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authorJens Axboe <axboe@fb.com>2017-02-22 13:19:45 -0700
committerJens Axboe <axboe@fb.com>2017-02-22 13:19:45 -0700
commitb86dd815ff74ab9eda474d1c28428ac0db2c3032 (patch)
treed2492456261c6394b10ec03e53a6d75180986ef6
parenteed64951f15d63beac75e0f848ac03c14f8a4a6c (diff)
downloadlinux-0-day-b86dd815ff74ab9eda474d1c28428ac0db2c3032.tar.gz
block: get rid of blk-mq default scheduler choice Kconfig entries
The wording in the entries were poor and not understandable by even deities. Kill the selection for default block scheduler, and impose a policy with sane defaults. Architected-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/Kconfig.iosched44
-rw-r--r--block/blk-mq-sched.c9
-rw-r--r--block/elevator.c19
3 files changed, 13 insertions, 59 deletions
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 0715ce9..58fc868 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -69,50 +69,6 @@ config MQ_IOSCHED_DEADLINE
---help---
MQ version of the deadline IO scheduler.
-config MQ_IOSCHED_NONE
- bool
- default y
-
-choice
- prompt "Default single-queue blk-mq I/O scheduler"
- default DEFAULT_SQ_NONE
- help
- Select the I/O scheduler which will be used by default for blk-mq
- managed block devices with a single queue.
-
- config DEFAULT_SQ_DEADLINE
- bool "MQ Deadline" if MQ_IOSCHED_DEADLINE=y
-
- config DEFAULT_SQ_NONE
- bool "None"
-
-endchoice
-
-config DEFAULT_SQ_IOSCHED
- string
- default "mq-deadline" if DEFAULT_SQ_DEADLINE
- default "none" if DEFAULT_SQ_NONE
-
-choice
- prompt "Default multi-queue blk-mq I/O scheduler"
- default DEFAULT_MQ_NONE
- help
- Select the I/O scheduler which will be used by default for blk-mq
- managed block devices with multiple queues.
-
- config DEFAULT_MQ_DEADLINE
- bool "MQ Deadline" if MQ_IOSCHED_DEADLINE=y
-
- config DEFAULT_MQ_NONE
- bool "None"
-
-endchoice
-
-config DEFAULT_MQ_IOSCHED
- string
- default "mq-deadline" if DEFAULT_MQ_DEADLINE
- default "none" if DEFAULT_MQ_NONE
-
endmenu
endif
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 9e8d679..c14f923 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -498,15 +498,6 @@ int blk_mq_sched_init(struct request_queue *q)
{
int ret;
-#if defined(CONFIG_DEFAULT_SQ_NONE)
- if (q->nr_hw_queues == 1)
- return 0;
-#endif
-#if defined(CONFIG_DEFAULT_MQ_NONE)
- if (q->nr_hw_queues > 1)
- return 0;
-#endif
-
mutex_lock(&q->sysfs_lock);
ret = elevator_init(q, NULL);
mutex_unlock(&q->sysfs_lock);
diff --git a/block/elevator.c b/block/elevator.c
index 699d10f..ac1c9f4 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -220,17 +220,24 @@ int elevator_init(struct request_queue *q, char *name)
}
if (!e) {
- if (q->mq_ops && q->nr_hw_queues == 1)
- e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false);
- else if (q->mq_ops)
- e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false);
- else
+ /*
+ * For blk-mq devices, we default to using mq-deadline,
+ * if available, for single queue devices. If deadline
+ * isn't available OR we have multiple queues, default
+ * to "none".
+ */
+ if (q->mq_ops) {
+ if (q->nr_hw_queues == 1)
+ e = elevator_get("mq-deadline", false);
+ if (!e)
+ return 0;
+ } else
e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
if (!e) {
printk(KERN_ERR
"Default I/O scheduler not found. " \
- "Using noop/none.\n");
+ "Using noop.\n");
e = elevator_get("noop", false);
}
}