Add -xcpu support to profile provider

Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>

libdtrace/dt_prov_profile.c

@@ -33,7 +33,9 @@ static const dtrace_pattr_t	pattr = {
 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 };
 
-#define FDS_CNT(kind)	((kind) == KIND_TICK ? 1 : dtp->dt_conf.num_online_cpus)
+#define FDS_CNT(kind)	((kind) == KIND_TICK || \
+			 dtp->dt_options[DTRACEOPT_CPU] != DTRACEOPT_UNSET ? \
+			 1 : dtp->dt_conf.num_online_cpus)
 typedef struct profile_probe {
 	int		kind;
 	uint64_t	period;
@@ -274,8 +276,13 @@ static int attach(dtrace_hdl_t *dtp, const dt_probe_t *prp, int bpf_fd)
 	for (i = 0; i < cnt; i++) {
 		int j = i, fd;
 
-		/* if there is only one fd, place it at random */
-		if (cnt == 1)
+		/*
+		 * If -xcpu is set, use that CPU.
+		 * If there is only one fd, place it at random.
+		 */
+		if (dtp->dt_options[DTRACEOPT_CPU] != DTRACEOPT_UNSET)
+			j = dtp->dt_options[DTRACEOPT_CPU];
+		else if (cnt == 1)
 			j = rand() % dtp->dt_conf.num_online_cpus;
 
 		fd = dt_perf_event_open(&attr, -1, dtp->dt_conf.cpus[j].cpu_id,

test/stress/options/tst.cpu-profile.sh

@@ -0,0 +1,27 @@
+#!/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=$1
+
+nerr=0
+
+# Loop over CPUs.
+for cpu0 in `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo`; do
+	# Observe where DTrace runs.
+	cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'profile-100ms { trace(cpu); exit(0); }'`
+
+	# Check result.
+	echo expected cpu $cpu0 got cpu $cpu
+	if [ `echo $cpu | wc -w` -ne 1 ]; then
+		nerr=$(($nerr + 1))
+	elif [ $(($cpu + 0)) != $cpu0 ]; then
+		nerr=$(($nerr + 1))
+	fi
+done
+
+exit $nerr

test/stress/options/tst.cpu-tick.sh

@@ -0,0 +1,27 @@
+#!/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=$1
+
+nerr=0
+
+# Loop over CPUs.
+for cpu0 in `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo`; do
+	# Observe where DTrace runs.
+	cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'tick-100ms { trace(cpu); exit(0); }'`
+
+	# Check result.
+	echo expected cpu $cpu0 got cpu $cpu
+	if [ `echo $cpu | wc -w` -ne 1 ]; then
+		nerr=$(($nerr + 1))
+	elif [ $(($cpu + 0)) != $cpu0 ]; then
+		nerr=$(($nerr + 1))
+	fi
+done
+
+exit $nerr

test/unittest/options/tst.cpu-profile.sh

@@ -0,0 +1,27 @@
+#!/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=$1
+
+# Pick a CPU at random.
+cpulist=( `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo` )
+ncpus=${#cpulist[@]}
+cpu0=${cpulist[$((RANDOM % $ncpus))]}
+
+# Observe where DTrace runs.
+cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'profile-100ms { trace(cpu); exit(0); }'`
+
+# Check result.
+echo expected cpu $cpu0 got cpu $cpu
+if [ `echo $cpu | wc -w` -ne 1 ]; then
+	exit 1
+elif [ $(($cpu + 0)) != $cpu0 ]; then
+	exit 1
+fi
+
+exit 0

test/unittest/options/tst.cpu-tick.sh

@@ -0,0 +1,27 @@
+#!/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=$1
+
+# Pick a CPU at random.
+cpulist=( `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo` )
+ncpus=${#cpulist[@]}
+cpu0=${cpulist[$((RANDOM % $ncpus))]}
+
+# Observe where DTrace runs.
+cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'tick-100ms { trace(cpu); exit(0); }'`
+
+# Check result.
+echo expected cpu $cpu0 got cpu $cpu
+if [ `echo $cpu | wc -w` -ne 1 ]; then
+	exit 1
+elif [ $(($cpu + 0)) != $cpu0 ]; then
+	exit 1
+fi
+
+exit 0