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authorYu Kuai <yukuai3@huawei.com>2022-10-19 20:15:18 +0800
committerJens Axboe <axboe@kernel.dk>2022-10-23 18:59:17 -0600
commit671fae5e51297fc76b3758ca2edd514858734a6a (patch)
treea7f429a319b75d06d43e3d4d757e2f2f664fbceb
parent181d06637451b5348d746039478e71fa53dfbff6 (diff)
blk-wbt: don't enable throttling if default elevator is bfq
Commit b5dc5d4d1f4f ("block,bfq: Disable writeback throttling") tries to disable wbt for bfq, it's done by calling wbt_disable_default() in bfq_init_queue(). However, wbt is still enabled if default elevator is bfq: device_add_disk elevator_init_mq bfq_init_queue wbt_disable_default -> done nothing blk_register_queue wbt_enable_default -> wbt is enabled Fix the problem by adding a new flag ELEVATOR_FLAG_DISBALE_WBT, bfq will set the flag in bfq_init_queue, and following wbt_enable_default() won't enable wbt while the flag is set. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221019121518.3865235-7-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/bfq-iosched.c2
-rw-r--r--block/blk-wbt.c11
-rw-r--r--block/elevator.h3
3 files changed, 12 insertions, 4 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 7ea427817f7f..ccfadc6f71bf 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7045,6 +7045,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
#endif
blk_stat_disable_accounting(bfqd->queue);
+ clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
wbt_enable_default(bfqd->queue);
kfree(bfqd);
@@ -7190,6 +7191,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
/* We dispatch from request queue wide instead of hw queue */
blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
+ set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
wbt_disable_default(q);
blk_stat_enable_accounting(q);
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 07ed0b0aee1f..68a774d7a7c9 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -27,6 +27,7 @@
#include "blk-wbt.h"
#include "blk-rq-qos.h"
+#include "elevator.h"
#define CREATE_TRACE_POINTS
#include <trace/events/wbt.h>
@@ -651,11 +652,15 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
*/
void wbt_enable_default(struct request_queue *q)
{
- struct rq_qos *rqos = wbt_rq_qos(q);
+ struct rq_qos *rqos;
+ bool disable_flag = q->elevator &&
+ test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
/* Throttling already enabled? */
+ rqos = wbt_rq_qos(q);
if (rqos) {
- if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
+ if (!disable_flag &&
+ RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
return;
}
@@ -664,7 +669,7 @@ void wbt_enable_default(struct request_queue *q)
if (!blk_queue_registered(q))
return;
- if (queue_is_mq(q))
+ if (queue_is_mq(q) && !disable_flag)
wbt_init(q);
}
EXPORT_SYMBOL_GPL(wbt_enable_default);
diff --git a/block/elevator.h b/block/elevator.h
index ed574bf3e629..75382471222d 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -104,7 +104,8 @@ struct elevator_queue
DECLARE_HASHTABLE(hash, ELV_HASH_BITS);
};
-#define ELEVATOR_FLAG_REGISTERED 0
+#define ELEVATOR_FLAG_REGISTERED 0
+#define ELEVATOR_FLAG_DISABLE_WBT 1
/*
* block elevator interface