Commit b643dcd1 authored by Darek Stojaczyk's avatar Darek Stojaczyk Committed by Jim Harris
Browse files

vhost: introduce poll groups 



The goal is to remove legacy event messages from vhost.
The new message passing API accepts thread objects instead
of lcore numbers and poll groups are meant to simplify
the transition.

Eventually we'd like vhost to spawn its own threads and
do message passing only within those, but SPDK libraries
can't spawn their own threads just yet. As a stopgap, vhost
will now maintain a list of all available threads (in form
of "poll groups" to mimic nvmf) and will start pollers on
them using its own round robin scheduler.

This patch only adds the poll groups list, it doesn't
change any existing functionality.

Change-Id: I89cc5da5df3612827c6fc9015f03c94b5f4a10ad
Signed-off-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/452206


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 03b9841d

lib/vhost/vhost.c

+71 −27
Original line number Diff line number Diff line
@@ -43,6 +43,13 @@ 


#include "spdk_internal/memory.h"



struct vhost_poll_group {

	struct spdk_thread *thread;

	TAILQ_ENTRY(vhost_poll_group) tailq;

};



static TAILQ_HEAD(, vhost_poll_group) g_poll_groups = TAILQ_HEAD_INITIALIZER(g_poll_groups);



static uint32_t *g_num_ctrlrs;



/* Path to folder where character device will be created. Can be set by user. */
@@ -1433,6 +1440,58 @@ spdk_vhost_unlock(void) 
	pthread_mutex_unlock(&g_spdk_vhost_mutex);

}



static void

vhost_create_poll_group_done(void *ctx)

{

	spdk_vhost_init_cb init_cb = ctx;

	int ret;



	if (TAILQ_EMPTY(&g_poll_groups)) {

		/* No threads? Iteration failed? */

		init_cb(-ECHILD);

		return;

	}



	ret = spdk_vhost_scsi_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost controllers\n");

		goto out;

	}



	ret = spdk_vhost_blk_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost block controllers\n");

		goto out;

	}



#ifdef SPDK_CONFIG_VHOST_INTERNAL_LIB

	ret = spdk_vhost_nvme_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost NVMe controllers\n");

		goto out;

	}

#endif



out:

	init_cb(ret);

}



static void

vhost_create_poll_group(void *ctx)

{

	struct vhost_poll_group *pg;



	pg = calloc(1, sizeof(*pg));

	if (!pg) {

		SPDK_ERRLOG("Not enough memory to allocate poll groups\n");

		spdk_app_stop(-ENOMEM);

		return;

	}



	pg->thread = spdk_get_thread();

	TAILQ_INSERT_TAIL(&g_poll_groups, pg, tailq);

}



void

spdk_vhost_init(spdk_vhost_init_cb init_cb)

{
@@ -1444,7 +1503,7 @@ spdk_vhost_init(spdk_vhost_init_cb init_cb) 
		if (getcwd(dev_dirname, sizeof(dev_dirname) - 1) == NULL) {

			SPDK_ERRLOG("getcwd failed (%d): %s\n", errno, spdk_strerror(errno));

			ret = -1;

			goto out;

			goto err_out;

		}



		len = strlen(dev_dirname);
@@ -1460,34 +1519,14 @@ spdk_vhost_init(spdk_vhost_init_cb init_cb) 
		SPDK_ERRLOG("Could not allocate array size=%u for g_num_ctrlrs\n",

			    last_core + 1);

		ret = -1;

		goto out;

	}



	ret = spdk_vhost_scsi_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost controllers\n");

		ret = -1;

		goto out;

		goto err_out;

	}



	ret = spdk_vhost_blk_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost block controllers\n");

		ret = -1;

		goto out;

	}



#ifdef SPDK_CONFIG_VHOST_INTERNAL_LIB

	ret = spdk_vhost_nvme_controller_construct();

	if (ret != 0) {

		SPDK_ERRLOG("Cannot construct vhost NVMe controllers\n");

		ret = -1;

		goto out;

	}

#endif



	ret = 0;

out:

	spdk_for_each_thread(vhost_create_poll_group,

			     init_cb,

			     vhost_create_poll_group_done);

	return;

err_out:

	init_cb(ret);

}
@@ -1495,6 +1534,7 @@ static void 
_spdk_vhost_fini(void *arg1)

{

	struct spdk_vhost_dev *vdev, *tmp;

	struct vhost_poll_group *pg, *tpg;



	spdk_vhost_lock();

	vdev = spdk_vhost_dev_next(NULL);
@@ -1508,6 +1548,10 @@ _spdk_vhost_fini(void *arg1) 


	/* All devices are removed now. */

	free(g_num_ctrlrs);

	TAILQ_FOREACH_SAFE(pg, &g_poll_groups, tailq, tpg) {

		TAILQ_REMOVE(&g_poll_groups, pg, tailq);

		free(pg);

	}

	g_fini_cpl_cb();

}