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| author | Fam Zheng <zhengfeiran@bytedance.com> | 2019-08-28 06:54:51 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-09-06 23:33:48 +0300 |
| commit | e9d3c866bf4cdbb6637e6cb268c26dfdf06d8cd3 (patch) | |
| tree | e5054d61888dcf6f15a42f89d5e0a3018601538b /block | |
| parent | a26142559c2be8c0975b941e3110d23a9e552ce5 (diff) | |
| download | linux-e9d3c866bf4cdbb6637e6cb268c26dfdf06d8cd3.tar.xz | |
bfq: Fix the missing barrier in __bfq_entity_update_weight_prio
The comment of bfq_group_set_weight says the reading of prio_changed
should happen before the reading of weight, but a memory barrier is
missing here. Add it now, to match the smp_wmb() there.
Signed-off-by: Fam Zheng <zhengfeiran@bytedance.com>
Reviewed-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-wf2q.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index c9ba225081ce..05f0bf4a1144 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -744,6 +744,8 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, } #endif + /* Matches the smp_wmb() in bfq_group_set_weight. */ + smp_rmb(); old_st->wsum -= entity->weight; if (entity->new_weight != entity->orig_weight) { |