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| author | Omar Sandoval <osandov@fb.com> | 2016-09-17 01:28:23 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-09-17 08:39:10 -0600 |
| commit | 40aabb67464d5aad9ca3d2a5fedee56e2ff45aa0 (patch) | |
| tree | 19592825f8eb48363f5f9279c0d32003e7ed6532 /lib/sbitmap.c | |
| parent | 48e28166a7b608e19a6aea3acadd81cdfe660f6b (diff) | |
| download | linux-40aabb67464d5aad9ca3d2a5fedee56e2ff45aa0.tar.gz linux-40aabb67464d5aad9ca3d2a5fedee56e2ff45aa0.tar.bz2 linux-40aabb67464d5aad9ca3d2a5fedee56e2ff45aa0.zip | |
sbitmap: push per-cpu last_tag into sbitmap_queue
Allocating your own per-cpu allocation hint separately makes for an
awkward API. Instead, allocate the per-cpu hint as part of the struct
sbitmap_queue. There's no point for a struct sbitmap_queue without the
cache, but you can still use a bare struct sbitmap.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'lib/sbitmap.c')
| -rw-r--r-- | lib/sbitmap.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 4d8e97e470ee..1651ad9d5530 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -205,11 +205,18 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, if (ret) return ret; + sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); + if (!sbq->alloc_hint) { + sbitmap_free(&sbq->sb); + return -ENOMEM; + } + sbq->wake_batch = sbq_calc_wake_batch(depth); atomic_set(&sbq->wake_index, 0); sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { + free_percpu(sbq->alloc_hint); sbitmap_free(&sbq->sb); return -ENOMEM; } @@ -229,6 +236,29 @@ void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) } EXPORT_SYMBOL_GPL(sbitmap_queue_resize); +int __sbitmap_queue_get(struct sbitmap_queue *sbq, bool round_robin) +{ + unsigned int hint; + int nr; + + hint = this_cpu_read(*sbq->alloc_hint); + nr = sbitmap_get(&sbq->sb, hint, round_robin); + + if (nr == -1) { + /* If the map is full, a hint won't do us much good. */ + this_cpu_write(*sbq->alloc_hint, 0); + } else if (nr == hint || unlikely(round_robin)) { + /* Only update the hint if we used it. */ + hint = nr + 1; + if (hint >= sbq->sb.depth - 1) + hint = 0; + this_cpu_write(*sbq->alloc_hint, hint); + } + + return nr; +} +EXPORT_SYMBOL_GPL(__sbitmap_queue_get); + static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) { int i, wake_index; @@ -273,10 +303,13 @@ static void sbq_wake_up(struct sbitmap_queue *sbq) } } -void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr) +void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, + bool round_robin, unsigned int cpu) { sbitmap_clear_bit(&sbq->sb, nr); sbq_wake_up(sbq); + if (likely(!round_robin)) + *per_cpu_ptr(sbq->alloc_hint, cpu) = nr; } EXPORT_SYMBOL_GPL(sbitmap_queue_clear); |