[DTrace-devel] [PATCH 4/4] test: -xcpu for just one CPU, loop over all CPUs in stress test (syscall)

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 test/stress/options/tst.cpu-syscall.sh   | 151 +++++++++++++++++++++++
 test/unittest/options/tst.cpu-syscall.sh |  37 +++---
 2 files changed, 172 insertions(+), 16 deletions(-)
 create mode 100755 test/stress/options/tst.cpu-syscall.sh

diff --git a/test/stress/options/tst.cpu-syscall.sh b/test/stress/options/tst.cpu-syscall.sh
new file mode 100755
index 00000000..e3b0c50e
--- /dev/null
+++ b/test/stress/options/tst.cpu-syscall.sh
@@ -0,0 +1,151 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+# Licensed under the Universal Permissive License v 1.0 as shown at
+# http://oss.oracle.com/licenses/upl.
+#
+
+dtrace=$1
+
+DIRNAME="$tmpdir/cpu-syscall.$$.$RANDOM"
+mkdir -p $DIRNAME
+cd $DIRNAME
+
+#
+# Make trigger code and compile it.
+#
+
+cat << EOF > main.c
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <errno.h>
+
+int ncpus;
+cpu_set_t *mask;
+size_t size;
+
+/*
+ * Grow the CPU mask as needed.
+ *
+ * Other ways of determining the number of CPUs available on the system:
+ * - inspecting the contents of /proc/cpuinfo
+ * - using sysconf(3) to obtain _SC_NPROCESSORS_CONF and _SC_NPROCESSORS_ONLN
+ * - inspecting the list of CPU directories under /sys/devices/system/cpu/
+ */
+int grow_mask() {
+	ncpus = 1024;
+	while ((mask = CPU_ALLOC(ncpus)) != NULL &&
+	       sched_getaffinity(0, CPU_ALLOC_SIZE(ncpus), mask) != 0 &&
+	       errno == EINVAL) {
+		CPU_FREE(mask);
+		errno = 0;
+		ncpus *= 2;
+	}
+	if (mask == NULL || (errno != 0 && errno != EINVAL))
+		return 1;
+	size = CPU_ALLOC_SIZE(ncpus);
+	return 0;
+}
+
+int bind_to_cpu(size_t cpu) {
+	CPU_ZERO_S(size, mask);
+	CPU_SET_S(cpu, size, mask);
+	if (sched_setaffinity(0, size, mask) != 0)
+		return 1;
+	return 0;
+}
+
+int main(int c, char **v) {
+	int i, fd = open("/dev/null", O_WRONLY);
+
+	if (fd == -1)
+		return 1;
+
+	if (grow_mask() == -1)
+		return 1;
+
+	/* Loop over CPUs (in argv[]). */
+        for (i = 1; i < c; i++) {
+		/* Bind to CPU. */
+		if (bind_to_cpu(atol(v[i])) == -1)
+			return 1;
+
+		/* Call write() from CPU. */
+		write(fd, &i, sizeof(i));
+	}
+
+	close(fd);
+	CPU_FREE(mask);
+
+	return 0;
+}
+EOF
+
+gcc main.c
+if [ $? -ne 0 ]; then
+	echo ERROR compilation failed
+	exit 1
+fi
+
+#
+# Get CPU list and form expected-results file.
+#
+
+cpulist=`awk '/^processor[ 	]: [0-9]*$/ { print $3 }' /proc/cpuinfo`
+echo $cpulist
+
+echo > expect.txt
+for cpu in $cpulist; do
+	echo $cpu >> expect.txt
+done
+
+#
+# Run DTrace (without -xcpu).  Check that all CPUs appear.
+#
+
+$dtrace $dt_flags \
+    -qn 'syscall::write:entry { printf("%d\n", cpu); }' \
+    -c "./a.out $cpulist" | sort | uniq > actual.txt
+if [ $? -ne 0 ]; then
+	echo ERROR dtrace failed
+	exit 1
+fi
+
+if ! diff -q expect.txt actual.txt > /dev/null; then
+	echo ERROR did not see expected CPUs in baseline case
+	echo expect $cpulist
+	echo actual:
+	cat actual.txt
+	exit 1
+fi
+
+#
+# Run DTrace (with -xcpu).  Check that only the specified CPU appears.
+#
+
+nerr=0
+for cpu0 in $cpulist; do
+	$dtrace $dt_flags -xcpu=$cpu0 \
+	    -qn 'syscall::write:entry { printf("%d\n", cpu); }' \
+	    -c "./a.out $cpulist" | sort | uniq > actual.txt
+	echo > expect.txt
+	echo $cpu0 >> expect.txt
+
+	if ! diff -q expect.txt actual.txt > /dev/null; then
+		echo ERROR did not see expected CPUs in cpu $cpu0 case, saw:
+		cat actual.txt
+		nerr=$(($nerr + 1))
+	fi
+done
+
+exit $nerr
diff --git a/test/unittest/options/tst.cpu-syscall.sh b/test/unittest/options/tst.cpu-syscall.sh
index 8713e9d4..f598da12 100755
--- a/test/unittest/options/tst.cpu-syscall.sh
+++ b/test/unittest/options/tst.cpu-syscall.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 # Oracle Linux DTrace.
-# Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
 # Licensed under the Universal Permissive License v 1.0 as shown at
 # http://oss.oracle.com/licenses/upl.
 #
@@ -129,23 +129,28 @@ if ! diff -q expect.txt actual.txt > /dev/null; then
 	exit 1
 fi
 
+#
+# Pick a CPU at random.
+#
+
+cpus=( $cpulist )
+ncpus=${#cpus[@]}
+cpu0=${cpus[$((RANDOM % $ncpus))]}
+
 #
 # Run DTrace (with -xcpu).  Check that only the specified CPU appears.
 #
 
-nerr=0
-for cpu0 in $cpulist; do
-	$dtrace $dt_flags -xcpu=$cpu0 \
-	    -qn 'syscall::write:entry { printf("%d\n", cpu); }' \
-	    -c "./a.out $cpulist" | sort | uniq > actual.txt
-	echo > expect.txt
-	echo $cpu0 >> expect.txt
-
-	if ! diff -q expect.txt actual.txt > /dev/null; then
-		echo ERROR did not see expected CPUs in cpu $cpu0 case, saw:
-		cat actual.txt
-		nerr=$(($nerr + 1))
-	fi
-done
+$dtrace $dt_flags -xcpu=$cpu0 \
+    -qn 'syscall::write:entry { printf("%d\n", cpu); }' \
+    -c "./a.out $cpulist" | sort | uniq > actual.txt
+echo > expect.txt
+echo $cpu0 >> expect.txt
+
+if ! diff -q expect.txt actual.txt > /dev/null; then
+	echo ERROR did not see expected CPUs in cpu $cpu0 case, saw:
+	cat actual.txt
+	exit 1
+fi
 
-exit $nerr
+exit 0
-- 
2.18.4