Commit 0ee9e404 authored by Jim Harris's avatar Jim Harris Committed by Ben Walker
Browse files

bdev: keep a count of each channel's outstanding IO 



There are several possible usages of this information -
the first will be related to starting a poller for a bdev
channel when there are I/O that need to be retried.
Usually we can retry an I/O when a previous I/O completes,
but if there are no outstanding I/O, we need to start a
poller.  This count will help us make that decision.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Ifff7d99970510785a1cf30d20b86b3974ce8a106
Reviewed-on: https://review.gerrithub.io/362235


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 7a7593c0

lib/bdev/bdev.c

+17 −0
Original line number Diff line number Diff line
@@ -99,6 +99,12 @@ struct spdk_bdev_channel { 


	struct spdk_bdev_io_stat stat;



	/*

	 * Count of I/O submitted to bdev module and waiting for completion.

	 * Incremented before submit_request() is called on an spdk_bdev_io.

	 */

	uint64_t		io_outstanding;



#ifdef SPDK_CONFIG_VTUNE

	uint64_t		start_tsc;

	uint64_t		interval_tsc;
@@ -483,6 +489,7 @@ __submit_request(struct spdk_bdev *bdev, struct spdk_bdev_io *bdev_io) 


	ch = bdev_io->ch->channel;



	bdev_io->ch->io_outstanding++;

	bdev_io->in_submit_request = true;

	bdev->fn_table->submit_request(ch, bdev_io);

	bdev_io->in_submit_request = false;
@@ -509,6 +516,12 @@ spdk_bdev_io_resubmit(struct spdk_bdev_io *bdev_io, struct spdk_bdev *new_bdev) 
	 */

	bdev_io->gencnt = new_bdev->gencnt;



	/*

	 * This bdev_io was already submitted so decrement io_outstanding to ensure it

	 *  does not get double-counted.

	 */

	assert(bdev_io->ch->io_outstanding > 0);

	bdev_io->ch->io_outstanding--;

	__submit_request(new_bdev, bdev_io);

}
@@ -583,6 +596,7 @@ spdk_bdev_channel_create(void *io_device, void *ctx_buf) 
	ch->channel = bdev->fn_table->get_io_channel(bdev->ctxt);

	ch->mgmt_channel = spdk_get_io_channel(&g_bdev_mgr);

	memset(&ch->stat, 0, sizeof(ch->stat));

	ch->io_outstanding = 0;



#ifdef SPDK_CONFIG_VTUNE

	{
@@ -626,6 +640,7 @@ spdk_bdev_channel_destroy(void *io_device, void *ctx_buf) 
	_spdk_bdev_abort_io(&mgmt_channel->need_buf_small, ch);

	_spdk_bdev_abort_io(&mgmt_channel->need_buf_large, ch);



	assert(ch->io_outstanding == 0);

	spdk_put_io_channel(ch->channel);

	spdk_put_io_channel(ch->mgmt_channel);

}
@@ -1132,6 +1147,8 @@ spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status sta 
		return;

	}



	assert(bdev_io->ch->io_outstanding > 0);

	bdev_io->ch->io_outstanding--;

	if (bdev_io->type == SPDK_BDEV_IO_TYPE_RESET) {

		/* Successful reset */

		if (status == SPDK_BDEV_IO_STATUS_SUCCESS) {