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Diffstat (limited to 'Documentation/trace/mmiotrace.rst')
| -rw-r--r-- | Documentation/trace/mmiotrace.rst | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/trace/mmiotrace.rst b/Documentation/trace/mmiotrace.rst index fed13eaead89..95b750722a13 100644 --- a/Documentation/trace/mmiotrace.rst +++ b/Documentation/trace/mmiotrace.rst @@ -36,11 +36,11 @@ Usage Quick Reference :: $ mount -t debugfs debugfs /sys/kernel/debug - $ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer - $ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & + $ echo mmiotrace > /sys/kernel/tracing/current_tracer + $ cat /sys/kernel/tracing/trace_pipe > mydump.txt & Start X or whatever. - $ echo "X is up" > /sys/kernel/debug/tracing/trace_marker - $ echo nop > /sys/kernel/debug/tracing/current_tracer + $ echo "X is up" > /sys/kernel/tracing/trace_marker + $ echo nop > /sys/kernel/tracing/current_tracer Check for lost events. @@ -56,11 +56,11 @@ Check that the driver you are about to trace is not loaded. Activate mmiotrace (requires root privileges):: - $ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer + $ echo mmiotrace > /sys/kernel/tracing/current_tracer Start storing the trace:: - $ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & + $ cat /sys/kernel/tracing/trace_pipe > mydump.txt & The 'cat' process should stay running (sleeping) in the background. @@ -68,14 +68,14 @@ 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" > /sys/kernel/debug/tracing/trace_marker +$ echo "X is up" > /sys/kernel/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 > /sys/kernel/debug/tracing/current_tracer + $ echo nop > /sys/kernel/tracing/current_tracer The 'cat' process exits. If it does not, kill it by issuing 'fg' command and pressing ctrl+c. @@ -93,12 +93,12 @@ 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 /sys/kernel/debug/tracing/buffer_size_kb + $ cat /sys/kernel/tracing/buffer_size_kb gives you a number. Approximately double this number and write it back, for instance:: - $ echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb + $ echo 128000 > /sys/kernel/tracing/buffer_size_kb Then start again from the top. |