Currently we don't limit O_DIRECT writes at all, we just let them queue
up as many as possible. As max priority writes should be able to get
full bandwidth, handle O_DIRECT writes just like we would high priority
buffered writes.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 8e20a0677dcf..9b17161b5668 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -450,6 +450,12 @@ static bool close_io(struct rq_wb *rwb)
time_before(now, rwb->last_comp + HZ / 10);
}
+static bool is_odirect_write(unsigned long rw)
+{
+ return op_is_write(rw) &&
+ ((rw & (REQ_SYNC | REQ_IDLE)) == (REQ_SYNC | REQ_IDLE));
+}
+
#define REQ_HIPRIO (REQ_SYNC | REQ_META | REQ_PRIO)
static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
@@ -474,7 +480,8 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
* the idle limit, or go to normal if we haven't had competing
* IO for a bit.
*/
- if ((rw & REQ_HIPRIO) || wb_recent_wait(rwb) || current_is_kswapd())
+ if ((rw & REQ_HIPRIO) || wb_recent_wait(rwb) || current_is_kswapd() ||
+ is_odirect_write(rw))
limit = rwb->rq_depth.max_depth;
else if ((rw & REQ_BACKGROUND) || close_io(rwb)) {
/*
@@ -578,12 +585,6 @@ static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
{
switch (bio_op(bio)) {
case REQ_OP_WRITE:
- /*
- * Don't throttle WRITE_ODIRECT
- */
- if ((bio->bi_opf & (REQ_SYNC | REQ_IDLE)) ==
- (REQ_SYNC | REQ_IDLE))
- return false;
/* fallthrough */
case REQ_OP_DISCARD:
return true;
--
Jens Axboe
