[PATCH 14/31] blk-throttle: pass around throtl_service_queue instead of throtl_data

From: Tejun Heo
Date: Wed May 01 2013 - 20:43:57 EST


throtl_service_queue will be used as the basic block to implement
hierarchy support. Pass around throtl_service_queue *sq instead of
throtl_data *td in the following functions which will be used across
multiple levels of hierarchy.

* [__]throtl_enqueue/dequeue_tg()

* throtl_add_bio_tg()

* tg_update_disptime()

* throtl_select_dispatch()

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
block/blk-throttle.c | 53 +++++++++++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 25 deletions(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 6aae239..a81e10b 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -352,31 +352,33 @@ static void tg_service_queue_add(struct throtl_service_queue *sq,
rb_insert_color(&tg->rb_node, &sq->pending_tree);
}

-static void __throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg)
+static void __throtl_enqueue_tg(struct throtl_service_queue *sq,
+ struct throtl_grp *tg)
{
- struct throtl_service_queue *sq = &td->service_queue;
-
tg_service_queue_add(sq, tg);
tg->flags |= THROTL_TG_PENDING;
sq->nr_pending++;
}

-static void throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg)
+static void throtl_enqueue_tg(struct throtl_service_queue *sq,
+ struct throtl_grp *tg)
{
if (!(tg->flags & THROTL_TG_PENDING))
- __throtl_enqueue_tg(td, tg);
+ __throtl_enqueue_tg(sq, tg);
}

-static void __throtl_dequeue_tg(struct throtl_data *td, struct throtl_grp *tg)
+static void __throtl_dequeue_tg(struct throtl_service_queue *sq,
+ struct throtl_grp *tg)
{
- throtl_rb_erase(&tg->rb_node, &td->service_queue);
+ throtl_rb_erase(&tg->rb_node, sq);
tg->flags &= ~THROTL_TG_PENDING;
}

-static void throtl_dequeue_tg(struct throtl_data *td, struct throtl_grp *tg)
+static void throtl_dequeue_tg(struct throtl_service_queue *sq,
+ struct throtl_grp *tg)
{
if (tg->flags & THROTL_TG_PENDING)
- __throtl_dequeue_tg(td, tg);
+ __throtl_dequeue_tg(sq, tg);
}

/* Call with queue lock held */
@@ -689,8 +691,8 @@ static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
throtl_update_dispatch_stats(tg_to_blkg(tg), bio->bi_size, bio->bi_rw);
}

-static void throtl_add_bio_tg(struct throtl_data *td, struct throtl_grp *tg,
- struct bio *bio)
+static void throtl_add_bio_tg(struct throtl_service_queue *sq,
+ struct throtl_grp *tg, struct bio *bio)
{
bool rw = bio_data_dir(bio);

@@ -698,11 +700,12 @@ static void throtl_add_bio_tg(struct throtl_data *td, struct throtl_grp *tg,
/* Take a bio reference on tg */
blkg_get(tg_to_blkg(tg));
tg->nr_queued[rw]++;
- td->nr_queued[rw]++;
- throtl_enqueue_tg(td, tg);
+ tg->td->nr_queued[rw]++;
+ throtl_enqueue_tg(sq, tg);
}

-static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg)
+static void tg_update_disptime(struct throtl_service_queue *sq,
+ struct throtl_grp *tg)
{
unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime;
struct bio *bio;
@@ -717,9 +720,9 @@ static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg)
disptime = jiffies + min_wait;

/* Update dispatch time */
- throtl_dequeue_tg(td, tg);
+ throtl_dequeue_tg(sq, tg);
tg->disptime = disptime;
- throtl_enqueue_tg(td, tg);
+ throtl_enqueue_tg(sq, tg);
}

static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw,
@@ -774,11 +777,11 @@ static int throtl_dispatch_tg(struct throtl_grp *tg, struct bio_list *bl)
return nr_reads + nr_writes;
}

-static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl)
+static int throtl_select_dispatch(struct throtl_service_queue *sq,
+ struct bio_list *bl)
{
unsigned int nr_disp = 0;
struct throtl_grp *tg;
- struct throtl_service_queue *sq = &td->service_queue;

while (1) {
tg = throtl_rb_first(sq);
@@ -789,12 +792,12 @@ static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl)
if (time_before(jiffies, tg->disptime))
break;

- throtl_dequeue_tg(td, tg);
+ throtl_dequeue_tg(sq, tg);

nr_disp += throtl_dispatch_tg(tg, bl);

if (tg->nr_queued[0] || tg->nr_queued[1])
- tg_update_disptime(td, tg);
+ tg_update_disptime(sq, tg);

if (nr_disp >= throtl_quantum)
break;
@@ -822,7 +825,7 @@ void blk_throtl_dispatch_work_fn(struct work_struct *work)
td->nr_queued[READ] + td->nr_queued[WRITE],
td->nr_queued[READ], td->nr_queued[WRITE]);

- nr_disp = throtl_select_dispatch(td, &bio_list_on_stack);
+ nr_disp = throtl_select_dispatch(&td->service_queue, &bio_list_on_stack);

if (nr_disp)
throtl_log(td, "bios disp=%u", nr_disp);
@@ -949,7 +952,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
throtl_start_new_slice(tg, 1);

if (tg->flags & THROTL_TG_PENDING) {
- tg_update_disptime(td, tg);
+ tg_update_disptime(&td->service_queue, tg);
throtl_schedule_next_dispatch(td);
}

@@ -1106,11 +1109,11 @@ queue_bio:
tg->nr_queued[READ], tg->nr_queued[WRITE]);

bio_associate_current(bio);
- throtl_add_bio_tg(q->td, tg, bio);
+ throtl_add_bio_tg(&q->td->service_queue, tg, bio);
throttled = true;

if (update_disptime) {
- tg_update_disptime(td, tg);
+ tg_update_disptime(&td->service_queue, tg);
throtl_schedule_next_dispatch(td);
}

@@ -1142,7 +1145,7 @@ void blk_throtl_drain(struct request_queue *q)
bio_list_init(&bl);

while ((tg = throtl_rb_first(sq))) {
- throtl_dequeue_tg(td, tg);
+ throtl_dequeue_tg(sq, tg);

while ((bio = bio_list_peek(&tg->bio_lists[READ])))
tg_dispatch_one_bio(tg, bio_data_dir(bio), &bl);
--
1.8.1.4

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