Commit f95bd3b6 authored by paul luse's avatar paul luse Committed by Jim Harris
Browse files

lib/idxd: change how we complete batch desc 



Previously we used a counter of our own to make sure all batch
elements plus the batch itself were done before we freed the batch.
This was due to some observations early on that the batch desc
could complete before the individual elements and a lack of clarity
as to whether this was due to the simulator or the fact that
we poll on completions and could therefore "see" completions in
a different order at that time (we were using bit arrays to poll).

Now we use an ordered (in time) list to poll locations so if we
instead put the elements on the list first and then the batch desc
itself we are assured to always "see" them in order provided the
underlying device meets spec which there's no reason to assume it
does not.

This simplifies things a bit at the same time and still assures
that we call list calbacks in order and then the batch callback
without "special" handling.

Signed-off-by: default avatarpaul luse <paul.e.luse@intel.com>
Change-Id: I4d9e3997786f2116ce6515682b8117799c645f51
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8397


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 91cab341

lib/idxd/idxd.c

+21 −23
Original line number Diff line number Diff line
@@ -646,7 +646,7 @@ spdk_idxd_batch_create(struct spdk_idxd_io_channel *chan) 


	if (!TAILQ_EMPTY(&chan->batch_pool)) {

		batch = TAILQ_FIRST(&chan->batch_pool);

		batch->index = batch->remaining = 0;

		batch->index = 0;

		TAILQ_REMOVE(&chan->batch_pool, batch, link);

		TAILQ_INSERT_TAIL(&chan->batches, batch, link);

	} else {
@@ -677,7 +677,6 @@ static void 
_free_batch(struct idxd_batch *batch, struct spdk_idxd_io_channel *chan)

{

	SPDK_DEBUGLOG(idxd, "Free batch %p\n", batch);

	assert(batch->remaining == 0);

	TAILQ_REMOVE(&chan->batches, batch, link);

	TAILQ_INSERT_TAIL(&chan->batch_pool, batch, link);

}
@@ -690,7 +689,7 @@ spdk_idxd_batch_cancel(struct spdk_idxd_io_channel *chan, struct idxd_batch *bat 
		return -EINVAL;

	}



	if (batch->remaining > 0) {

	if (batch->index > 0) {

		SPDK_ERRLOG("Cannot cancel batch, already submitted to HW.\n");

		return -EINVAL;

	}
@@ -723,40 +722,42 @@ spdk_idxd_batch_submit(struct spdk_idxd_io_channel *chan, struct idxd_batch *bat 
		}

	}



	/* Add the batch elements completion contexts to the outstanding list to be polled. */

	for (i = 0 ; i < batch->index; i++) {

		TAILQ_INSERT_TAIL(&chan->comp_ctx_oustanding, (struct idxd_comp *)&batch->user_completions[i],

				  link);

	}



	/* Common prep. */

	rc = _idxd_prep_command(chan, cb_fn, cb_arg, &desc, &comp);

	if (rc) {

		return rc;

		goto error;

	}



	rc = _vtophys(batch->user_desc, &desc_addr, batch->remaining * sizeof(struct idxd_hw_desc));

	rc = _vtophys(batch->user_desc, &desc_addr, batch->index * sizeof(struct idxd_hw_desc));

	if (rc) {

		return -EINVAL;

		rc = -EINVAL;

		goto error;

	}



	/* Command specific. */

	desc->opcode = IDXD_OPCODE_BATCH;

	desc->desc_list_addr = desc_addr;

	desc->desc_count = batch->remaining = batch->index;

	desc->desc_count = batch->index;

	comp->batch = batch;

	assert(batch->index <= DESC_PER_BATCH);



	/* Add the batch elements completion contexts to the outstanding list to be polled. */

	for (i = 0 ; i < batch->index; i++) {

		TAILQ_INSERT_TAIL(&chan->comp_ctx_oustanding, (struct idxd_comp *)&batch->user_completions[i],

				  link);

	}



	/* Add one for the batch desc itself, we use this to determine when

	 * to free the batch.

	 */

	batch->remaining++;



	/* Submit operation. */

	_submit_to_hw(chan, desc);

	SPDK_DEBUGLOG(idxd, "Submitted batch %p\n", batch);



	return 0;

error:

	for (i = 0 ; i < batch->index; i++) {

		comp = TAILQ_LAST(&chan->comp_ctx_oustanding, comp_head);

		TAILQ_REMOVE(&chan->comp_ctx_oustanding, comp, link);

	}

	return rc;

}



static int
@@ -1100,12 +1101,9 @@ spdk_idxd_process_events(struct spdk_idxd_io_channel *chan) 
				spdk_bit_array_clear(chan->ring_slots, comp_ctx->index);

			}



			if (comp_ctx->batch) {

				assert(comp_ctx->batch->remaining > 0);

				if (--comp_ctx->batch->remaining == 0) {

			if (comp_ctx->desc->opcode == IDXD_OPCODE_BATCH) {

				_free_batch(comp_ctx->batch, chan);

			}

			}

		} else {

			/*

			 * oldest locations are at the head of the list so if

lib/idxd/idxd.h

+11 −12
Original line number Diff line number Diff line
@@ -84,7 +84,6 @@ static inline void movdir64b(void *dst, const void *src) 
struct idxd_batch {

	struct idxd_hw_desc		*user_desc;

	struct idxd_comp		*user_completions;

	uint32_t			remaining;

	uint8_t				index;

	TAILQ_ENTRY(idxd_batch)		link;

};
@@ -114,7 +113,7 @@ struct spdk_idxd_io_channel { 
	struct idxd_comp			*completions;



	/* Current list of oustanding completion addresses to poll. */

	TAILQ_HEAD(, idxd_comp)		comp_ctx_oustanding;

	TAILQ_HEAD(comp_head, idxd_comp)	comp_ctx_oustanding;



	/*

	 * We use one bit array to track ring slots for both