diff mbox series

[V2,4/7] blk-throttle: Introduce flag "BIO_TG_BPS_THROTTLED"

Message ID 20250417105833.1930283-5-wozizhi@huawei.com (mailing list archive)
State New
Headers show
Series blk-throttle: Split the blkthrotl queue to solve the IO delay issue | expand

Commit Message

Zizhi Wo April 17, 2025, 10:58 a.m. UTC 
Subsequent patches will split the single queue into separate bps and iops
queues. To prevent IO that has already passed through the bps queue at a
single tg level from being counted toward bps wait time again, we introduce
"BIO_TG_BPS_THROTTLED" flag. Since throttle and QoS operate at different
levels, we reuse the value as "BIO_QOS_THROTTLED".

We set this flag when charge bps and clear it when charge iops, as the bio
will move to the upper-level tg or be dispatched.

This patch does not involve functional changes.

Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
---
 block/blk-throttle.c      | 9 +++++++--
 include/linux/blk_types.h | 5 +++++
 2 files changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 91ee1c502b41..caae2e3b7534 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -741,12 +741,16 @@  static void throtl_charge_bps_bio(struct throtl_grp *tg, struct bio *bio)
 	unsigned int bio_size = throtl_bio_data_size(bio);
 
 	/* Charge the bio to the group */
-	if (!bio_flagged(bio, BIO_BPS_THROTTLED))
+	if (!bio_flagged(bio, BIO_BPS_THROTTLED) &&
+	    !bio_flagged(bio, BIO_TG_BPS_THROTTLED)) {
+		bio_set_flag(bio, BIO_TG_BPS_THROTTLED);
 		tg->bytes_disp[bio_data_dir(bio)] += bio_size;
+	}
 }
 
 static void throtl_charge_iops_bio(struct throtl_grp *tg, struct bio *bio)
 {
+	bio_clear_flag(bio, BIO_TG_BPS_THROTTLED);
 	tg->io_disp[bio_data_dir(bio)]++;
 }
 
@@ -772,7 +776,8 @@  static unsigned long tg_dispatch_bps_time(struct throtl_grp *tg, struct bio *bio
 
 	/* no need to throttle if this bio's bytes have been accounted */
 	if (bps_limit == U64_MAX || tg->flags & THROTL_TG_CANCELING ||
-	    bio_flagged(bio, BIO_BPS_THROTTLED))
+	    bio_flagged(bio, BIO_BPS_THROTTLED) ||
+	    bio_flagged(bio, BIO_TG_BPS_THROTTLED))
 		return 0;
 
 	tg_update_slice(tg, rw);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index dce7615c35e7..7e0eddfaaa98 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -296,6 +296,11 @@  enum {
 				 * of this bio. */
 	BIO_CGROUP_ACCT,	/* has been accounted to a cgroup */
 	BIO_QOS_THROTTLED,	/* bio went through rq_qos throttle path */
+	/*
+	 * This bio has undergone rate limiting at the single throtl_grp level bps
+	 * queue. Since throttle and QoS are not at the same level, reuse the value.
+	 */
+	BIO_TG_BPS_THROTTLED = BIO_QOS_THROTTLED,
 	BIO_QOS_MERGED,		/* but went through rq_qos merge path */
 	BIO_REMAPPED,
 	BIO_ZONE_WRITE_PLUGGING, /* bio handled through zone write plugging */