Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-29 06:12:08 +00:00
Code Issues Packages Projects Releases Wiki Activity

blk-throttle: add backlink pointer from throtl_grp to throtl_data

Browse Source 
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@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
This commit is contained in:
Tejun Heo 2013-05-14 13:52:32 -07:00
parent 5b2c16aae0
commit 0f3457f60e
1 changed files with 53 additions and 53 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

106
block/blk-throttle.c
View File

@ -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);