Add passive and active tests for OpenMP

Makes sure that we are no longer generating too many pause events.

test/rt/openmp/CMakeLists.txt

@@ -1,4 +1,4 @@
-# Copyright (c) 2022-2024 Barcelona Supercomputing Center (BSC)
+# Copyright (c) 2022-2025 Barcelona Supercomputing Center (BSC)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 check_c_compiler_flag("-fopenmp=libompv" OPENMPV_COMPILER_FOUND)
@@ -37,6 +37,7 @@ function(openmp_rt_test)
     ENVIRONMENT "NOSV_CONFIG_OVERRIDE=instrumentation.version=ovni")
 endfunction()
 
+openmp_rt_test(active.c DRIVER active.driver.sh)
 openmp_rt_test(barrier-explicit.c)
 openmp_rt_test(critical.c)
 openmp_rt_test(if0-nested-task.c)
@@ -46,6 +47,7 @@ openmp_rt_test(parallel-for.c)
 openmp_rt_test(parallel-loop.c)
 openmp_rt_test(parallel-nested.c)
 openmp_rt_test(parallel-task.c)
+openmp_rt_test(passive.c DRIVER passive.driver.sh)
 openmp_rt_test(sections.c)
 openmp_rt_test(simple-task.c)
 openmp_rt_test(task.c)

test/rt/openmp/active.c

@@ -0,0 +1,19 @@
+#include "compat.h"
+
+/* This test tries to make threads generate as many nosv_pause() calls to try to
+ * flood the trace as possible. */
+
+int main(void)
+{
+	#pragma omp parallel
+	#pragma omp single nowait
+	{
+		#pragma omp task
+		{
+			sleep_us(10000);
+		}
+		sleep_us(10000);
+	}
+
+	return 0;
+}

test/rt/openmp/active.driver.sh

@@ -0,0 +1,24 @@
+target=$OVNI_TEST_BIN
+
+export NOSV_APPID=1
+export OMP_OVNI=1
+export OMP_WAIT_POLICY=active
+export OMP_NUM_THREADS=4
+export NOSV_CONFIG_OVERRIDE="instrumentation.version=ovni,ovni.level=3"
+
+# Repeat several times, as the test is not stable. We only want to be sure that
+# we never generate too many events.
+for i in $(seq 10); do
+  rm -rf ovni
+
+  $target
+
+  ovnisort ovni
+  # No need to emulate
+  #ovniemu -l ovni
+
+  # Make sure that we only see a low number of threads being paused
+  ovnitop ovni > top.txt
+  cat top.txt
+  awk -v n=500 '/^OHp/ && $2 > n { printf("too many OHp events: %d > %d", $2, n); exit 1 }' < top.txt
+done

test/rt/openmp/passive.c

@@ -0,0 +1,20 @@
+#include "compat.h"
+#include <omp.h>
+
+/* This test tries to make threads generate as many nosv_pause() calls to try to
+ * flood the trace as possible. This problem should be solved by the new passive
+ * mechanism. */
+
+int main(void)
+{
+	#pragma omp parallel
+	{
+		if (omp_get_thread_num() == 1)
+		#pragma omp task
+		{
+			sleep_us(10000);
+		}
+	}
+
+	return 0;
+}

test/rt/openmp/passive.driver.sh

@@ -0,0 +1,23 @@
+target=$OVNI_TEST_BIN
+
+export NOSV_APPID=1
+export OMP_OVNI=1
+export OMP_WAIT_POLICY=passive
+export OMP_NUM_THREADS=4
+export NOSV_CONFIG_OVERRIDE="instrumentation.version=ovni,ovni.level=2"
+
+# Repeat several times, as the test is not stable. We only want to be sure that
+# we never generate too many events.
+for i in $(seq 10); do
+  rm -rf ovni
+
+  $target
+
+  ovnisort ovni
+  ovniemu -l ovni
+
+  # Make sure that we only see a low number of threads being paused
+  ovnitop ovni > top.txt
+  cat top.txt
+  awk -v n=500 '/^OHp/ && $2 > n { printf("too many OHp events: %d > %d", $2, n); exit 1 }' < top.txt
+done