blk-iocost: decouple vrate adjustment from surplus transfers
authorTejun Heo <tj@kernel.org>
Tue, 1 Sep 2020 18:52:46 +0000 (14:52 -0400)
committerJens Axboe <axboe@kernel.dk>
Wed, 2 Sep 2020 01:38:32 +0000 (19:38 -0600)
commit065655c862fedf4b04e1b28b83ca6f338d81cf0b
tree25d65ae45d9c31f92f646f4d6d977303321ea3c5
parent8692d2db8e01f1a5718f9b67c219b823a64b2088
blk-iocost: decouple vrate adjustment from surplus transfers

Budget donations are inaccurate and could take multiple periods to converge.
To prevent triggering vrate adjustments while surplus transfers were
catching up, vrate adjustment was suppressed if donations were increasing,
which was indicated by non-zero nr_surpluses.

This entangling won't be necessary with the scheduled rewrite of donation
mechanism which will make it precise and immediate. Let's decouple the two
in preparation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/blk-iocost.c
include/trace/events/iocost.h