PATENT CLAIM ANALYSIS

Application Number: 15898407
Application Type: Utility
Filing Date: 2018-02
Publication Date: 2019-08
Patent Classification: ["711", "117000"]

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.

Claim (Index 15):
A method for storage allocation on a computing device comprising a multi-core central processing unit (CPU), each CPU core having a non-shared cache, the method comprising:\n receiving, at a filesystem allocator, a request to allocate an amount of storage on a file system volume that is divided into bands, wherein each band is composed of a plurality of storage clusters, and wherein, for each band, storage clusters are marked as allocated or unallocated by a corresponding cluster allocation bitmap; dividing a cluster allocation bitmap into a plurality of chunks, wherein each chunk is the size of a cache line of the non-shared cache, and wherein each chunk is aligned in system memory with the non-shared cache lines of the non-shared cache; determining an address within the cluster allocation bitmap based on an address of a selected chunk of the plurality of chunks; searching, beginning at the determined address, the cluster allocation bitmap for unallocated space; and allocating the unallocated space when the amount of unallocated space is identified.

Metadata:
- Claim Count in Document: 5.0
- Percentile: 88.0
- Lexical Diversity: 1.89412
- Patent Class: 711.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: False
- Related Applications: ['15898414', '15626101', '15607003', '11267938', '14943896']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.527549804239909
- 35 USC 102 Novelty (BERT): 0.5595770238226323
- Combined Prediction Score: 0.5307525261981814
- Mean Citation Score: 260.687412
- Max Citation Score: 461.45895
- Similarity Product: 355.94081711118224

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test