diff options
Diffstat (limited to 'drivers/md/bcache/request.c')
| -rw-r--r-- | drivers/md/bcache/request.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index f11123079fe0..41adcd1546f1 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -329,12 +329,13 @@ void bch_data_insert(struct closure *cl) bch_data_insert_start(cl); } -/* Congested? */ - -unsigned int bch_get_congested(struct cache_set *c) +/* + * Congested? Return 0 (not congested) or the limit (in sectors) + * beyond which we should bypass the cache due to congestion. + */ +unsigned int bch_get_congested(const struct cache_set *c) { int i; - long rand; if (!c->congested_read_threshold_us && !c->congested_write_threshold_us) @@ -353,8 +354,7 @@ unsigned int bch_get_congested(struct cache_set *c) if (i > 0) i = fract_exp_two(i, 6); - rand = get_random_int(); - i -= bitmap_weight(&rand, BITS_PER_LONG); + i -= hweight32(get_random_u32()); return i > 0 ? i : 1; } @@ -376,7 +376,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) { struct cache_set *c = dc->disk.c; unsigned int mode = cache_mode(dc); - unsigned int sectors, congested = bch_get_congested(c); + unsigned int sectors, congested; struct task_struct *task = current; struct io *i; @@ -412,6 +412,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) goto rescale; } + congested = bch_get_congested(c); if (!congested && !dc->sequential_cutoff) goto rescale; |