diff options
Diffstat (limited to 'drivers/md/bcache/util.c')
| -rw-r--r-- | drivers/md/bcache/util.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c index 176d3c2ef5f5c..e548b8b513227 100644 --- a/drivers/md/bcache/util.c +++ b/drivers/md/bcache/util.c @@ -232,8 +232,14 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done) d->next += div_u64(done * NSEC_PER_SEC, d->rate); - if (time_before64(now + NSEC_PER_SEC, d->next)) - d->next = now + NSEC_PER_SEC; + /* Bound the time. Don't let us fall further than 2 seconds behind + * (this prevents unnecessary backlog that would make it impossible + * to catch up). If we're ahead of the desired writeback rate, + * don't let us sleep more than 2.5 seconds (so we can notice/respond + * if the control system tells us to speed up!). + */ + if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next)) + d->next = now + NSEC_PER_SEC * 5LLU / 2LLU; if (time_after64(now - NSEC_PER_SEC * 2, d->next)) d->next = now - NSEC_PER_SEC * 2; |