Commit 27c6d380 authored by Jim Harris's avatar Jim Harris
Browse files

examples/nvme/perf: add a latency summary 



A single -L can be used to get the latency summary.
Two -L's (or -LL) can be used to get both the latency
summary and the detailed histogram.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I3fc0f4e2dfff7b041a665fe35aa33f11e4c3ebad
Reviewed-on: https://review.gerrithub.io/362270


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 32120b63

examples/nvme/perf/perf.c

+55 −2
Original line number Diff line number Diff line
@@ -116,6 +116,22 @@ struct ns_entry { 
#define BUCKET_MASK (NUM_BUCKETS_PER_RANGE - 1)

#define NUM_BUCKET_RANGES (BUCKET_LSB + 1)



static const double g_latency_cutoffs[] = {

	0.01,

	0.10,

	0.25,

	0.50,

	0.75,

	0.90,

	0.95,

	0.99,

	0.999,

	0.9999,

	0.99999,

	0.999999,

	-1,

};



struct ns_worker_ctx {

	struct ns_entry		*entry;

	uint64_t		io_completed;
@@ -753,6 +769,7 @@ static void usage(char *program_name) 
	printf("\t\t(read, write, randread, randwrite, rw, randrw)]\n");

	printf("\t[-M rwmixread (100 for reads, 0 for writes)]\n");

	printf("\t[-L enable latency tracking via sw, default: disabled]\n");

	printf("\t\t-L for latency summary, -LL for detailed histogram\n");

	printf("\t[-l enable latency tracking via ssd (if supported), default: disabled]\n");

	printf("\t[-t time in seconds]\n");

	printf("\t[-c core mask for I/O submission/completion.]\n");
@@ -833,6 +850,42 @@ print_performance(void) 
	if (g_latency_sw_tracking_level == 0) {

		return;

	}



	worker = g_workers;

	while (worker) {

		ns_ctx = worker->ns_ctx;

		while (ns_ctx) {

			uint64_t i, j, so_far = 0;

			double so_far_pct = 0, bucket = 0;

			const double *cutoff = g_latency_cutoffs;



			printf("Summary latency data for %-43.43s from core %u:\n", ns_ctx->entry->name, worker->lcore);

			printf("=================================================================================\n");



			for (i = 0; i < NUM_BUCKET_RANGES; i++) {

				for (j = 0; j < NUM_BUCKETS_PER_RANGE; j++) {

					so_far += ns_ctx->bucket[i][j];

					so_far_pct = (double)so_far / total_io_completed;

					bucket = get_us_from_bucket(i, j);

					if (ns_ctx->bucket[i][j] == 0) {

						continue;

					}

					while (so_far_pct >= *cutoff && *cutoff > 0) {

						printf("%8.4f%% : %9.3fus\n", *cutoff * 100, bucket);

						cutoff++;

					}

				}

			}

			printf("\n");

			ns_ctx = ns_ctx->next;

		}

		worker = worker->next;

	}



	if (g_latency_sw_tracking_level == 1) {

		return;

	}



	worker = g_workers;

	while (worker) {

		ns_ctx = worker->ns_ctx;
@@ -841,8 +894,8 @@ print_performance(void) 
			float so_far_pct = 0;

			double last_bucket, bucket = 0;



			printf("Latency data for %-43.43s from core %u:\n", ns_ctx->entry->name, worker->lcore);

			printf("=========================================================================\n");

			printf("Latency histogram for %-43.43s from core %u:\n", ns_ctx->entry->name, worker->lcore);

			printf("==============================================================================\n");

			printf("       Range in us     Cumulative    IO count\n");



			for (i = 0; i < NUM_BUCKET_RANGES; i++) {

test/lib/nvme/nvme.sh

+1 −1
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ done 
timing_exit identify



timing_enter perf

$rootdir/examples/nvme/perf/perf -q 128 -w read -s 12288 -t 1 -L

$rootdir/examples/nvme/perf/perf -q 128 -w read -s 12288 -t 1 -LL

timing_exit perf



timing_enter reserve