[PATCH 13/33] blk-throttle: add backlink pointer from throtl_grp to throtl_data
Tejun Heo
tj at kernel.org
Mon May 6 22:45:52 UTC 2013
Add throtl_grp->td so that the td (throtl_data) a given tg
(throtl_grp) belongs to can be determined, and remove @td argument
from functions which take both @td and @tg as the former now can be
determined from the latter.
This generally simplifies the code and removes a number of cases where
@td is passed as an argument without being actually used. This will
also help hierarchy support implementation.
While at it, in multi-line conditions, move the logical operators
leading broken lines to the end of the previous line.
Signed-off-by: Tejun Heo <tj at kernel.org>
---
block/blk-throttle.c | 106 +++++++++++++++++++++++++--------------------------
1 file changed, 53 insertions(+), 53 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index e8ef43d..a489391 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -57,6 +57,9 @@ struct throtl_grp {
/* active throtl group service_queue member */
struct rb_node rb_node;
+ /* throtl_data this group belongs to */
+ struct throtl_data *td;
+
/*
* Dispatch time in jiffies. This is the estimated time when group
* will unthrottle and is ready to dispatch more bio. It is used as
@@ -140,11 +143,11 @@ static inline struct throtl_grp *td_root_tg(struct throtl_data *td)
return blkg_to_tg(td->queue->root_blkg);
}
-#define throtl_log_tg(td, tg, fmt, args...) do { \
+#define throtl_log_tg(tg, fmt, args...) do { \
char __pbuf[128]; \
\
blkg_path(tg_to_blkg(tg), __pbuf, sizeof(__pbuf)); \
- blk_add_trace_msg((td)->queue, "throtl %s " fmt, __pbuf, ##args); \
+ blk_add_trace_msg((tg)->td->queue, "throtl %s " fmt, __pbuf, ##args); \
} while (0)
#define throtl_log(td, fmt, args...) \
@@ -193,6 +196,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
unsigned long flags;
RB_CLEAR_NODE(&tg->rb_node);
+ tg->td = blkg->q->td;
bio_list_init(&tg->bio_lists[0]);
bio_list_init(&tg->bio_lists[1]);
@@ -401,36 +405,34 @@ static void throtl_schedule_next_dispatch(struct throtl_data *td)
throtl_schedule_delayed_work(td, sq->first_pending_disptime - jiffies);
}
-static inline void
-throtl_start_new_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw)
{
tg->bytes_disp[rw] = 0;
tg->io_disp[rw] = 0;
tg->slice_start[rw] = jiffies;
tg->slice_end[rw] = jiffies + throtl_slice;
- throtl_log_tg(td, tg, "[%c] new slice start=%lu end=%lu jiffies=%lu",
+ throtl_log_tg(tg, "[%c] new slice start=%lu end=%lu jiffies=%lu",
rw == READ ? 'R' : 'W', tg->slice_start[rw],
tg->slice_end[rw], jiffies);
}
-static inline void throtl_set_slice_end(struct throtl_data *td,
- struct throtl_grp *tg, bool rw, unsigned long jiffy_end)
+static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw,
+ unsigned long jiffy_end)
{
tg->slice_end[rw] = roundup(jiffy_end, throtl_slice);
}
-static inline void throtl_extend_slice(struct throtl_data *td,
- struct throtl_grp *tg, bool rw, unsigned long jiffy_end)
+static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw,
+ unsigned long jiffy_end)
{
tg->slice_end[rw] = roundup(jiffy_end, throtl_slice);
- throtl_log_tg(td, tg, "[%c] extend slice start=%lu end=%lu jiffies=%lu",
+ throtl_log_tg(tg, "[%c] extend slice start=%lu end=%lu jiffies=%lu",
rw == READ ? 'R' : 'W', tg->slice_start[rw],
tg->slice_end[rw], jiffies);
}
/* Determine if previously allocated or extended slice is complete or not */
-static bool
-throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+static bool throtl_slice_used(struct throtl_grp *tg, bool rw)
{
if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw]))
return 0;
@@ -439,8 +441,7 @@ throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw)
}
/* Trim the used slices and adjust slice start accordingly */
-static inline void
-throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
{
unsigned long nr_slices, time_elapsed, io_trim;
u64 bytes_trim, tmp;
@@ -452,7 +453,7 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
* renewed. Don't try to trim the slice if slice is used. A new
* slice will start when appropriate.
*/
- if (throtl_slice_used(td, tg, rw))
+ if (throtl_slice_used(tg, rw))
return;
/*
@@ -463,7 +464,7 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
* is bad because it does not allow new slice to start.
*/
- throtl_set_slice_end(td, tg, rw, jiffies + throtl_slice);
+ throtl_set_slice_end(tg, rw, jiffies + throtl_slice);
time_elapsed = jiffies - tg->slice_start[rw];
@@ -492,14 +493,14 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
tg->slice_start[rw] += nr_slices * throtl_slice;
- throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%llu io=%lu"
+ throtl_log_tg(tg, "[%c] trim slice nr=%lu bytes=%llu io=%lu"
" start=%lu end=%lu jiffies=%lu",
rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim,
tg->slice_start[rw], tg->slice_end[rw], jiffies);
}
-static bool tg_with_in_iops_limit(struct throtl_data *td, struct throtl_grp *tg,
- struct bio *bio, unsigned long *wait)
+static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
{
bool rw = bio_data_dir(bio);
unsigned int io_allowed;
@@ -548,8 +549,8 @@ static bool tg_with_in_iops_limit(struct throtl_data *td, struct throtl_grp *tg,
return 0;
}
-static bool tg_with_in_bps_limit(struct throtl_data *td, struct throtl_grp *tg,
- struct bio *bio, unsigned long *wait)
+static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
{
bool rw = bio_data_dir(bio);
u64 bytes_allowed, extra_bytes, tmp;
@@ -600,8 +601,8 @@ static bool tg_no_rule_group(struct throtl_grp *tg, bool rw) {
* Returns whether one can dispatch a bio or not. Also returns approx number
* of jiffies to wait before this bio is with-in IO rate and can be dispatched
*/
-static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
- struct bio *bio, unsigned long *wait)
+static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
{
bool rw = bio_data_dir(bio);
unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0;
@@ -626,15 +627,15 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
* existing slice to make sure it is at least throtl_slice interval
* long since now.
*/
- if (throtl_slice_used(td, tg, rw))
- throtl_start_new_slice(td, tg, rw);
+ if (throtl_slice_used(tg, rw))
+ throtl_start_new_slice(tg, rw);
else {
if (time_before(tg->slice_end[rw], jiffies + throtl_slice))
- throtl_extend_slice(td, tg, rw, jiffies + throtl_slice);
+ throtl_extend_slice(tg, rw, jiffies + throtl_slice);
}
- if (tg_with_in_bps_limit(td, tg, bio, &bps_wait)
- && tg_with_in_iops_limit(td, tg, bio, &iops_wait)) {
+ if (tg_with_in_bps_limit(tg, bio, &bps_wait) &&
+ tg_with_in_iops_limit(tg, bio, &iops_wait)) {
if (wait)
*wait = 0;
return 1;
@@ -646,7 +647,7 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
*wait = max_wait;
if (time_before(tg->slice_end[rw], jiffies + max_wait))
- throtl_extend_slice(td, tg, rw, jiffies + max_wait);
+ throtl_extend_slice(tg, rw, jiffies + max_wait);
return 0;
}
@@ -707,10 +708,10 @@ static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg)
struct bio *bio;
if ((bio = bio_list_peek(&tg->bio_lists[READ])))
- tg_may_dispatch(td, tg, bio, &read_wait);
+ tg_may_dispatch(tg, bio, &read_wait);
if ((bio = bio_list_peek(&tg->bio_lists[WRITE])))
- tg_may_dispatch(td, tg, bio, &write_wait);
+ tg_may_dispatch(tg, bio, &write_wait);
min_wait = min(read_wait, write_wait);
disptime = jiffies + min_wait;
@@ -721,8 +722,8 @@ static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg)
throtl_enqueue_tg(td, tg);
}
-static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg,
- bool rw, struct bio_list *bl)
+static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw,
+ struct bio_list *bl)
{
struct bio *bio;
@@ -731,18 +732,17 @@ static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg,
/* Drop bio reference on blkg */
blkg_put(tg_to_blkg(tg));
- BUG_ON(td->nr_queued[rw] <= 0);
- td->nr_queued[rw]--;
+ BUG_ON(tg->td->nr_queued[rw] <= 0);
+ tg->td->nr_queued[rw]--;
throtl_charge_bio(tg, bio);
bio_list_add(bl, bio);
bio->bi_rw |= REQ_THROTTLED;
- throtl_trim_slice(td, tg, rw);
+ throtl_trim_slice(tg, rw);
}
-static int throtl_dispatch_tg(struct throtl_data *td, struct throtl_grp *tg,
- struct bio_list *bl)
+static int throtl_dispatch_tg(struct throtl_grp *tg, struct bio_list *bl)
{
unsigned int nr_reads = 0, nr_writes = 0;
unsigned int max_nr_reads = throtl_grp_quantum*3/4;
@@ -751,20 +751,20 @@ static int throtl_dispatch_tg(struct throtl_data *td, struct throtl_grp *tg,
/* Try to dispatch 75% READS and 25% WRITES */
- while ((bio = bio_list_peek(&tg->bio_lists[READ]))
- && tg_may_dispatch(td, tg, bio, NULL)) {
+ while ((bio = bio_list_peek(&tg->bio_lists[READ])) &&
+ tg_may_dispatch(tg, bio, NULL)) {
- tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl);
+ tg_dispatch_one_bio(tg, bio_data_dir(bio), bl);
nr_reads++;
if (nr_reads >= max_nr_reads)
break;
}
- while ((bio = bio_list_peek(&tg->bio_lists[WRITE]))
- && tg_may_dispatch(td, tg, bio, NULL)) {
+ while ((bio = bio_list_peek(&tg->bio_lists[WRITE])) &&
+ tg_may_dispatch(tg, bio, NULL)) {
- tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl);
+ tg_dispatch_one_bio(tg, bio_data_dir(bio), bl);
nr_writes++;
if (nr_writes >= max_nr_writes)
@@ -791,7 +791,7 @@ static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl)
throtl_dequeue_tg(td, tg);
- nr_disp += throtl_dispatch_tg(td, tg, bl);
+ nr_disp += throtl_dispatch_tg(tg, bl);
if (tg->nr_queued[0] || tg->nr_queued[1])
tg_update_disptime(td, tg);
@@ -933,7 +933,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
else
*(unsigned int *)((void *)tg + cft->private) = ctx.v;
- throtl_log_tg(td, tg, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
+ throtl_log_tg(tg, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
tg->bps[READ], tg->bps[WRITE],
tg->iops[READ], tg->iops[WRITE]);
@@ -945,8 +945,8 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
* that a group's limit are dropped suddenly and we don't want to
* account recently dispatched IO with new low rate.
*/
- throtl_start_new_slice(td, tg, 0);
- throtl_start_new_slice(td, tg, 1);
+ throtl_start_new_slice(tg, 0);
+ throtl_start_new_slice(tg, 1);
if (tg->flags & THROTL_TG_PENDING) {
tg_update_disptime(td, tg);
@@ -1076,7 +1076,7 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
}
/* Bio is with-in rate limit of group */
- if (tg_may_dispatch(td, tg, bio, NULL)) {
+ if (tg_may_dispatch(tg, bio, NULL)) {
throtl_charge_bio(tg, bio);
/*
@@ -1090,12 +1090,12 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
*
* So keep on trimming slice even if bio is not queued.
*/
- throtl_trim_slice(td, tg, rw);
+ throtl_trim_slice(tg, rw);
goto out_unlock;
}
queue_bio:
- throtl_log_tg(td, tg, "[%c] bio. bdisp=%llu sz=%u bps=%llu"
+ throtl_log_tg(tg, "[%c] bio. bdisp=%llu sz=%u bps=%llu"
" iodisp=%u iops=%u queued=%d/%d",
rw == READ ? 'R' : 'W',
tg->bytes_disp[rw], bio->bi_size, tg->bps[rw],
@@ -1142,9 +1142,9 @@ void blk_throtl_drain(struct request_queue *q)
throtl_dequeue_tg(td, tg);
while ((bio = bio_list_peek(&tg->bio_lists[READ])))
- tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+ tg_dispatch_one_bio(tg, bio_data_dir(bio), &bl);
while ((bio = bio_list_peek(&tg->bio_lists[WRITE])))
- tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+ tg_dispatch_one_bio(tg, bio_data_dir(bio), &bl);
}
spin_unlock_irq(q->queue_lock);
--
1.8.1.4
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