bcache: writeback rate shouldn't artifically clamp
The previous code artificially limited writeback rate to 1000000
blocks/second (NSEC_PER_MSEC), which is a rate that can be met on fast
hardware. The rate limiting code works fine (though with decreased
precision) up to 3 orders of magnitude faster, so use NSEC_PER_SEC.
Additionally, ensure that uint32_t is used as a type for rate throughout
the rate management so that type checking/clamp_t can work properly.
bch_next_delay should be rewritten for increased precision and better
handling of high rates and long sleep periods, but this is adequate for
now.
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reported-by: Coly Li <colyli@suse.de>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index eb83be6..d77c4829 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -361,7 +361,7 @@ struct cached_dev {
int64_t writeback_rate_proportional;
int64_t writeback_rate_integral;
int64_t writeback_rate_integral_scaled;
- int64_t writeback_rate_change;
+ int32_t writeback_rate_change;
unsigned writeback_rate_update_seconds;
unsigned writeback_rate_i_term_inverse;
