Commit 2f500a23 authored by Richael Zhuang's avatar Richael Zhuang Committed by Jim Harris
Browse files

bdev/nvme: support switch to another io path after a number of IOs 



Support to specify rr_min_io for multipath round-robin policy,
which makes I/O switches to another io path after rr_min_io I/Os are
rounted to current io path.

Change-Id: I09f0d8d24271c0178ff816fa63ce8576b6e8ae47
Signed-off-by: default avatarRichael Zhuang <richael.zhuang@arm.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15445


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
parent 6fa3497b

CHANGELOG.md

+4 −0
Original line number Diff line number Diff line
@@ -94,6 +94,10 @@ Changed `bdev_raid_get_bdevs` RPC output format to include raid_bdev details. 
Added `selector` parameter to bdev_nvme_set_multipath_policy RPC to set path selector for multipath.

Option `round_robin` and `queue_depth` are available.



Added `rr_min_io` option to RPC bdev_nvme_set_multipath_policy. It switches I/O to

another path after rr_min_io I/Os are routed to current io path for the round-robin

path selector.



### bdevperf



Promoted the application to example to match similar programs: fio_plugin and perf.

doc/jsonrpc.md

+1 −0
Original line number Diff line number Diff line
@@ -4145,6 +4145,7 @@ Name | Optional | Type | Description 
name                    | Required | string      | Name of the NVMe bdev

policy                  | Required | string      | Multipath policy: active_active or active_passive

selector                | Optional | string      | Multipath selector: round_robin or queue_depth, used in active-active mode. Default is round_robin

rr_min_io               | Optional | number      | Number of I/Os routed to current io path before switching to another for round-robin selector. The min value is 1.



#### Example

module/bdev/nvme/bdev_nvme.c

+30 −6
Original line number Diff line number Diff line
@@ -557,6 +557,7 @@ static void 
bdev_nvme_clear_current_io_path(struct nvme_bdev_channel *nbdev_ch)

{

	nbdev_ch->current_io_path = NULL;

	nbdev_ch->rr_counter = 0;

}



static struct nvme_io_path *
@@ -662,6 +663,7 @@ bdev_nvme_create_bdev_channel_cb(void *io_device, void *ctx_buf) 


	nbdev_ch->mp_policy = nbdev->mp_policy;

	nbdev_ch->mp_selector = nbdev->mp_selector;

	nbdev_ch->rr_min_io = nbdev->rr_min_io;



	TAILQ_FOREACH(nvme_ns, &nbdev->nvme_ns_list, tailq) {

		rc = _bdev_nvme_add_io_path(nbdev_ch, nvme_ns);
@@ -928,9 +930,15 @@ _bdev_nvme_find_io_path_min_qd(struct nvme_bdev_channel *nbdev_ch) 
static inline struct nvme_io_path *

bdev_nvme_find_io_path(struct nvme_bdev_channel *nbdev_ch)

{

	if (spdk_likely(nbdev_ch->current_io_path != NULL &&

			nbdev_ch->mp_policy == BDEV_NVME_MP_POLICY_ACTIVE_PASSIVE)) {

	if (spdk_likely(nbdev_ch->current_io_path != NULL)) {

		if (nbdev_ch->mp_policy == BDEV_NVME_MP_POLICY_ACTIVE_PASSIVE) {

			return nbdev_ch->current_io_path;

		} else if (nbdev_ch->mp_selector == BDEV_NVME_MP_SELECTOR_ROUND_ROBIN) {

			if (++nbdev_ch->rr_counter < nbdev_ch->rr_min_io) {

				return nbdev_ch->current_io_path;

			}

			nbdev_ch->rr_counter = 0;

		}

	}



	if (nbdev_ch->mp_policy == BDEV_NVME_MP_POLICY_ACTIVE_PASSIVE ||
@@ -3359,6 +3367,7 @@ nvme_bdev_create(struct nvme_ctrlr *nvme_ctrlr, struct nvme_ns *nvme_ns) 
	bdev->ref = 1;

	bdev->mp_policy = BDEV_NVME_MP_POLICY_ACTIVE_PASSIVE;

	bdev->mp_selector = BDEV_NVME_MP_SELECTOR_ROUND_ROBIN;

	bdev->rr_min_io = UINT32_MAX;

	TAILQ_INIT(&bdev->nvme_ns_list);

	TAILQ_INSERT_TAIL(&bdev->nvme_ns_list, nvme_ns, tailq);

	bdev->opal = nvme_ctrlr->opal_dev != NULL;
@@ -4169,6 +4178,7 @@ _bdev_nvme_set_multipath_policy(struct spdk_io_channel_iter *i) 


	nbdev_ch->mp_policy = nbdev->mp_policy;

	nbdev_ch->mp_selector = nbdev->mp_selector;

	nbdev_ch->rr_min_io = nbdev->rr_min_io;

	bdev_nvme_clear_current_io_path(nbdev_ch);



	spdk_for_each_channel_continue(i, 0);
@@ -4176,7 +4186,8 @@ _bdev_nvme_set_multipath_policy(struct spdk_io_channel_iter *i) 


void

bdev_nvme_set_multipath_policy(const char *name, enum bdev_nvme_multipath_policy policy,

			       enum bdev_nvme_multipath_selector selector, bdev_nvme_set_multipath_policy_cb cb_fn, void *cb_arg)

			       enum bdev_nvme_multipath_selector selector, uint32_t rr_min_io,

			       bdev_nvme_set_multipath_policy_cb cb_fn, void *cb_arg)

{

	struct bdev_nvme_set_multipath_policy_ctx *ctx;

	struct spdk_bdev *bdev;
@@ -4185,11 +4196,23 @@ bdev_nvme_set_multipath_policy(const char *name, enum bdev_nvme_multipath_policy 


	assert(cb_fn != NULL);



	if (policy == BDEV_NVME_MP_POLICY_ACTIVE_ACTIVE && selector == BDEV_NVME_MP_SELECTOR_ROUND_ROBIN) {

		if (rr_min_io == UINT32_MAX) {

			rr_min_io = 1;

		} else if (rr_min_io == 0) {

			rc = -EINVAL;

			goto exit;

		}

	} else if (rr_min_io != UINT32_MAX) {

		rc = -EINVAL;

		goto exit;

	}



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

	if (ctx == NULL) {

		SPDK_ERRLOG("Failed to alloc context.\n");

		rc = -ENOMEM;

		goto err_alloc;

		goto exit;

	}



	ctx->cb_fn = cb_fn;
@@ -4213,6 +4236,7 @@ bdev_nvme_set_multipath_policy(const char *name, enum bdev_nvme_multipath_policy 
	pthread_mutex_lock(&nbdev->mutex);

	nbdev->mp_policy = policy;

	nbdev->mp_selector = selector;

	nbdev->rr_min_io = rr_min_io;

	pthread_mutex_unlock(&nbdev->mutex);



	spdk_for_each_channel(nbdev,
@@ -4225,7 +4249,7 @@ err_module: 
	spdk_bdev_close(ctx->desc);

err_open:

	free(ctx);

err_alloc:

exit:

	cb_fn(cb_arg, rc);

}

module/bdev/nvme/bdev_nvme.h

+5 −0
Original line number Diff line number Diff line
@@ -164,6 +164,7 @@ struct nvme_bdev { 
	int				ref;

	enum bdev_nvme_multipath_policy	mp_policy;

	enum bdev_nvme_multipath_selector mp_selector;

	uint32_t			rr_min_io;

	TAILQ_HEAD(, nvme_ns)		nvme_ns_list;

	bool				opal;

	TAILQ_ENTRY(nvme_bdev)		tailq;
@@ -203,6 +204,8 @@ struct nvme_bdev_channel { 
	struct nvme_io_path			*current_io_path;

	enum bdev_nvme_multipath_policy		mp_policy;

	enum bdev_nvme_multipath_selector	mp_selector;

	uint32_t				rr_min_io;

	uint32_t				rr_counter;

	STAILQ_HEAD(, nvme_io_path)		io_path_list;

	TAILQ_HEAD(retry_io_head, spdk_bdev_io)	retry_io_list;

	struct spdk_poller			*retry_io_poller;
@@ -353,11 +356,13 @@ typedef void (*bdev_nvme_set_multipath_policy_cb)(void *cb_arg, int rc); 
 * \param name NVMe bdev name

 * \param policy Multipath policy (active-passive or active-active)

 * \param selector Multipath selector (round_robin, queue_depth)

 * \param rr_min_io Number of IO to route to a path before switching to another for round-robin

 * \param cb_fn Function to be called back after completion.

 */

void bdev_nvme_set_multipath_policy(const char *name,

				    enum bdev_nvme_multipath_policy policy,

				    enum bdev_nvme_multipath_selector selector,

				    uint32_t rr_min_io,

				    bdev_nvme_set_multipath_policy_cb cb_fn,

				    void *cb_arg);

module/bdev/nvme/bdev_nvme_rpc.c

+5 −0
Original line number Diff line number Diff line
@@ -2210,6 +2210,7 @@ struct rpc_set_multipath_policy { 
	char *name;

	enum bdev_nvme_multipath_policy policy;

	enum bdev_nvme_multipath_selector selector;

	uint32_t rr_min_io;

};



static void
@@ -2256,6 +2257,7 @@ static const struct spdk_json_object_decoder rpc_set_multipath_policy_decoders[] 
	{"name", offsetof(struct rpc_set_multipath_policy, name), spdk_json_decode_string},

	{"policy", offsetof(struct rpc_set_multipath_policy, policy), rpc_decode_mp_policy},

	{"selector", offsetof(struct rpc_set_multipath_policy, selector), rpc_decode_mp_selector, true},

	{"rr_min_io", offsetof(struct rpc_set_multipath_policy, rr_min_io), spdk_json_decode_uint32, true},

};



struct rpc_set_multipath_policy_ctx {
@@ -2290,6 +2292,8 @@ rpc_bdev_nvme_set_multipath_policy(struct spdk_jsonrpc_request *request, 
		return;

	}



	ctx->req.rr_min_io = UINT32_MAX;



	if (spdk_json_decode_object(params, rpc_set_multipath_policy_decoders,

				    SPDK_COUNTOF(rpc_set_multipath_policy_decoders),

				    &ctx->req)) {
@@ -2309,6 +2313,7 @@ rpc_bdev_nvme_set_multipath_policy(struct spdk_jsonrpc_request *request, 
	}



	bdev_nvme_set_multipath_policy(ctx->req.name, ctx->req.policy, ctx->req.selector,

				       ctx->req.rr_min_io,

				       rpc_bdev_nvme_set_multipath_policy_done, ctx);

	return;