Commit bb926e80 authored by Jim Harris's avatar Jim Harris Committed by Konrad Sztyber
Browse files

nvmf: make poll groups count unassociated qpairs 



We make decisions on how to pick a poll group for a new
qpair by looking at each poll group's current_io_qpairs
count.  But this count isn't always accurate since it
doesn't get updated until after the CONNECT has
been received.

This means that if we accept a bunch of connections
all at once, they may all get assigned the same poll
group, because the target poll groups counter doesn't
get immediately incremented.

So add a new counter, current_unassociated_qpairs,
to account for these qpairs.  We protect this counter
with a lock, since the accept thread will increment
the counter, and the poll group thread will
decrement it when the qpair receives the CONNECT
allowing us to associated with a subsystem/controller..

If the qpair gets destroyed before the CONNECT is
received, we can use the qpair->connect_received
flag to decrement current_unassociated_qpairs.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I8bba8da2abfe225b3b9f981cd71b6f49e2b87391
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15693


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
parent f3e197ff

include/spdk/nvmf_transport.h

+8 −0
Original line number Diff line number Diff line
@@ -157,6 +157,12 @@ struct spdk_nvmf_poll_group { 
	struct spdk_nvmf_subsystem_poll_group		*sgroups;

	uint32_t					num_sgroups;



	/* Protected by mutex. Counts qpairs that have connected at a

	 * transport level, but are not associated with a subsystem

	 * or controller yet (because the CONNECT capsule hasn't

	 * been received). */

	uint32_t					current_unassociated_qpairs;



	/* All of the queue pairs that belong to this poll group */

	TAILQ_HEAD(, spdk_nvmf_qpair)			qpairs;
@@ -167,6 +173,8 @@ struct spdk_nvmf_poll_group { 
	void						*destroy_cb_arg;



	TAILQ_ENTRY(spdk_nvmf_poll_group)		link;



	pthread_mutex_t					mutex;

};



struct spdk_nvmf_listener {

lib/nvmf/ctrlr.c

+4 −0
Original line number Diff line number Diff line
@@ -729,6 +729,10 @@ _nvmf_ctrlr_connect(struct spdk_nvmf_request *req) 
	qpair->qid = cmd->qid;

	qpair->connect_received = true;



	pthread_mutex_lock(&qpair->group->mutex);

	qpair->group->current_unassociated_qpairs--;

	pthread_mutex_unlock(&qpair->group->mutex);



	if (0 == qpair->qid) {

		qpair->group->stat.admin_qpairs++;

		qpair->group->stat.current_admin_qpairs++;

lib/nvmf/nvmf.c

+9 −0
Original line number Diff line number Diff line
@@ -175,6 +175,7 @@ nvmf_tgt_create_poll_group(void *io_device, void *ctx_buf) 
	TAILQ_INIT(&group->tgroups);

	TAILQ_INIT(&group->qpairs);

	group->thread = thread;

	pthread_mutex_init(&group->mutex, NULL);



	group->poller = SPDK_POLLER_REGISTER(nvmf_poll_group_poll, group, 0);
@@ -887,6 +888,10 @@ spdk_nvmf_tgt_new_qpair(struct spdk_nvmf_tgt *tgt, struct spdk_nvmf_qpair *qpair 
	ctx->qpair = qpair;

	ctx->group = group;



	pthread_mutex_lock(&group->mutex);

	group->current_unassociated_qpairs++;

	pthread_mutex_unlock(&group->mutex);



	spdk_thread_send_msg(group->thread, _nvmf_poll_group_add, ctx);

}
@@ -1054,6 +1059,10 @@ _nvmf_qpair_destroy(void *ctx, int status) 
			assert(qpair->group->stat.current_io_qpairs > 0);

			qpair->group->stat.current_io_qpairs--;

		}

	} else {

		pthread_mutex_lock(&qpair->group->mutex);

		qpair->group->current_unassociated_qpairs--;

		pthread_mutex_unlock(&qpair->group->mutex);

	}



	if (ctrlr) {