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-rw-r--r--block/blk-throttle.c59
1 files changed, 36 insertions, 23 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index fee3325edf27..36ba61c5cdbd 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -15,10 +15,10 @@
#include "blk-cgroup-rwstat.h"
/* Max dispatch from a group in 1 round */
-static int throtl_grp_quantum = 8;
+#define THROTL_GRP_QUANTUM 8
/* Total max dispatch from all groups in one round */
-static int throtl_quantum = 32;
+#define THROTL_QUANTUM 32
/* Throttling is performed over a slice and after that slice is renewed */
#define DFL_THROTL_SLICE_HD (HZ / 10)
@@ -150,7 +150,7 @@ struct throtl_grp {
/* user configured IOPS limits */
unsigned int iops_conf[2][LIMIT_CNT];
- /* Number of bytes disptached in current slice */
+ /* Number of bytes dispatched in current slice */
uint64_t bytes_disp[2];
/* Number of bio's dispatched in current slice */
unsigned int io_disp[2];
@@ -852,7 +852,7 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
/*
* A bio has been dispatched. Also adjust slice_end. It might happen
* that initially cgroup limit was very low resulting in high
- * slice_end, but later limit was bumped up and bio was dispached
+ * slice_end, but later limit was bumped up and bio was dispatched
* sooner, then we need to reduce slice_end. A high bogus slice_end
* is bad because it does not allow new slice to start.
*/
@@ -894,13 +894,19 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
}
static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
- unsigned long *wait)
+ u32 iops_limit, unsigned long *wait)
{
bool rw = bio_data_dir(bio);
unsigned int io_allowed;
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
u64 tmp;
+ if (iops_limit == UINT_MAX) {
+ if (wait)
+ *wait = 0;
+ return true;
+ }
+
jiffy_elapsed = jiffies - tg->slice_start[rw];
/* Round up to the next throttle slice, wait time must be nonzero */
@@ -913,7 +919,7 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
* have been trimmed.
*/
- tmp = (u64)tg_iops_limit(tg, rw) * jiffy_elapsed_rnd;
+ tmp = (u64)iops_limit * jiffy_elapsed_rnd;
do_div(tmp, HZ);
if (tmp > UINT_MAX)
@@ -936,13 +942,19 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
}
static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio,
- unsigned long *wait)
+ u64 bps_limit, unsigned long *wait)
{
bool rw = bio_data_dir(bio);
u64 bytes_allowed, extra_bytes, tmp;
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
unsigned int bio_size = throtl_bio_data_size(bio);
+ if (bps_limit == U64_MAX) {
+ if (wait)
+ *wait = 0;
+ return true;
+ }
+
jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
/* Slice has just started. Consider one slice interval */
@@ -951,7 +963,7 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio,
jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice);
- tmp = tg_bps_limit(tg, rw) * jiffy_elapsed_rnd;
+ tmp = bps_limit * jiffy_elapsed_rnd;
do_div(tmp, HZ);
bytes_allowed = tmp;
@@ -963,7 +975,7 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio,
/* Calc approx time to dispatch */
extra_bytes = tg->bytes_disp[rw] + bio_size - bytes_allowed;
- jiffy_wait = div64_u64(extra_bytes * HZ, tg_bps_limit(tg, rw));
+ jiffy_wait = div64_u64(extra_bytes * HZ, bps_limit);
if (!jiffy_wait)
jiffy_wait = 1;
@@ -987,6 +999,8 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio,
{
bool rw = bio_data_dir(bio);
unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0;
+ u64 bps_limit = tg_bps_limit(tg, rw);
+ u32 iops_limit = tg_iops_limit(tg, rw);
/*
* Currently whole state machine of group depends on first bio
@@ -998,8 +1012,7 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio,
bio != throtl_peek_queued(&tg->service_queue.queued[rw]));
/* If tg->bps = -1, then BW is unlimited */
- if (tg_bps_limit(tg, rw) == U64_MAX &&
- tg_iops_limit(tg, rw) == UINT_MAX) {
+ if (bps_limit == U64_MAX && iops_limit == UINT_MAX) {
if (wait)
*wait = 0;
return true;
@@ -1021,8 +1034,8 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio,
jiffies + tg->td->throtl_slice);
}
- if (tg_with_in_bps_limit(tg, bio, &bps_wait) &&
- tg_with_in_iops_limit(tg, bio, &iops_wait)) {
+ if (tg_with_in_bps_limit(tg, bio, bps_limit, &bps_wait) &&
+ tg_with_in_iops_limit(tg, bio, iops_limit, &iops_wait)) {
if (wait)
*wait = 0;
return true;
@@ -1082,7 +1095,7 @@ static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn,
* If @tg doesn't currently have any bios queued in the same
* direction, queueing @bio can change when @tg should be
* dispatched. Mark that @tg was empty. This is automatically
- * cleaered on the next tg_update_disptime().
+ * cleared on the next tg_update_disptime().
*/
if (!sq->nr_queued[rw])
tg->flags |= THROTL_TG_WAS_EMPTY;
@@ -1175,8 +1188,8 @@ static int throtl_dispatch_tg(struct throtl_grp *tg)
{
struct throtl_service_queue *sq = &tg->service_queue;
unsigned int nr_reads = 0, nr_writes = 0;
- unsigned int max_nr_reads = throtl_grp_quantum*3/4;
- unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads;
+ unsigned int max_nr_reads = THROTL_GRP_QUANTUM * 3 / 4;
+ unsigned int max_nr_writes = THROTL_GRP_QUANTUM - max_nr_reads;
struct bio *bio;
/* Try to dispatch 75% READS and 25% WRITES */
@@ -1226,7 +1239,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
if (sq->nr_queued[0] || sq->nr_queued[1])
tg_update_disptime(tg);
- if (nr_disp >= throtl_quantum)
+ if (nr_disp >= THROTL_QUANTUM)
break;
}
@@ -1303,7 +1316,7 @@ again:
}
}
} else {
- /* reached the top-level, queue issueing */
+ /* reached the top-level, queue issuing */
queue_work(kthrotld_workqueue, &td->dispatch_work);
}
out_unlock:
@@ -1314,8 +1327,8 @@ out_unlock:
* blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work
* @work: work item being executed
*
- * This function is queued for execution when bio's reach the bio_lists[]
- * of throtl_data->service_queue. Those bio's are ready and issued by this
+ * This function is queued for execution when bios reach the bio_lists[]
+ * of throtl_data->service_queue. Those bios are ready and issued by this
* function.
*/
static void blk_throtl_dispatch_work_fn(struct work_struct *work)
@@ -1428,8 +1441,8 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
* 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(tg, 0);
- throtl_start_new_slice(tg, 1);
+ throtl_start_new_slice(tg, READ);
+ throtl_start_new_slice(tg, WRITE);
if (tg->flags & THROTL_TG_PENDING) {
tg_update_disptime(tg);
@@ -2230,7 +2243,7 @@ again:
/*
* @bio passed through this layer without being throttled.
- * Climb up the ladder. If we''re already at the top, it
+ * Climb up the ladder. If we're already at the top, it
* can be executed directly.
*/
qn = &tg->qnode_on_parent[rw];
generated by cgit (git 2.34.1) at 2025-02-28 20:10:48 +0000