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authorJens Axboe <axboe@kernel.dk>2021-10-08 05:44:23 -0600
committerJens Axboe <axboe@kernel.dk>2021-10-18 14:40:42 -0600
commit1aec5e4a2962f7e0b3fb3e7308dd726be2472c26 (patch)
tree8a64f12d112fa47f632b9edfc73c873a6b001e47 /lib
parent5a72e899ceb465d731c413d57c6c12cdbf88303c (diff)
sbitmap: add helper to clear a batch of tags
sbitmap currently only supports clearing tags one-by-one, add a helper that allows the caller to pass in an array of tags to clear. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'lib')
-rw-r--r--lib/sbitmap.c44
1 files changed, 41 insertions, 3 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index f398e0ae548e..c6e2f1f2c4d2 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -628,6 +628,46 @@ void sbitmap_queue_wake_up(struct sbitmap_queue *sbq)
}
EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up);
+static inline void sbitmap_update_cpu_hint(struct sbitmap *sb, int cpu, int tag)
+{
+ if (likely(!sb->round_robin && tag < sb->depth))
+ *per_cpu_ptr(sb->alloc_hint, cpu) = tag;
+}
+
+void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset,
+ int *tags, int nr_tags)
+{
+ struct sbitmap *sb = &sbq->sb;
+ unsigned long *addr = NULL;
+ unsigned long mask = 0;
+ int i;
+
+ smp_mb__before_atomic();
+ for (i = 0; i < nr_tags; i++) {
+ const int tag = tags[i] - offset;
+ unsigned long *this_addr;
+
+ /* since we're clearing a batch, skip the deferred map */
+ this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word;
+ if (!addr) {
+ addr = this_addr;
+ } else if (addr != this_addr) {
+ atomic_long_andnot(mask, (atomic_long_t *) addr);
+ mask = 0;
+ addr = this_addr;
+ }
+ mask |= (1UL << SB_NR_TO_BIT(sb, tag));
+ }
+
+ if (mask)
+ atomic_long_andnot(mask, (atomic_long_t *) addr);
+
+ smp_mb__after_atomic();
+ sbitmap_queue_wake_up(sbq);
+ sbitmap_update_cpu_hint(&sbq->sb, raw_smp_processor_id(),
+ tags[nr_tags - 1] - offset);
+}
+
void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
unsigned int cpu)
{
@@ -652,9 +692,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
*/
smp_mb__after_atomic();
sbitmap_queue_wake_up(sbq);
-
- if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth))
- *per_cpu_ptr(sbq->sb.alloc_hint, cpu) = nr;
+ sbitmap_update_cpu_hint(&sbq->sb, cpu, nr);
}
EXPORT_SYMBOL_GPL(sbitmap_queue_clear);