Commit 80c3e285 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google) Committed by Steven Rostedt (Google)
Browse files

selftests/tracing: Add hist poll() support test 

Add a testcase for poll() on hist file. This introduces a helper binary
to the ftracetest, because there is no good way to reliably execute
poll() on hist file.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173547867935.569911.10127126796879854182.stgit@devnote2


Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 66fc6f52

tools/testing/selftests/ftrace/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -6,4 +6,6 @@ TEST_PROGS := ftracetest-ktap 
TEST_FILES := test.d settings

EXTRA_CLEAN := $(OUTPUT)/logs/*



TEST_GEN_PROGS = poll



include ../lib.mk

tools/testing/selftests/ftrace/poll.c

0 → 100644
+74 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Simple poll on a file.

 *

 * Copyright (c) 2024 Google LLC.

 */



#include <errno.h>

#include <fcntl.h>

#include <poll.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>



#define BUFSIZE 4096



/*

 * Usage:

 *  poll [-I|-P] [-t timeout] FILE

 */

int main(int argc, char *argv[])

{

	struct pollfd pfd = {.events = POLLIN};

	char buf[BUFSIZE];

	int timeout = -1;

	int ret, opt;



	while ((opt = getopt(argc, argv, "IPt:")) != -1) {

		switch (opt) {

		case 'I':

			pfd.events = POLLIN;

			break;

		case 'P':

			pfd.events = POLLPRI;

			break;

		case 't':

			timeout = atoi(optarg);

			break;

		default:

			fprintf(stderr, "Usage: %s [-I|-P] [-t timeout] FILE\n",

				argv[0]);

			return -1;

		}

	}

	if (optind >= argc) {

		fprintf(stderr, "Error: Polling file is not specified\n");

		return -1;

	}



	pfd.fd = open(argv[optind], O_RDONLY);

	if (pfd.fd < 0) {

		fprintf(stderr, "failed to open %s", argv[optind]);

		perror("open");

		return -1;

	}



	/* Reset poll by read if POLLIN is specified. */

	if (pfd.events & POLLIN)

		do {} while (read(pfd.fd, buf, BUFSIZE) == BUFSIZE);



	ret = poll(&pfd, 1, timeout);

	if (ret < 0 && errno != EINTR) {

		perror("poll");

		return -1;

	}

	close(pfd.fd);



	/* If timeout happned (ret == 0), exit code is 1 */

	if (ret == 0)

		return 1;



	return 0;

}

tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc

0 → 100644
+74 −0
Original line number Diff line number Diff line 
#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: event trigger - test poll wait on histogram

# requires: set_event events/sched/sched_process_free/trigger events/sched/sched_process_free/hist

# flags: instance



POLL=${FTRACETEST_ROOT}/poll



if [ ! -x ${POLL} ]; then

  echo "poll program is not compiled!"

  exit_unresolved

fi



EVENT=events/sched/sched_process_free/



# Check poll ops is supported. Before implementing poll on hist file, it

# returns soon with POLLIN | POLLOUT, but not POLLPRI.



# This must wait >1 sec and return 1 (timeout).

set +e

${POLL} -I -t 1000 ${EVENT}/hist

ret=$?

set -e

if [ ${ret} != 1 ]; then

  echo "poll on hist file is not supported"

  exit_unsupported

fi



# Test POLLIN

echo > trace

echo 'hist:key=comm if comm =="sleep"' > ${EVENT}/trigger

echo 1 > ${EVENT}/enable



# This sleep command will exit after 2 seconds.

sleep 2 &

BGPID=$!

# if timeout happens, poll returns 1.

${POLL} -I -t 4000 ${EVENT}/hist

echo 0 > tracing_on



if [ -d /proc/${BGPID} ]; then

  echo "poll exits too soon"

  kill -KILL ${BGPID} ||:

  exit_fail

fi



if ! grep -qw "sleep" trace; then

  echo "poll exits before event happens"

  exit_fail

fi



# Test POLLPRI

echo > trace

echo 1 > tracing_on



# This sleep command will exit after 2 seconds.

sleep 2 &

BGPID=$!

# if timeout happens, poll returns 1.

${POLL} -P -t 4000 ${EVENT}/hist

echo 0 > tracing_on



if [ -d /proc/${BGPID} ]; then

  echo "poll exits too soon"

  kill -KILL ${BGPID} ||:

  exit_fail

fi



if ! grep -qw "sleep" trace; then

  echo "poll exits before event happens"

  exit_fail

fi



exit_pass