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| author | Omar Sandoval <osandov@fb.com> | 2016-09-17 12:20:54 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-09-17 13:39:06 -0600 |
| commit | 5c64a8df0ca88c79c9cb74674c2481e5f7ede511 (patch) | |
| tree | a10aa8ab518921ee8f16511076a15ff2b64e52ec | |
| parent | 05fd095d53b979878f016c3a7080d3683cc89d72 (diff) | |
| download | linux-5c64a8df0ca88c79c9cb74674c2481e5f7ede511.tar.gz linux-5c64a8df0ca88c79c9cb74674c2481e5f7ede511.tar.bz2 linux-5c64a8df0ca88c79c9cb74674c2481e5f7ede511.zip | |
sbitmap: don't update the allocation hint on clear after resize
If we have a bunch of high-numbered bits allocated and then we resize
the struct sbitmap_queue, when those bits get cleared, we'll update the
hint and then have to re-randomize it repeatedly. Avoid that by checking
that the cleared bit is still a valid hint. No measurable performance
difference in the common case.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | lib/sbitmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index f736c52a712c..e40808921544 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -321,7 +321,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, { sbitmap_clear_bit(&sbq->sb, nr); sbq_wake_up(sbq); - if (likely(!sbq->round_robin)) + if (likely(!sbq->round_robin && nr < sbq->sb.depth)) *per_cpu_ptr(sbq->alloc_hint, cpu) = nr; } EXPORT_SYMBOL_GPL(sbitmap_queue_clear); |