[DTrace-devel] [PATCH 3/5] Add -xcpu support to profile provider

[eugene.loh at oracle.com]

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

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 libdtrace/dt_prov_profile.c              | 13 ++++++++++---
 test/unittest/options/tst.cpu-profile.sh | 20 ++++++++++++++++++++
 test/unittest/options/tst.cpu-tick.sh    | 20 ++++++++++++++++++++
 3 files changed, 50 insertions(+), 3 deletions(-)
 create mode 100755 test/unittest/options/tst.cpu-profile.sh
 create mode 100755 test/unittest/options/tst.cpu-tick.sh

diff --git a/libdtrace/dt_prov_profile.c b/libdtrace/dt_prov_profile.c
index 476dea7c..f3f3bf23 100644
--- a/libdtrace/dt_prov_profile.c
+++ b/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 = perf_event_open(&attr, -1, dtp->dt_conf.cpus[j].cpu_id,
diff --git a/test/unittest/options/tst.cpu-profile.sh b/test/unittest/options/tst.cpu-profile.sh
new file mode 100755
index 00000000..3730ced9
--- /dev/null
+++ b/test/unittest/options/tst.cpu-profile.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2023, 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=$1
+
+nerr=0
+for cpu0 in `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo`; do
+	cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'profile-100ms { trace(cpu); exit(0); }'`
+	echo expected cpu $cpu0 got cpu $cpu
+	if [ $cpu != $cpu0 ]; then
+		nerr=$(($nerr + 1))
+	fi
+done
+
+exit $nerr
diff --git a/test/unittest/options/tst.cpu-tick.sh b/test/unittest/options/tst.cpu-tick.sh
new file mode 100755
index 00000000..c0dbb517
--- /dev/null
+++ b/test/unittest/options/tst.cpu-tick.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2023, 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=$1
+
+nerr=0
+for cpu0 in `awk '/^processor[ 	]*: [0-9]*$/ {print $3}' /proc/cpuinfo`; do
+	cpu=`$dtrace $dt_flags -xcpu=$cpu0 -qn 'tick-100ms { trace(cpu); exit(0); }'`
+	echo expected cpu $cpu0 got cpu $cpu
+	if [ $cpu != $cpu0 ]; then
+		nerr=$(($nerr + 1))
+	fi
+done
+
+exit $nerr
-- 
2.18.4