Commit d9aed01f authored by Daniel Verkamp's avatar Daniel Verkamp
Browse files

nvme/fio_plugin: simplify getevents/event hooks 



The previous implementation tried to maintain a ring buffer of completed
I/O retrieved from ->getevents() that had not yet been retrieved by
->event(), but this is not necessary.  None of the other FIO engines
implement this sort of ring buffer, and the only code that calls
->getevents() will always retrieve the full number of events via
->event() afterwards.

Instead, just count how many I/Os have been completed within each
->getevents() call in iocq_count, and reset iocq_count on each new
->getevents().

Change-Id: I2776c3a5c89a0d2b24478328bc138ff7a9fb5bdd
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent b276649c

examples/nvme/fio_plugin/fio_plugin.c

+16 −25
Original line number Diff line number Diff line
@@ -77,9 +77,8 @@ struct spdk_fio_thread { 
	struct spdk_fio_ctrlr	*ctrlr_list;



	struct io_u		**iocq;	// io completion queue

	unsigned int		next_completion; // index where next completion will be placed

	unsigned int		getevents_start; // index where the next getevents call will start

	unsigned int		getevents_count; // The number of events in the current getevents window

	unsigned int		iocq_count;	// number of iocq entries filled by last getevents

	unsigned int		iocq_size;	// number of iocq entries allocated



};
@@ -186,7 +185,8 @@ static int spdk_fio_setup(struct thread_data *td) 
	td->io_ops_data = fio_thread;

	fio_thread->td = td;



	fio_thread->iocq = calloc(td->o.iodepth + 1, sizeof(struct io_u *));

	fio_thread->iocq_size = td->o.iodepth;

	fio_thread->iocq = calloc(fio_thread->iocq_size, sizeof(struct io_u *));

	assert(fio_thread->iocq != NULL);



	spdk_env_opts_init(&opts);
@@ -256,10 +256,8 @@ static void spdk_fio_completion_cb(void *ctx, const struct spdk_nvme_cpl *cpl) 
	struct spdk_fio_request		*fio_req = ctx;

	struct spdk_fio_thread		*fio_thread = fio_req->fio_thread;



	fio_thread->iocq[fio_thread->next_completion] = fio_req->io;

	if (++fio_thread->next_completion >= fio_thread->td->o.iodepth) {

		fio_thread->next_completion = 0;

	}

	assert(fio_thread->iocq_count < fio_thread->iocq_size);

	fio_thread->iocq[fio_thread->iocq_count++] = fio_req->io;

}



static int spdk_fio_queue(struct thread_data *td, struct io_u *io_u)
@@ -318,13 +316,10 @@ static int spdk_fio_queue(struct thread_data *td, struct io_u *io_u) 
static struct io_u *spdk_fio_event(struct thread_data *td, int event)

{

	struct spdk_fio_thread *fio_thread = td->io_ops_data;

	int idx = (fio_thread->getevents_start + event) % td->o.iodepth;



	if (event > (int)fio_thread->getevents_count) {

		return NULL;

	}



	return fio_thread->iocq[idx];

	assert(event >= 0);

	assert((unsigned)event < fio_thread->iocq_count);

	return fio_thread->iocq[event];

}



static int spdk_fio_getevents(struct thread_data *td, unsigned int min,
@@ -332,7 +327,6 @@ static int spdk_fio_getevents(struct thread_data *td, unsigned int min, 
{

	struct spdk_fio_thread *fio_thread = td->io_ops_data;

	struct spdk_fio_ctrlr *fio_ctrlr;

	unsigned int count = 0;

	struct timespec t0, t1;

	uint64_t timeout = 0;
@@ -341,19 +335,18 @@ static int spdk_fio_getevents(struct thread_data *td, unsigned int min, 
		clock_gettime(CLOCK_MONOTONIC_RAW, &t0);

	}



	fio_thread->getevents_start = (fio_thread->getevents_start + fio_thread->getevents_count) %

				      fio_thread->td->o.iodepth;

	fio_thread->iocq_count = 0;



	for (;;) {

		fio_ctrlr = fio_thread->ctrlr_list;

		while (fio_ctrlr != NULL) {

			count += spdk_nvme_qpair_process_completions(fio_ctrlr->qpair, max - count);

			fio_ctrlr = fio_ctrlr->next;

		}

			spdk_nvme_qpair_process_completions(fio_ctrlr->qpair, max - fio_thread->iocq_count);



			if (fio_thread->iocq_count >= min) {

				return fio_thread->iocq_count;

			}



		if (count >= min) {

			break;

			fio_ctrlr = fio_ctrlr->next;

		}



		if (t) {
@@ -366,9 +359,7 @@ static int spdk_fio_getevents(struct thread_data *td, unsigned int min, 
		}

	}



	fio_thread->getevents_count = count;



	return count;

	return fio_thread->iocq_count;

}



static int spdk_fio_invalidate(struct thread_data *td, struct fio_file *f)