Commit bb8102b1 authored by paul luse's avatar paul luse Committed by Jim Harris
Browse files

module/idxd: add lock around idxd device selection 



Without it multiple threads can race and end up sharing a device
when the intention is sharing only after full round robin.

Signed-off-by: default avatarpaul luse <paul.e.luse@intel.com>
Change-Id: I29b854ff837d56078bc033802d3df244728a29aa
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8187


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 3bbfbb5b

module/accel/idxd/accel_engine_idxd.c

+7 −2
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct idxd_device { 
static TAILQ_HEAD(, idxd_device) g_idxd_devices = TAILQ_HEAD_INITIALIZER(g_idxd_devices);

static struct idxd_device *g_next_dev = NULL;

static uint32_t g_num_devices = 0;

static pthread_mutex_t g_dev_lock = PTHREAD_MUTEX_INITIALIZER;



struct idxd_io_channel {

	struct spdk_idxd_io_channel	*chan;
@@ -82,6 +83,7 @@ static struct idxd_device * 
idxd_select_device(struct idxd_io_channel *chan)

{

	uint32_t count = 0;

	struct idxd_device *dev;



	/*

	 * We allow channels to share underlying devices,
@@ -90,20 +92,23 @@ idxd_select_device(struct idxd_io_channel *chan) 
	 */

	do {

		/* select next device */

		pthread_mutex_lock(&g_dev_lock);

		g_next_dev = TAILQ_NEXT(g_next_dev, tailq);

		if (g_next_dev == NULL) {

			g_next_dev = TAILQ_FIRST(&g_idxd_devices);

		}

		dev = g_next_dev;

		pthread_mutex_unlock(&g_dev_lock);



		/*

		 * Now see if a channel is available on this one. We only

		 * allow a specific number of channels to share a device

		 * to limit outstanding IO for flow control purposes.

		 */

		chan->chan = spdk_idxd_get_channel(g_next_dev->idxd);

		chan->chan = spdk_idxd_get_channel(dev->idxd);

		if (chan->chan != NULL) {

			chan->max_outstanding = spdk_idxd_chan_get_max_operations(chan->chan);

			return g_next_dev;

			return dev;

		}

	} while (count++ < g_num_devices);