Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
commands/bthread.c | 142 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 142 insertions(+)
create mode 100644 commands/bthread.c
diff --git a/commands/bthread.c b/commands/bthread.c
new file mode 100644
index 000000000000..1fd782f03f43
--- /dev/null
+++ b/commands/bthread.c
@@ -0,0 +1,142 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Ahmad Fatoum, Pengutronix
+ */
+
+#include <bthread.h>
+#include <errno.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <command.h>
+#include <getopt.h>
+#include <clock.h>
+
+static int bthread_time(void)
+{
+ uint64_t start = get_time_ns();
+ int i = 0;
+
+ /*
+ * How many background tasks can we have in one second?
+ *
+ * A low number here may point to problems with bthreads taking too
+ * much time.
+ */
+ while (!is_timeout(start, SECOND))
+ i++;
+
+ return i;
+}
+
+static int bthread_infinite(void *data)
+{
+ while (!bthread_should_stop())
+ ;
+
+ return 0;
+}
+
+static int bthread_isolated_time(void)
+{
+ uint64_t start = get_time_ns();
+ struct bthread *bthread;
+ int i = 0;
+
+ bthread = bthread_create(bthread_infinite, NULL, "infinite");
+ if (!bthread)
+ return -ENOMEM;
+
+ bthread_wake(bthread);
+
+ /*
+ * How many context switches can we do in one second?
+ *
+ * A low number here may point to problems with bthreads taking too
+ * much time.
+ */
+ while (!is_timeout_non_interruptible(start, SECOND)) {
+ bthread_schedule(bthread);
+ i += 2;
+ }
+
+ bthread_stop(bthread);
+ bthread_free(bthread);
+
+ return i;
+}
+
+static int bthread_printer(void *arg)
+{
+ volatile u64 start;
+ volatile int i = 0;
+ start = get_time_ns();
+
+ while (!bthread_should_stop()) {
+ if (!is_timeout_non_interruptible(start, 225 * MSECOND))
+ continue;
+
+ printf("%s yield #%d\n", __func__, ++i);
+ start = get_time_ns();
+ }
+
+ return i;
+}
+
+BAREBOX_CMD_HELP_START(bthread)
+ BAREBOX_CMD_HELP_TEXT("print info about registered barebox threads")
+ BAREBOX_CMD_HELP_TEXT("")
+ BAREBOX_CMD_HELP_TEXT("Options:")
+ BAREBOX_CMD_HELP_OPT ("-i", "Print information about registered bthreads")
+ BAREBOX_CMD_HELP_OPT ("-t", "measure how many bthreads we currently run in 1s")
+ BAREBOX_CMD_HELP_OPT ("-c", "count maximum context switches in 1s")
+ BAREBOX_CMD_HELP_OPT ("-v", "verify correct bthread operation")
+ BAREBOX_CMD_HELP_END
+
+static int do_bthread(int argc, char *argv[])
+{
+ struct bthread *bthread = NULL;
+ int ret, opt;
+ int yields;
+
+ while ((opt = getopt(argc, argv, "itcv")) > 0) {
+ switch (opt) {
+ case 'i':
+ bthread_info();
+ return 0;
+ case 'c':
+ yields = bthread_isolated_time();
+ printf("%d bthread context switches possible in 1s\n", yields);
+ break;
+ case 'v':
+ bthread = bthread_create(bthread_printer, NULL, "bthread");
+ if (!bthread)
+ return -ENOMEM;
+
+ bthread_wake(bthread);
+
+ /* fallthrough */
+ case 't':
+ yields = bthread_time();
+ printf("%d bthread yield calls in 1s\n", yields);
+ }
+
+ if (bthread) {
+ ret = bthread_stop(bthread);
+ bthread_free(bthread);
+
+ if (ret != 4 || yields < ret)
+ return COMMAND_ERROR;
+ }
+
+ return 0;
+ }
+
+ return COMMAND_ERROR_USAGE;
+}
+
+BAREBOX_CMD_START(bthread)
+ .cmd = do_bthread,
+ BAREBOX_CMD_DESC("print info about registered bthreads")
+ BAREBOX_CMD_GROUP(CMD_GRP_MISC)
+ BAREBOX_CMD_HELP(cmd_bthread_help)
+BAREBOX_CMD_END
--
2.29.2
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