Commit 5443e0ae authored by Jim Harris's avatar Jim Harris Committed by Ben Walker
Browse files

bdev: count down for qos tracking 



This will simplify some future patches which will
account for missed timeslice timers by allowing
additional IO/BW in the following timeslice.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I9dd46a768c98ce267c733a9f9719a2d3d2c3c915

Reviewed-on: https://review.gerrithub.io/423579


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarGangCao <gang.cao@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent 5595a7ca

lib/bdev/bdev.c

+25 −20
Original line number Diff line number Diff line
@@ -140,11 +140,15 @@ struct spdk_bdev_qos { 
	 *  only valid for the master channel which manages the outstanding IOs. */

	uint64_t max_byte_per_timeslice;



	/** Submitted IO in one timeslice (e.g., 1ms) */

	uint64_t io_submitted_this_timeslice;

	/** Remaining IO allowed in current timeslice (e.g., 1ms) */

	uint64_t io_remaining_this_timeslice;



	/** Submitted byte in one timeslice (e.g., 1ms) */

	uint64_t byte_submitted_this_timeslice;

	/** Remaining bytes allowed in current timeslice (e.g., 1ms).

	 *  Allowed to run negative if an I/O is submitted when some bytes are remaining,

	 *  but the I/O is bigger than that amount.  The excess will be deducted from the

	 *  next timeslice.

	 */

	int64_t byte_remaining_this_timeslice;



	/** Poller that processes queued I/O commands each time slice. */

	struct spdk_poller *poller;
@@ -1026,20 +1030,18 @@ _spdk_bdev_qos_io_submit(struct spdk_bdev_channel *ch) 
	struct spdk_bdev_shared_resource *shared_resource = ch->shared_resource;



	while (!TAILQ_EMPTY(&qos->queued)) {

		if (qos->max_ios_per_timeslice > 0 &&

		    qos->io_submitted_this_timeslice >= qos->max_ios_per_timeslice) {

		if (qos->max_ios_per_timeslice > 0 && qos->io_remaining_this_timeslice == 0) {

			break;

		}



		if (qos->max_byte_per_timeslice > 0 &&

		    qos->byte_submitted_this_timeslice >= qos->max_byte_per_timeslice) {

		if (qos->max_byte_per_timeslice > 0 && qos->byte_remaining_this_timeslice <= 0) {

			break;

		}



		bdev_io = TAILQ_FIRST(&qos->queued);

		TAILQ_REMOVE(&qos->queued, bdev_io, internal.link);

		qos->io_submitted_this_timeslice++;

		qos->byte_submitted_this_timeslice += _spdk_bdev_get_io_size_in_byte(bdev_io);

		qos->io_remaining_this_timeslice--;

		qos->byte_remaining_this_timeslice -= _spdk_bdev_get_io_size_in_byte(bdev_io);

		ch->io_outstanding++;

		shared_resource->io_outstanding++;

		bdev->fn_table->submit_request(ch->channel, bdev_io);
@@ -1434,14 +1436,17 @@ spdk_bdev_channel_poll_qos(void *arg) 
	struct spdk_bdev_qos *qos = arg;



	/* Reset for next round of rate limiting */

	qos->io_submitted_this_timeslice = 0;

	qos->io_remaining_this_timeslice = qos->max_ios_per_timeslice;



	/* More bytes sent in the last timeslice, allow less in this timeslice */

	if (qos->byte_submitted_this_timeslice > qos->max_byte_per_timeslice) {

		qos->byte_submitted_this_timeslice -= qos->max_byte_per_timeslice;

	} else {

		qos->byte_submitted_this_timeslice = 0;

	/* We may have allowed the bytes to slightly overrun in the last timeslice.

	 * byte_remaining_this_timeslice is signed, so if it's negative here, we'll

	 * account for the overrun so that the next timeslice will be appropriately

	 * reduced.

	 */

	if (qos->byte_remaining_this_timeslice > 0) {

		qos->byte_remaining_this_timeslice = 0;

	}

	qos->byte_remaining_this_timeslice += qos->max_byte_per_timeslice;



	_spdk_bdev_qos_io_submit(qos->ch);
@@ -1501,8 +1506,8 @@ _spdk_bdev_enable_qos(struct spdk_bdev *bdev, struct spdk_bdev_channel *ch) 


			TAILQ_INIT(&qos->queued);

			spdk_bdev_qos_update_max_quota_per_timeslice(qos);

			qos->io_submitted_this_timeslice = 0;

			qos->byte_submitted_this_timeslice = 0;

			qos->io_remaining_this_timeslice = qos->max_ios_per_timeslice;

			qos->byte_remaining_this_timeslice = qos->max_byte_per_timeslice;



			qos->poller = spdk_poller_register(spdk_bdev_channel_poll_qos,

							   qos,
@@ -1685,8 +1690,8 @@ spdk_bdev_qos_destroy(struct spdk_bdev *bdev) 
	new_qos->thread = NULL;

	new_qos->max_ios_per_timeslice = 0;

	new_qos->max_byte_per_timeslice = 0;

	new_qos->io_submitted_this_timeslice = 0;

	new_qos->byte_submitted_this_timeslice = 0;

	new_qos->io_remaining_this_timeslice = 0;

	new_qos->byte_remaining_this_timeslice = 0;

	new_qos->poller = NULL;

	TAILQ_INIT(&new_qos->queued);