dql
struct dql *dql = &q->dql;
dql->last_obj_cnt, dql->num_queued,
dql->adj_limit, dql->num_completed);
(dql->history_head + i) * BITS_PER_LONG)
DQL_HIST_ENT(dql, dql->history_head + i + 1) = 0;
WRITE_ONCE(dql->history_head, now_hi);
map = DQL_HIST_ENT(dql, now_hi);
WRITE_ONCE(DQL_HIST_ENT(dql, now_hi), map | BIT_MASK(now));
static inline void dql_queued(struct dql *dql, unsigned int count)
WRITE_ONCE(dql->last_obj_cnt, count);
dql->num_queued += count;
if (READ_ONCE(dql->stall_thrs))
dql_queue_stall(dql);
static inline int dql_avail(const struct dql *dql)
return READ_ONCE(dql->adj_limit) - READ_ONCE(dql->num_queued);
void dql_completed(struct dql *dql, unsigned int count);
void dql_reset(struct dql *dql);
void dql_init(struct dql *dql, unsigned int hold_time);
#define DQL_HIST_ENT(dql, idx) ((dql)->history[(idx) % DQL_HIST_LEN])
static inline void dql_queue_stall(struct dql *dql)
if (unlikely(now_hi != dql->history_head)) {
dev_queue->dql.min_limit = min_limit;
return dql_avail(&txq->dql);
prefetchw(&dev_queue->dql.num_queued);
prefetchw(&dev_queue->dql.limit);
dql_queued(&dev_queue->dql, bytes);
if (likely(dql_avail(&dev_queue->dql) >= 0))
if (unlikely(dql_avail(&dev_queue->dql) >= 0))
dql_queued(&dev_queue->dql, bytes);
dql_completed(&dev_queue->dql, bytes);
if (unlikely(dql_avail(&dev_queue->dql) < 0))
dql_reset(&q->dql);
struct dql dql;
completed = dql->num_completed + count;
limit = dql->limit;
ovlimit = POSDIFF(num_queued - dql->num_completed, limit);
prev_inprogress = dql->prev_num_queued - dql->num_completed;
all_prev_completed = AFTER_EQ(completed, dql->prev_num_queued);
(dql->prev_ovlimit && all_prev_completed)) {
limit += POSDIFF(completed, dql->prev_num_queued) +
dql->prev_ovlimit;
dql->slack_start_time = jiffies;
dql->lowest_slack = UINT_MAX;
slack = POSDIFF(limit + dql->prev_ovlimit,
2 * (completed - dql->num_completed));
slack_last_objs = dql->prev_ovlimit ?
POSDIFF(dql->prev_last_obj_cnt, dql->prev_ovlimit) : 0;
if (slack < dql->lowest_slack)
dql->lowest_slack = slack;
dql->slack_start_time + dql->slack_hold_time)) {
limit = POSDIFF(limit, dql->lowest_slack);
dql->slack_start_time = jiffies;
dql->lowest_slack = UINT_MAX;
limit = clamp(limit, dql->min_limit, dql->max_limit);
if (limit != dql->limit) {
dql->limit = limit;
static void dql_check_stall(struct dql *dql, unsigned short stall_thrs)
dql->adj_limit = limit + completed;
dql->prev_ovlimit = ovlimit;
dql->prev_last_obj_cnt = READ_ONCE(dql->last_obj_cnt);
dql->num_completed = completed;
dql->prev_num_queued = num_queued;
dql_check_stall(dql, stall_thrs);
void dql_reset(struct dql *dql)
dql->limit = dql->min_limit;
dql->num_queued = 0;
dql->num_completed = 0;
dql->last_obj_cnt = 0;
dql->prev_num_queued = 0;
dql->prev_last_obj_cnt = 0;
dql->prev_ovlimit = 0;
dql->lowest_slack = UINT_MAX;
dql->slack_start_time = jiffies;
dql->last_reap = jiffies;
dql->history_head = jiffies / BITS_PER_LONG;
memset(dql->history, 0, sizeof(dql->history));
void dql_init(struct dql *dql, unsigned int hold_time)
dql->max_limit = DQL_MAX_LIMIT;
dql->min_limit = 0;
dql->slack_hold_time = hold_time;
dql->stall_thrs = 0;
dql_reset(dql);
if (time_after_eq(now, dql->last_reap + stall_thrs)) {
hist_head = READ_ONCE(dql->history_head);
if (time_before(start, dql->last_reap + 1))
start = dql->last_reap + 1;
dql->history))
if (hist_head != READ_ONCE(dql->history_head))
dql->stall_cnt++;
dql->stall_max = max_t(unsigned short, dql->stall_max, now - t);
trace_dql_stall_detected(dql->stall_thrs, now - t,
dql->last_reap, dql->history_head,
now, dql->history);
dql->last_reap = now;
void dql_completed(struct dql *dql, unsigned int count)
num_queued = READ_ONCE(dql->num_queued);
stall_thrs = READ_ONCE(dql->stall_thrs);
BUG_ON(count > num_queued - dql->num_completed);
dql_init(&queue->dql, HZ);
struct dql *dql = &queue->dql;
return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time));
struct dql *dql = &queue->dql;
dql->slack_hold_time = msecs_to_jiffies(value);
struct dql *dql = &queue->dql;
return sysfs_emit(buf, "%u\n", jiffies_to_msecs(dql->stall_thrs));
struct dql *dql = &queue->dql;
if (!dql->stall_thrs && value)
dql->last_reap = jiffies;
dql->stall_thrs = value;
return sysfs_emit(buf, "%u\n", READ_ONCE(queue->dql.stall_max));
WRITE_ONCE(queue->dql.stall_max, 0);
struct dql *dql = &queue->dql;
return sysfs_emit(buf, "%lu\n", dql->stall_cnt);
struct dql *dql = &queue->dql;
return sysfs_emit(buf, "%u\n", dql->num_queued - dql->num_completed);
return bql_show(buf, queue->dql.FIELD); \
return bql_set(buf, len, &queue->dql.FIELD); \