diff options
| author | Kent Overstreet <kmo@daterainc.com> | 2013-11-11 21:58:34 (GMT) |
|---|---|---|
| committer | Kent Overstreet <kmo@daterainc.com> | 2013-12-16 22:22:59 (GMT) |
| commit | 16749c23c00c686ed168471963e3ddb0f3fcd855 (patch) | |
| tree | c64fc28761ab499bbcdcf1f626576d1781c87ba9 /drivers/md/bcache/util.c | |
| parent | 6d3d1a9c542b19dff1c7d7c8354d0869e4655287 (diff) | |
| download | linux-16749c23c00c686ed168471963e3ddb0f3fcd855.tar.xz | |
bcache: New writeback PD controller
The old writeback PD controller could get into states where it had throttled all
the way down and take way too long to recover - it was too complicated to really
understand what it was doing.
This rewrites a good chunk of it to hopefully be simpler and make more sense,
and it also pays more attention to units which should make the behaviour a bit
easier to understand.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Diffstat (limited to 'drivers/md/bcache/util.c')
| -rw-r--r-- | drivers/md/bcache/util.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c index 462214e..bb37618 100644 --- a/drivers/md/bcache/util.c +++ b/drivers/md/bcache/util.c @@ -209,7 +209,13 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done) { uint64_t now = local_clock(); - d->next += div_u64(done, d->rate); + 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; + + if (time_after64(now - NSEC_PER_SEC * 2, d->next)) + d->next = now - NSEC_PER_SEC * 2; return time_after64(d->next, now) ? div_u64(d->next - now, NSEC_PER_SEC / HZ) |