diff options
| author | Dennis Zhou (Facebook) <dennisszhou@gmail.com> | 2017-07-24 19:02:13 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2017-07-26 17:41:05 -0400 |
| commit | 86b442fbce74d6cd0805410ef228776cbd0338d7 (patch) | |
| tree | 1d1fb3282d54d73cc47c0ba7f8a09a9050db23ae | |
| parent | ca460b3c96274d79f84b31a3fea23a6eed479917 (diff) | |
percpu: add first_bit to keep track of the first free in the bitmap
This patch adds first_bit to keep track of the first free bit in the
bitmap. This hint helps prevent scanning of fully allocated blocks.
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | mm/percpu-internal.h | 2 | ||||
| -rw-r--r-- | mm/percpu-stats.c | 1 | ||||
| -rw-r--r-- | mm/percpu.c | 17 |
3 files changed, 17 insertions, 3 deletions
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h index 252ae9e960e0..e60e04966d96 100644 --- a/mm/percpu-internal.h +++ b/mm/percpu-internal.h @@ -36,7 +36,7 @@ struct pcpu_chunk { struct pcpu_block_md *md_blocks; /* metadata blocks */ void *data; /* chunk data */ - int first_free; /* no free below this */ + int first_bit; /* no free below this */ bool immutable; /* no [de]population allowed */ int start_offset; /* the overlap with the previous region to have a page aligned diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c index ad03d73aa5fe..6142484e88f7 100644 --- a/mm/percpu-stats.c +++ b/mm/percpu-stats.c @@ -121,6 +121,7 @@ static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk, P("nr_alloc", chunk->nr_alloc); P("max_alloc_size", chunk->max_alloc_size); P("empty_pop_pages", chunk->nr_empty_pop_pages); + P("first_bit", chunk->first_bit); P("free_bytes", chunk->free_bytes); P("contig_bytes", chunk->contig_bits * PCPU_MIN_ALLOC_SIZE); P("sum_frag", sum_frag); diff --git a/mm/percpu.c b/mm/percpu.c index 708c6de237b9..83abb190ca5a 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -427,7 +427,7 @@ static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk) chunk->contig_bits = 0; bits = nr_empty_pop_pages = 0; - pcpu_for_each_unpop_region(chunk->alloc_map, rs, re, 0, + pcpu_for_each_unpop_region(chunk->alloc_map, rs, re, chunk->first_bit, pcpu_chunk_map_bits(chunk)) { bits = re - rs; @@ -646,7 +646,8 @@ static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, int bit_off, bits; int re; /* region end */ - pcpu_for_each_unpop_region(chunk->alloc_map, bit_off, re, 0, + pcpu_for_each_unpop_region(chunk->alloc_map, bit_off, re, + chunk->first_bit, pcpu_chunk_map_bits(chunk)) { bits = re - bit_off; @@ -715,6 +716,13 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, chunk->free_bytes -= alloc_bits * PCPU_MIN_ALLOC_SIZE; + /* update first free bit */ + if (bit_off == chunk->first_bit) + chunk->first_bit = find_next_zero_bit( + chunk->alloc_map, + pcpu_chunk_map_bits(chunk), + bit_off + alloc_bits); + pcpu_block_update_hint_alloc(chunk, bit_off, alloc_bits); pcpu_chunk_relocate(chunk, oslot); @@ -750,6 +758,9 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int off) /* update metadata */ chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE; + /* update first free bit */ + chunk->first_bit = min(chunk->first_bit, bit_off); + pcpu_block_update_hint_free(chunk, bit_off, bits); pcpu_chunk_relocate(chunk, oslot); @@ -841,6 +852,8 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, set_bit(0, chunk->bound_map); set_bit(offset_bits, chunk->bound_map); + chunk->first_bit = offset_bits; + pcpu_block_update_hint_alloc(chunk, 0, offset_bits); } |