On Sun, 18 Aug 2024 00:06:20 +0900 Masami Hiramatsu (Google) mhiramat@kernel.org wrote:
On Fri, 16 Aug 2024 08:04:41 -0600 Shuah Khan skhan@linuxfoundation.org wrote:
On 8/15/24 20:31, Masami Hiramatsu (Google) wrote:
From: Masami Hiramatsu (Google) mhiramat@kernel.org
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.
Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org
Changes in v4:
- Use getopt() in poll.c (command options are changed)
- Update test code according to the new command options.
Changes in v2:
- Update poll command to support both of POLLIN and POLLPRI, and timeout.
- Identify unsupported stable kernel if poll-in returns soon.
- Test both of POLLIN and POLLPRI.
tools/testing/selftests/ftrace/Makefile | 2 + tools/testing/selftests/ftrace/poll.c | 74 ++++++++++++++++++++ .../ftrace/test.d/trigger/trigger-hist-poll.tc | 74 ++++++++++++++++++++ 3 files changed, 150 insertions(+) create mode 100644 tools/testing/selftests/ftrace/poll.c create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc
diff --git a/tools/testing/selftests/ftrace/Makefile b/tools/testing/selftests/ftrace/Makefile index a1e955d2de4c..49d96bb16355 100644 --- a/tools/testing/selftests/ftrace/Makefile +++ b/tools/testing/selftests/ftrace/Makefile @@ -6,4 +6,6 @@ TEST_PROGS := ftracetest-ktap TEST_FILES := test.d settings EXTRA_CLEAN := $(OUTPUT)/logs/* +TEST_GEN_PROGS = poll
- include ../lib.mk
diff --git a/tools/testing/selftests/ftrace/poll.c b/tools/testing/selftests/ftrace/poll.c new file mode 100644 index 000000000000..584f159654b1 --- /dev/null +++ b/tools/testing/selftests/ftrace/poll.c @@ -0,0 +1,74 @@ +// 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, return code is 0 */
Looks like you missed this one :) Otherwise looks good to me.
Oops, indeed.
Hm, this comment is correct but misleadable. I meant that the poll() returns 0 if timeout happens.
----- RETURN VALUE On success, poll() returns a nonnegative value which is the number of elements in the pollfds whose revents fields have been set to a nonzero value (indicating an event or an error). A return value of zero indicates that the system call timed out before any file descriptors became read. -----
But the comment should tell what this command does.
Thanks,
With this fixed
Reviewed-by: Shuah Khan skhan@linuxfoundation.org
Thanks!
thanks, -- Shuah
-- Masami Hiramatsu (Google) mhiramat@kernel.org