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-rw-r--r--block/mq-deadline.c58
1 files changed, 16 insertions, 42 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index a09761cbdf12..36920670dccc 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -31,11 +31,6 @@
*/
static const int read_expire = HZ / 2; /* max time before a read is submitted. */
static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
-/*
- * Time after which to dispatch lower priority requests even if higher
- * priority requests are pending.
- */
-static const int aging_expire = 10 * HZ;
static const int writes_starved = 2; /* max times reads can starve a write */
static const int fifo_batch = 16; /* # of sequential requests treated as one
by the above parameters. For throughput. */
@@ -103,7 +98,6 @@ struct deadline_data {
int writes_starved;
int front_merges;
u32 async_depth;
- int aging_expire;
spinlock_t lock;
spinlock_t zone_lock;
@@ -369,11 +363,10 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
/*
* deadline_dispatch_requests selects the best request according to
- * read/write expire, fifo_batch, etc and with a start time <= @latest.
+ * read/write expire, fifo_batch, etc
*/
static struct request *__dd_dispatch_request(struct deadline_data *dd,
- struct dd_per_prio *per_prio,
- u64 latest_start_ns)
+ struct dd_per_prio *per_prio)
{
struct request *rq, *next_rq;
enum dd_data_dir data_dir;
@@ -385,8 +378,6 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd,
if (!list_empty(&per_prio->dispatch)) {
rq = list_first_entry(&per_prio->dispatch, struct request,
queuelist);
- if (rq->start_time_ns > latest_start_ns)
- return NULL;
list_del_init(&rq->queuelist);
goto done;
}
@@ -464,8 +455,6 @@ dispatch_find_request:
dd->batching = 0;
dispatch_request:
- if (rq->start_time_ns > latest_start_ns)
- return NULL;
/*
* rq is the selected appropriate request.
*/
@@ -494,32 +483,15 @@ done:
static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
{
struct deadline_data *dd = hctx->queue->elevator->elevator_data;
- const u64 now_ns = ktime_get_ns();
- struct request *rq = NULL;
+ struct request *rq;
enum dd_prio prio;
spin_lock(&dd->lock);
- /*
- * Start with dispatching requests whose deadline expired more than
- * aging_expire jiffies ago.
- */
- for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) {
- rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns -
- jiffies_to_nsecs(dd->aging_expire));
- if (rq)
- goto unlock;
- }
- /*
- * Next, dispatch requests in priority order. Ignore lower priority
- * requests if any higher priority requests are pending.
- */
for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
- rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns);
- if (rq || dd_queued(dd, prio))
+ rq = __dd_dispatch_request(dd, &dd->per_prio[prio]);
+ if (rq)
break;
}
-
-unlock:
spin_unlock(&dd->lock);
return rq;
@@ -620,7 +592,6 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e)
dd->front_merges = 1;
dd->last_dir = DD_WRITE;
dd->fifo_batch = fifo_batch;
- dd->aging_expire = aging_expire;
spin_lock_init(&dd->lock);
spin_lock_init(&dd->zone_lock);
@@ -711,6 +682,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
prio = ioprio_class_to_prio[ioprio_class];
dd_count(dd, inserted, prio);
+ rq->elv.priv[0] = (void *)(uintptr_t)1;
if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
blk_mq_free_requests(&free);
@@ -759,12 +731,10 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
spin_unlock(&dd->lock);
}
-/*
- * Nothing to do here. This is defined only to ensure that .finish_request
- * method is called upon request completion.
- */
+/* Callback from inside blk_mq_rq_ctx_init(). */
static void dd_prepare_request(struct request *rq)
{
+ rq->elv.priv[0] = NULL;
}
/*
@@ -791,7 +761,14 @@ static void dd_finish_request(struct request *rq)
const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
struct dd_per_prio *per_prio = &dd->per_prio[prio];
- dd_count(dd, completed, prio);
+ /*
+ * The block layer core may call dd_finish_request() without having
+ * called dd_insert_requests(). Hence only update statistics for
+ * requests for which dd_insert_requests() has been called. See also
+ * blk_mq_request_bypass_insert().
+ */
+ if (rq->elv.priv[0])
+ dd_count(dd, completed, prio);
if (blk_queue_is_zoned(q)) {
unsigned long flags;
@@ -836,7 +813,6 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \
#define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
-SHOW_JIFFIES(deadline_aging_expire_show, dd->aging_expire);
SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
SHOW_INT(deadline_front_merges_show, dd->front_merges);
SHOW_INT(deadline_async_depth_show, dd->front_merges);
@@ -866,7 +842,6 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)
STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
-STORE_JIFFIES(deadline_aging_expire_store, &dd->aging_expire, 0, INT_MAX);
STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
STORE_INT(deadline_async_depth_store, &dd->front_merges, 1, INT_MAX);
@@ -885,7 +860,6 @@ static struct elv_fs_entry deadline_attrs[] = {
DD_ATTR(front_merges),
DD_ATTR(async_depth),
DD_ATTR(fifo_batch),
- DD_ATTR(aging_expire),
__ATTR_NULL
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 23:56:33 +0000