Add nOS-V HWC rt tests

test/rt/nosv/CMakeLists.txt

@@ -24,7 +24,7 @@ function(nosv_test)
   cmake_parse_arguments(
     NOSV_TEST "${switches}" "${single}" "${multi}" ${ARGN})
   ovni_test(${ARGN})
-  target_link_libraries("${OVNI_TEST_NAME}" PRIVATE PkgConfig::NOSV)
+  target_link_libraries("${OVNI_TEST_NAME}" PRIVATE PkgConfig::NOSV m)
   set_property(TEST "${OVNI_TEST_NAME}" APPEND
     PROPERTY
       ENVIRONMENT "NOSV_CONFIG=${OVNI_TEST_SOURCE_DIR}/rt/nosv/nosv.toml")
@@ -65,6 +65,9 @@ nosv_test(several-tasks.c SORT NAME several-tasks-breakdown-level-2 LEVEL 2 BREA
 nosv_test(several-tasks.c SORT NAME several-tasks-breakdown-level-3 LEVEL 3 BREAKDOWN)
 nosv_test(several-tasks.c SORT NAME several-tasks-breakdown-level-4 LEVEL 4 BREAKDOWN)
 
+nosv_test(several-tasks.c NAME hwc-tasks DRIVER "hwc.driver.sh")
+nosv_test(hwc-stride.c DRIVER "hwc-stride.driver.sh")
+
 if (PERF_PARANOID_KERNEL)
   message(STATUS "Enabling perf paranoid tests for nOS-V")
   nosv_test(kernel.c NAME kernel-overflow DRIVER "kernel-overflow.driver.sh")

test/rt/nosv/hwc-stride.c

@@ -0,0 +1,117 @@
+/* Copyright (c) 2025 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+/*
+ * This test creates several tasks that all perform the computation with the
+ * same instructions. However, the access to the memory is done differently. The
+ * first set of tasks use a stride 1, the next 2, the next 4 and so on until
+ * 2^(NSTRIDE-1). This access causes more L3 cache misses, which increases the
+ * execution time, typically directly proportional to the stride number.
+ *
+ * The number of instructions given by PAPI_TOT_INS should remain constant
+ * across tasks, but it is expected that PAPI_L3_TCM increases with the
+ * stride.
+ */
+
+#include <math.h>
+#include <nosv.h>
+#include <stdatomic.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "compat.h"
+
+#define NTASKS 200
+atomic_int ncompleted = 0;
+
+nosv_task_t tasks[NTASKS];
+
+#define NRUNS 2
+#define NSTRIDE 4
+#define MAXN (256L * 1024L) /* Adjust this for larger L3 */
+
+struct meta {
+	long n;
+	long stride;
+	double *vec;
+};
+
+static double
+get_time(void)
+{
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return (double) ts.tv_sec + (double) ts.tv_nsec * 1.0e-9;
+}
+
+static void
+task_body(nosv_task_t task)
+{
+	struct meta *meta = nosv_get_task_metadata(task);
+
+	long stride = meta->stride;
+
+	/* Stride access, some computation */
+	for (long i = 0; i < stride; i++)
+		for (long j = i; j < meta->n; j += stride)
+			meta->vec[j] = sqrt(meta->vec[j]);
+
+	atomic_fetch_add(&ncompleted, 1);
+}
+
+int
+main(void)
+{
+	nosv_init();
+
+	nosv_task_type_t task_type;
+	nosv_type_init(&task_type, task_body, NULL, NULL, "task", NULL, NULL, 0);
+
+	for (int i = 0; i < NTASKS; i++) {
+		nosv_create(&tasks[i], task_type, sizeof(struct meta), 0);
+		struct meta *meta = nosv_get_task_metadata(tasks[i]);
+		meta->n = MAXN;
+		meta->vec = calloc(MAXN, sizeof(double));
+		for (long i = 0; i < MAXN; i++)
+			meta->vec[i] = (double) i;
+	}
+
+	fprintf(stderr, "%8s  %8s  %8s\n", "run", "stride", "time");
+
+	/* Repeat for warmup */
+	for (int run = 0; run < NRUNS; run++) {
+		for (int s = 0; s < NSTRIDE; s++) {
+			long stride = 1L << s;
+
+			atomic_store(&ncompleted, 0); /* reset */
+
+			double t0 = get_time();
+
+			for (int i = 0; i < NTASKS; i++) {
+				struct meta *meta = nosv_get_task_metadata(tasks[i]);
+				meta->stride = stride;
+				nosv_submit(tasks[i], 0);
+			}
+
+			while (atomic_load(&ncompleted) != NTASKS)
+				sleep_us(1000);
+
+			double t1 = get_time();
+
+			printf("%8d  %8ld  %8.3f\n", run, stride, t1 - t0);
+		}
+	}
+
+	for (int i = 0; i < NTASKS; i++) {
+		struct meta *meta = nosv_get_task_metadata(tasks[i]);
+		free(meta->vec);
+		nosv_destroy(tasks[i], 0);
+	}
+
+	nosv_type_destroy(task_type, 0);
+
+	nosv_shutdown();
+
+	return 0;
+}

test/rt/nosv/hwc-stride.driver.sh

@@ -0,0 +1,18 @@
+target=$OVNI_TEST_BIN
+
+# We will set our own
+unset NOSV_CONFIG
+unset NOSV_CONFIG_OVERRIDE
+
+export NOSV_APPID=1
+
+cat > nosv.toml << EOF
+instrumentation.version = "ovni"
+ovni.level = 2
+hwcounters.backend = "papi"
+hwcounters.papi_events = [ "PAPI_TOT_INS", "PAPI_TOT_CYC", "PAPI_L3_TCM" ]
+EOF
+
+$target
+
+ovniemu -l ovni

test/rt/nosv/hwc.driver.sh

@@ -0,0 +1,18 @@
+target=$OVNI_TEST_BIN
+
+# We will set our own
+unset NOSV_CONFIG
+unset NOSV_CONFIG_OVERRIDE
+
+export NOSV_APPID=1
+
+cat > nosv.toml << EOF
+instrumentation.version = "ovni"
+ovni.level = 2
+hwcounters.backend = "papi"
+hwcounters.papi_events = [ "PAPI_TOT_INS", "PAPI_TOT_CYC" ]
+EOF
+
+$target
+
+ovniemu -l ovni