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authorOmar Sandoval <osandov@fb.com>2018-05-09 11:08:53 +0200
committerJens Axboe <axboe@kernel.dk>2018-05-09 16:33:09 +0200
commit522a777566f5669606a1227bf13f3fb40963780b (patch)
tree7d37c9d591e5a9abb4fd1209f1c503ae1a0e8475 /block/blk-core.c
parentblock: move blk_stat_add() to __blk_mq_end_request() (diff)
downloadlinux-522a777566f5669606a1227bf13f3fb40963780b.tar.xz
linux-522a777566f5669606a1227bf13f3fb40963780b.zip
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 <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c17
1 files changed, 8 insertions, 9 deletions
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);