allocation bitmap in a CPU's level 1 (L1) cache are invalidated by another CPU allocating from the same bitmap. In one embodiment, cluster allocation bitmaps are divided into L1 cache line sized and aligned chunks. Each core of a multicore CPU is directed at random to allocate space out of a chunk. Because the chunks are L1 cache line aligned, the odds of the same portion of the cluster allocation bitmap being loaded into multiple L1 caches by multiple CPU cores is reduced, reducing the odds of an L1 cache invalidation. The number of CPU cores performing allocations on a given cluster allocation bitmap is limited based on the number of chunks with unallocated space that remain.