If a cgroup share gets shrinked but the cgroup hits its limit, the shrink isn't optimal, we restore its original share.
Signed-off-by: Shaohua Li <[email protected]> --- block/blk-throttle.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 2271c7e..7db7d8e 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2229,6 +2229,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, sq = &tg->service_queue; +again: tg_check_new_weight(tg); detect_inactive_cg(tg); while (true) { @@ -2238,8 +2239,18 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, tg_update_perf(tg); /* if above limits, break to queue */ - if (!tg_may_dispatch(tg, bio, NULL)) + if (!tg_may_dispatch(tg, bio, NULL)) { + /* + * If the cg hits limit but its share is shrinked, the + * shrink isn't optimal + */ + if (sq->acting_weight < sq->weight) { + /* pretend we are changing weight */ + sq->new_weight = sq->weight; + goto again; + } break; + } /* within limits, let's charge and dispatch directly */ throtl_charge_bio(tg, bio); -- 2.6.5
