From 156f5a7801195fa2ce44aeeb62d6cf8468f3332a Mon Sep 17 00:00:00 2001 From: GeunSik Lim Date: Tue, 2 Jun 2009 15:01:37 +0900 Subject: debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/" directory name to mount debugfs filesystem for ftrace according to ./Documentation/tracers/ftrace.txt file. And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is existed in kernel source like ftrace, DRM, Wireless, Documentation, Network[sky2]files to mount debugfs filesystem. debugfs means debug filesystem for debugging easy to use by greg kroah hartman. "/sys/kernel/debug/" name is suitable as directory name of debugfs filesystem. - debugfs related reference: http://lwn.net/Articles/334546/ Fix inconsistency of directory name to mount debugfs filesystem. * From Steven Rostedt - find_debugfs() and tracing_files() in this patch. Signed-off-by: GeunSik Lim Acked-by : Inaky Perez-Gonzalez Reviewed-by : Steven Rostedt Reviewed-by : James Smart CC: Jiri Kosina CC: David Airlie CC: Peter Osterlund CC: Ananth N Mavinakayanahalli CC: Anil S Keshavamurthy CC: Masami Hiramatsu Signed-off-by: Greg Kroah-Hartman --- Documentation/trace/mmiotrace.txt | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'Documentation/trace/mmiotrace.txt') diff --git a/Documentation/trace/mmiotrace.txt b/Documentation/trace/mmiotrace.txt index 5731c67abc5..162effbfbde 100644 --- a/Documentation/trace/mmiotrace.txt +++ b/Documentation/trace/mmiotrace.txt @@ -32,41 +32,41 @@ is no way to automatically detect if you are losing events due to CPUs racing. Usage Quick Reference --------------------- -$ mount -t debugfs debugfs /debug -$ echo mmiotrace > /debug/tracing/current_tracer -$ cat /debug/tracing/trace_pipe > mydump.txt & +$ mount -t debugfs debugfs /sys/kernel/debug +$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer +$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & Start X or whatever. -$ echo "X is up" > /debug/tracing/trace_marker -$ echo nop > /debug/tracing/current_tracer +$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker +$ echo nop > /sys/kernel/debug/tracing/current_tracer Check for lost events. Usage ----- -Make sure debugfs is mounted to /debug. If not, (requires root privileges) -$ mount -t debugfs debugfs /debug +Make sure debugfs is mounted to /sys/kernel/debug. If not, (requires root privileges) +$ mount -t debugfs debugfs /sys/kernel/debug Check that the driver you are about to trace is not loaded. Activate mmiotrace (requires root privileges): -$ echo mmiotrace > /debug/tracing/current_tracer +$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer Start storing the trace: -$ cat /debug/tracing/trace_pipe > mydump.txt & +$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & The 'cat' process should stay running (sleeping) in the background. Load the driver you want to trace and use it. Mmiotrace will only catch MMIO accesses to areas that are ioremapped while mmiotrace is active. During tracing you can place comments (markers) into the trace by -$ echo "X is up" > /debug/tracing/trace_marker +$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker This makes it easier to see which part of the (huge) trace corresponds to which action. It is recommended to place descriptive markers about what you do. Shut down mmiotrace (requires root privileges): -$ echo nop > /debug/tracing/current_tracer +$ echo nop > /sys/kernel/debug/tracing/current_tracer The 'cat' process exits. If it does not, kill it by issuing 'fg' command and pressing ctrl+c. @@ -78,10 +78,10 @@ to view your kernel log and look for "mmiotrace has lost events" warning. If events were lost, the trace is incomplete. You should enlarge the buffers and try again. Buffers are enlarged by first seeing how large the current buffers are: -$ cat /debug/tracing/buffer_size_kb +$ cat /sys/kernel/debug/tracing/buffer_size_kb gives you a number. Approximately double this number and write it back, for instance: -$ echo 128000 > /debug/tracing/buffer_size_kb +$ echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb Then start again from the top. If you are doing a trace for a driver project, e.g. Nouveau, you should also -- cgit v1.2.3-70-g09d2