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| author | Liu Bo <bo.liu@linux.alibaba.com> | 2019-01-25 08:12:48 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-02-08 12:42:27 -0700 |
| commit | 391f552af213985d3d324c60004475759a7030c5 (patch) | |
| tree | f4f2268199a07c7343b4989371140227358f51c2 /block/blk-iolatency.c | |
| parent | 8c772a9bfc7c07c76f4a58b58910452fbb20843b (diff) | |
| download | lwn-391f552af213985d3d324c60004475759a7030c5.tar.gz lwn-391f552af213985d3d324c60004475759a7030c5.zip | |
Blk-iolatency: warn on negative inflight IO counter
This is to catch any unexpected negative value of inflight IO counter.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 1893686a9c1f..2620baa1f699 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -592,6 +592,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio) u64 now = ktime_to_ns(ktime_get()); bool issue_as_root = bio_issue_as_root_blkg(bio); bool enabled = false; + int inflight = 0; blkg = bio->bi_blkg; if (!blkg || !bio_flagged(bio, BIO_TRACKED)) @@ -613,7 +614,8 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio) } rqw = &iolat->rq_wait; - atomic_dec(&rqw->inflight); + inflight = atomic_dec_return(&rqw->inflight); + WARN_ON_ONCE(inflight < 0); if (iolat->min_lat_nsec == 0) goto next; iolatency_record_time(iolat, &bio->bi_issue, now, |