From: Federico Gavioli <f.gavioli97@xxxxxxxxx>
This patch implements the code to gather the content of the
independent_access_ranges structure from the request_queue and copy
it into the queue's bfq_data. This copy is done at queue initialization.
We copy the access ranges into the bfq_data to avoid taking the queue
lock each time we access the ranges.
This implementation, however, puts a limit to the maximum independent
ranges supported by the scheduler. Such a limit is equal to the constant
BFQ_MAX_ACTUATORS. This limit was placed to avoid the allocation of
dynamic memory.
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Co-developed-by: Rory Chen <rory.c.chen@xxxxxxxxxxx>
Signed-off-by: Rory Chen <rory.c.chen@xxxxxxxxxxx>
Signed-off-by: Federico Gavioli <f.gavioli97@xxxxxxxxx>
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
---
block/bfq-iosched.c | 59 +++++++++++++++++++++++++++++++++++++++------
block/bfq-iosched.h | 8 +++++-
2 files changed, 58 insertions(+), 9 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index e6684442d775..b5ed666be0e6 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -1839,10 +1839,25 @@ static bool bfq_bfqq_higher_class_or_weight(struct bfq_queue *bfqq,
*/
static unsigned int bfq_actuator_index(struct bfq_data *bfqd, struct bio *bio)
{
- /*
- * Multi-actuator support not complete yet, so always return 0
- * for the moment (to keep incomplete mechanisms off).
- */
+ unsigned int i;
+ sector_t end;
+
+ /* no search needed if one or zero ranges present */
+ if (bfqd->num_actuators == 1)
+ return 0;
+
+ /* bio_end_sector(bio) gives the sector after the last one */
+ end = bio_end_sector(bio) - 1;
+
+ for (i = 0; i < bfqd->num_actuators; i++) {
+ if (end >= bfqd->sector[i] &&
+ end < bfqd->sector[i] + bfqd->nr_sectors[i])
+ return i;
+ }
+
+ WARN_ONCE(true,
+ "bfq_actuator_index: bio sector out of ranges: end=%llu\n",
+ end);
return 0;
}
@@ -7159,6 +7174,8 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
{
struct bfq_data *bfqd;
struct elevator_queue *eq;
+ unsigned int i;
+ struct blk_independent_access_ranges *ia_ranges = q->disk->ia_ranges;
eq = elevator_alloc(q, e);
if (!eq)
@@ -7201,12 +7218,38 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
bfqd->queue = q;
+ bfqd->num_actuators = 1;
/*
- * Multi-actuator support not complete yet, unconditionally
- * set to only one actuator for the moment (to keep incomplete
- * mechanisms off).
+ * If the disk supports multiple actuators, copy independent
+ * access ranges from the request queue structure.
*/
- bfqd->num_actuators = 1;
+ spin_lock_irq(&q->queue_lock);
+ if (ia_ranges) {
+ /*
+ * Check if the disk ia_ranges size exceeds the current bfq
+ * actuator limit.
+ */
+ if (ia_ranges->nr_ia_ranges > BFQ_MAX_ACTUATORS) {
+ pr_crit("nr_ia_ranges higher than act limit: iars=%d, max=%d.\n",
+ ia_ranges->nr_ia_ranges, BFQ_MAX_ACTUATORS);
+ pr_crit("Falling back to single actuator mode.\n");
+ } else {
+ bfqd->num_actuators = ia_ranges->nr_ia_ranges;
+
+ for (i = 0; i < bfqd->num_actuators; i++) {
+ bfqd->sector[i] = ia_ranges->ia_range[i].sector;
+ bfqd->nr_sectors[i] =
+ ia_ranges->ia_range[i].nr_sectors;
+ }
+ }
+ }
+
+ /* Otherwise use single-actuator dev info */
+ if (bfqd->num_actuators == 1) {
+ bfqd->sector[0] = 0;
+ bfqd->nr_sectors[0] = get_capacity(q->disk);
+ }
+ spin_unlock_irq(&q->queue_lock);
INIT_LIST_HEAD(&bfqd->dispatch);
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index 1450990dba32..953980de6b4b 100644
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -810,7 +810,13 @@ struct bfq_data {
* case of single-actuator drives.
*/
unsigned int num_actuators;
-
+ /*
+ * Disk independent access ranges for each actuator
+ * in this device.
+ */
+ sector_t sector[BFQ_MAX_ACTUATORS];
+ sector_t nr_sectors[BFQ_MAX_ACTUATORS];
+ struct blk_independent_access_range ia_ranges[BFQ_MAX_ACTUATORS];
};
enum bfqq_state_flags {
--
2.20.1
