From 1aec5e4a2962f7e0b3fb3e7308dd726be2472c26 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 8 Oct 2021 05:44:23 -0600 Subject: 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 --- lib/sbitmap.c | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) (limited to 'lib/sbitmap.c') 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); -- cgit v1.2.3