diff options
| -rw-r--r-- | mm/percpu.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 769b7583975b..cbace9e79f2d 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -546,6 +546,21 @@ static inline int pcpu_cnt_pop_pages(struct pcpu_chunk *chunk, int bit_off, bitmap_weight(chunk->populated, page_start); } +/* + * pcpu_region_overlap - determines if two regions overlap + * @a: start of first region, inclusive + * @b: end of first region, exclusive + * @x: start of second region, inclusive + * @y: end of second region, exclusive + * + * This is used to determine if the hint region [a, b) overlaps with the + * allocated region [x, y). + */ +static inline bool pcpu_region_overlap(int a, int b, int x, int y) +{ + return (a < y) && (x < b); +} + /** * pcpu_chunk_update - updates the chunk metadata given a free area * @chunk: chunk of interest @@ -710,8 +725,11 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, PCPU_BITMAP_BLOCK_BITS, s_off + bits); - if (s_off >= s_block->contig_hint_start && - s_off < s_block->contig_hint_start + s_block->contig_hint) { + if (pcpu_region_overlap(s_block->contig_hint_start, + s_block->contig_hint_start + + s_block->contig_hint, + s_off, + s_off + bits)) { /* block contig hint is broken - scan to fix it */ pcpu_block_refresh_hint(chunk, s_index); } else { @@ -764,8 +782,10 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, * contig hint is broken. Otherwise, it means a smaller space * was used and therefore the chunk contig hint is still correct. */ - if (bit_off >= chunk->contig_bits_start && - bit_off < chunk->contig_bits_start + chunk->contig_bits) + if (pcpu_region_overlap(chunk->contig_bits_start, + chunk->contig_bits_start + chunk->contig_bits, + bit_off, + bit_off + bits)) pcpu_chunk_refresh_hint(chunk); } |