lkml.org 
[lkml]   [2022]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 4/5] blk-wbt: don't enable throttling if default elevator is bfq
Date
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>
---
block/bfq-iosched.c | 2 ++
block/blk-wbt.c | 8 +++++++-
block/elevator.h | 3 ++-
3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index fec52968fe07..f67ed271baa9 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7037,6 +7037,7 @@ static void bfq_exit_queue(struct elevator_queue *e)

#ifdef CONFIG_BFQ_GROUP_IOSCHED
blkcg_deactivate_policy(bfqd->queue, &blkcg_policy_bfq);
+ clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
wbt_enable_default(bfqd->queue);
#else
spin_lock_irq(&bfqd->lock);
@@ -7191,6 +7192,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);

#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
wbt_disable_default(q);
#endif
blk_stat_enable_accounting(q);
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 68851c2c02d2..279f8dc1e952 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>
@@ -645,9 +646,14 @@ 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;
+
+ if (q->elevator &&
+ test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
+ return;

/* Throttling already enabled? */
+ rqos = wbt_rq_qos(q);
if (rqos) {
if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
RQWB(rqos)->enable_state = WBT_STATE_ON_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
--
2.31.1
\
 
 \ /
  Last update: 2022-09-22 13:25    [W:0.086 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site