diff mbox

[igt,02/24] lib: Add hooks for enabling ftrace

Message ID 20170814201848.28216-2-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Wilson Aug. 14, 2017, 8:18 p.m. UTC
If the kernel has tracing support builtin, we can enable around
troublesome tests to obtain greater detail from the kernel that may
prove invaluable in debugging the problem.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 lib/Makefile.sources |   2 +
 lib/igt_core.c       |   5 ++
 lib/igt_ftrace.c     | 181 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_ftrace.h     |  46 +++++++++++++
 4 files changed, 234 insertions(+)
 create mode 100644 lib/igt_ftrace.c
 create mode 100644 lib/igt_ftrace.h
diff mbox

Patch

diff --git a/lib/Makefile.sources b/lib/Makefile.sources
index 53fdb54c..90ff6468 100644
--- a/lib/Makefile.sources
+++ b/lib/Makefile.sources
@@ -12,6 +12,8 @@  lib_source_list =	 	\
 	igt_aux.c		\
 	igt_aux.h		\
 	igt_edid_template.h	\
+	igt_ftrace.c		\
+	igt_ftrace.h		\
 	igt_gt.c		\
 	igt_gt.h		\
 	igt_gvt.c		\
diff --git a/lib/igt_core.c b/lib/igt_core.c
index 9eb99eda..ce8482a1 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -63,6 +63,7 @@ 
 #include "intel_chipset.h"
 #include "intel_io.h"
 #include "igt_debugfs.h"
+#include "igt_ftrace.h"
 #include "version.h"
 #include "config.h"
 
@@ -563,6 +564,8 @@  static void low_mem_killer_disable(bool disable)
 bool igt_exit_called;
 static void common_exit_handler(int sig)
 {
+	igt_ftrace_close();
+
 	if (!igt_only_list_subtests()) {
 		low_mem_killer_disable(false);
 		kick_fbcon(true);
@@ -856,6 +859,8 @@  out:
 
 		oom_adjust_for_doom();
 		low_mem_killer_disable(true);
+
+		igt_ftrace_open();
 	}
 
 	/* install exit handler, to ensure we clean up */
diff --git a/lib/igt_ftrace.c b/lib/igt_ftrace.c
new file mode 100644
index 00000000..5b618f11
--- /dev/null
+++ b/lib/igt_ftrace.c
@@ -0,0 +1,181 @@ 
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "igt.h"
+#include "igt_ftrace.h"
+#include "igt_debugfs.h"
+#include "igt_sysfs.h"
+
+#define BIT(x) (1ul << (x))
+
+/* Only a single tracer in the kernel, so we can use a singleton */
+struct igt_ftrace {
+	int dir;
+
+	unsigned long flags;
+#define PID_SET BIT(0)
+#define INCLUDE_SET BIT(1)
+#define EXCLUDE_SET BIT(2)
+
+} igt_ftrace = { -1 };
+
+int igt_ftrace_open(void)
+{
+	int dir;
+	int err;
+
+	dir = open(igt_debugfs_mount(), O_RDONLY);
+	if (dir < 0)
+		return -errno;
+
+	igt_ftrace.dir = openat(dir, "tracing", O_RDONLY);
+	close(dir);
+	if (igt_ftrace.dir < 0)
+		return -errno;
+
+	err = igt_ftrace_disable();
+	if (err)
+		goto ft_close;
+
+	return 0;
+
+ft_close:
+	close(igt_ftrace.dir);
+	igt_ftrace.dir = -1;
+	return err;
+}
+
+int __igt_ftrace_enable(const char *mode,
+			const struct igt_ftrace_options *opts)
+{
+	int err;
+
+	if (igt_ftrace.dir < 0)
+		return -ENODEV;
+
+	if (!mode)
+		return -EINVAL;
+
+	err = igt_sysfs_set(igt_ftrace.dir, "current_tracer", mode);
+	if (err < 0)
+		return err;
+
+	if (opts && opts->pid) {
+		err = igt_sysfs_printf(igt_ftrace.dir,
+				       "set_ftrace_pid", "%d",
+				       opts->pid);
+		if (err < 0)
+			goto disable;
+
+		igt_ftrace.flags |= PID_SET;
+	}
+
+	if (opts && opts->include) {
+		err = igt_sysfs_set(igt_ftrace.dir,
+				    "set_ftrace_filter",
+				    opts->include);
+		if (err < 0)
+			goto disable;
+
+		igt_ftrace.flags |= INCLUDE_SET;
+	}
+
+	if (opts && opts->exclude) {
+		err = igt_sysfs_set(igt_ftrace.dir,
+				    "set_ftrace_notrace",
+				    opts->exclude);
+		if (err < 0)
+			goto disable;
+
+		igt_ftrace.flags |= EXCLUDE_SET;
+	}
+
+	err = igt_sysfs_set(igt_ftrace.dir, "tracer_on", "1");
+	if (err < 0)
+		return err;
+
+	return 0;
+
+disable:
+	igt_ftrace_disable();
+	return err;
+}
+
+int igt_ftrace_disable(void)
+{
+	int err;
+
+	if (igt_ftrace.dir < 0)
+		return -ENODEV;
+
+	err = igt_sysfs_set(igt_ftrace.dir, "tracer_on", "0");
+	if (err < 0)
+		return err;
+
+	if (igt_ftrace.flags & PID_SET) {
+		igt_sysfs_set(igt_ftrace.dir, "set_ftrace_pid", "");
+		igt_ftrace.flags &= ~PID_SET;
+	}
+
+	if (igt_ftrace.flags & INCLUDE_SET) {
+		igt_sysfs_set(igt_ftrace.dir, "set_ftrace_filter", "");
+		igt_ftrace.flags &= ~INCLUDE_SET;
+	}
+
+	if (igt_ftrace.flags & EXCLUDE_SET) {
+		igt_sysfs_set(igt_ftrace.dir, "set_ftrace_notrace", "");
+		igt_ftrace.flags &= ~EXCLUDE_SET;
+	}
+
+	return 0;
+}
+
+void igt_ftrace_dump(const char *header)
+{
+	char *txt;
+
+	if (igt_ftrace.dir < 0)
+		return;
+
+	txt = igt_sysfs_get(igt_ftrace.dir, "trace");
+	if (!txt)
+		return;
+
+	igt_info("%s:\n%s", header, txt);
+	free(txt);
+}
+
+void igt_ftrace_close(void)
+{
+	if (igt_ftrace.dir < 0)
+		return;
+
+	close(igt_ftrace.dir);
+	igt_ftrace.dir = -1;
+}
diff --git a/lib/igt_ftrace.h b/lib/igt_ftrace.h
new file mode 100644
index 00000000..3dd67682
--- /dev/null
+++ b/lib/igt_ftrace.h
@@ -0,0 +1,46 @@ 
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef IGT_FTRACE_H
+#define IGT_FTRACE_H
+
+int igt_ftrace_open(void);
+
+struct igt_ftrace_options {
+	int pid;
+	const char *include;
+	const char *exclude;
+};
+
+int __igt_ftrace_enable(const char *mode,
+			const struct igt_ftrace_options *opts);
+#define igt_ftrace_enable() __igt_ftrace_enable("function_graph", NULL)
+
+int igt_ftrace_disable(void);
+
+void igt_ftrace_dump(const char *header);
+
+void igt_ftrace_close(void);
+
+#endif /* IGT_FTRACE_H */