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| author | Tejun Heo <tj@kernel.org> | 2018-01-09 19:29:51 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-01-09 19:31:15 +0300 |
| commit | 634f9e4631a88025d3b90c1884e9a1b6a13d01d2 (patch) | |
| tree | 181882ff0dc0d5b0844ede83e2cfc954e28df69f /block/blk-mq.c | |
| parent | 358f70da49d77c43f2ca11b5da584213b2add29c (diff) | |
| download | linux-634f9e4631a88025d3b90c1884e9a1b6a13d01d2.tar.xz | |
blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq
After the recent updates to use generation number and state based
synchronization, blk-mq no longer depends on REQ_ATOM_COMPLETE except
to avoid firing the same timeout multiple times.
Remove all REQ_ATOM_COMPLETE usages and use a new rq_flags flag
RQF_MQ_TIMEOUT_EXPIRED to avoid firing the same timeout multiple
times. This removes atomic bitops from hot paths too.
v2: Removed blk_clear_rq_complete() from blk_mq_rq_timed_out().
v3: Added RQF_MQ_TIMEOUT_EXPIRED flag.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "jianchao.wang" <jianchao.w.wang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 90f6910a83f6..d1000c6cbec6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -634,8 +634,7 @@ void blk_mq_complete_request(struct request *rq) * hctx_lock() covers both issue and completion paths. */ hctx_lock(hctx, &srcu_idx); - if (blk_mq_rq_aborted_gstate(rq) != rq->gstate && - !blk_mark_rq_complete(rq)) + if (blk_mq_rq_aborted_gstate(rq) != rq->gstate) __blk_mq_complete_request(rq); hctx_unlock(hctx, srcu_idx); } @@ -685,8 +684,6 @@ void blk_mq_start_request(struct request *rq) preempt_enable(); set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); - if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) - clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); if (q->dma_drain_size && blk_rq_bytes(rq)) { /* @@ -837,6 +834,8 @@ static void blk_mq_rq_timed_out(struct request *req, bool reserved) if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) return; + req->rq_flags |= RQF_MQ_TIMEOUT_EXPIRED; + if (ops->timeout) ret = ops->timeout(req, reserved); @@ -852,7 +851,6 @@ static void blk_mq_rq_timed_out(struct request *req, bool reserved) */ blk_mq_rq_update_aborted_gstate(req, 0); blk_add_timer(req); - blk_clear_rq_complete(req); break; case BLK_EH_NOT_HANDLED: break; @@ -871,7 +869,8 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, might_sleep(); - if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) + if ((rq->rq_flags & RQF_MQ_TIMEOUT_EXPIRED) || + !test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) return; /* read coherent snapshots of @rq->state_gen and @rq->deadline */ @@ -906,8 +905,8 @@ static void blk_mq_terminate_expired(struct blk_mq_hw_ctx *hctx, * now guaranteed to see @rq->aborted_gstate and yield. If * @rq->aborted_gstate still matches @rq->gstate, @rq is ours. */ - if (READ_ONCE(rq->gstate) == rq->aborted_gstate && - !blk_mark_rq_complete(rq)) + if (!(rq->rq_flags & RQF_MQ_TIMEOUT_EXPIRED) && + READ_ONCE(rq->gstate) == rq->aborted_gstate) blk_mq_rq_timed_out(rq, reserved); } |