From 522a777566f5669606a1227bf13f3fb40963780b Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 9 May 2018 02:08:53 -0700 Subject: block: consolidate struct request timestamp fields Currently, struct request has four timestamp fields: - A start time, set at get_request time, in jiffies, used for iostats - An I/O start time, set at start_request time, in ktime nanoseconds, used for blk-stats (i.e., wbt, kyber, hybrid polling) - Another start time and another I/O start time, used for cfq and bfq These can all be consolidated into one start time and one I/O start time, both in ktime nanoseconds, shaving off up to 16 bytes from struct request depending on the kernel config. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-core.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) (limited to 'block/blk-core.c') diff --git a/block/blk-core.c b/block/blk-core.c index 33d5c7d85da1..1418a1ccd80d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -196,8 +196,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq) RB_CLEAR_NODE(&rq->rb_node); rq->tag = -1; rq->internal_tag = -1; - rq->start_time = jiffies; - set_start_time_ns(rq); + rq->start_time_ns = ktime_get_ns(); rq->part = NULL; seqcount_init(&rq->gstate_seq); u64_stats_init(&rq->aborted_gstate_sync); @@ -2726,7 +2725,7 @@ void blk_account_io_completion(struct request *req, unsigned int bytes) } } -void blk_account_io_done(struct request *req) +void blk_account_io_done(struct request *req, u64 now) { /* * Account IO completion. flush_rq isn't accounted as a @@ -2734,11 +2733,12 @@ void blk_account_io_done(struct request *req) * containing request is enough. */ if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) { - unsigned long duration = jiffies - req->start_time; + unsigned long duration; const int rw = rq_data_dir(req); struct hd_struct *part; int cpu; + duration = nsecs_to_jiffies(now - req->start_time_ns); cpu = part_stat_lock(); part = req->part; @@ -2969,10 +2969,8 @@ static void blk_dequeue_request(struct request *rq) * and to it is freed is accounted as io that is in progress at * the driver side. */ - if (blk_account_rq(rq)) { + if (blk_account_rq(rq)) q->in_flight[rq_is_sync(rq)]++; - set_io_start_time_ns(rq); - } } /** @@ -3192,12 +3190,13 @@ EXPORT_SYMBOL_GPL(blk_unprep_request); void blk_finish_request(struct request *req, blk_status_t error) { struct request_queue *q = req->q; + u64 now = ktime_get_ns(); lockdep_assert_held(req->q->queue_lock); WARN_ON_ONCE(q->mq_ops); if (req->rq_flags & RQF_STATS) - blk_stat_add(req); + blk_stat_add(req, now); if (req->rq_flags & RQF_QUEUED) blk_queue_end_tag(q, req); @@ -3212,7 +3211,7 @@ void blk_finish_request(struct request *req, blk_status_t error) if (req->rq_flags & RQF_DONTPREP) blk_unprep_request(req); - blk_account_io_done(req); + blk_account_io_done(req, now); if (req->end_io) { wbt_done(req->q->rq_wb, req); -- cgit v1.2.3