Commit 7b89d460 authored by Zizhi Wo's avatar Zizhi Wo Committed by Jens Axboe
Browse files

blk-throttle: Delete unnecessary carryover-related fields from throtl_grp 



We no longer need carryover_[bytes/ios] in tg, so it is removed. The
related comments about carryover in tg are also merged into
[bytes/io]_disp, and modify other related comments.

Signed-off-by: default avatarZizhi Wo <wozizhi@huawei.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250417132054.2866409-3-wozizhi@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f66cf69e

block/blk-throttle.c

+4 −4
Original line number Diff line number Diff line
@@ -658,9 +658,9 @@ static void __tg_update_carryover(struct throtl_grp *tg, bool rw, 


	/*

	 * If config is updated while bios are still throttled, calculate and

	 * accumulate how many bytes/ios are waited across changes. And

	 * carryover_bytes/ios will be used to calculate new wait time under new

	 * configuration.

	 * accumulate how many bytes/ios are waited across changes. And use the

	 * calculated carryover (@bytes/@ios) to update [bytes/io]_disp, which

	 * will be used to calculate new wait time under new configuration.

	 */

	if (bps_limit != U64_MAX)

		*bytes = calculate_bytes_allowed(bps_limit, jiffy_elapsed) -
@@ -680,7 +680,7 @@ static void tg_update_carryover(struct throtl_grp *tg) 
	__tg_update_carryover(tg, READ, &bytes[READ], &ios[READ]);

	__tg_update_carryover(tg, WRITE, &bytes[WRITE], &ios[WRITE]);



	/* see comments in struct throtl_grp for meaning of these fields. */

	/* see comments in struct throtl_grp for meaning of carryover. */

	throtl_log(&tg->service_queue, "%s: %lld %lld %d %d\n", __func__,

		   bytes[READ], bytes[WRITE], ios[READ], ios[WRITE]);

}

block/blk-throttle.h

+8 −11
Original line number Diff line number Diff line
@@ -102,19 +102,16 @@ struct throtl_grp { 
	/* IOPS limits */

	unsigned int iops[2];



	/* Number of bytes dispatched in current slice */

	int64_t bytes_disp[2];

	/* Number of bio's dispatched in current slice */

	int io_disp[2];



	/*

	 * The following two fields are updated when new configuration is

	 * submitted while some bios are still throttled, they record how many

	 * bytes/ios are waited already in previous configuration, and they will

	 * be used to calculate wait time under new configuration.

	 * Number of bytes/bio's dispatched in current slice.

	 * When new configuration is submitted while some bios are still throttled,

	 * first calculate the carryover: the amount of bytes/IOs already waited

	 * under the previous configuration. Then, [bytes/io]_disp are represented

	 * as the negative of the carryover, and they will be used to calculate the

	 * wait time under the new configuration.

	 */

	long long carryover_bytes[2];

	int carryover_ios[2];

	int64_t bytes_disp[2];

	int io_disp[2];



	unsigned long last_check_time;