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| author | Ross Zwisler <zwisler@chromium.org> | 2023-01-25 22:32:51 +0100 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2023-01-31 22:02:30 +0100 |
| commit | 2abfcd293b79baf62895894fa3ea2386ffbe6338 (patch) | |
| tree | b74867f24b7c6d6b6909856063d6c184a29195e0 /Documentation/trace/events-nmi.rst | |
| parent | Doc/damon: fix the data path error (diff) | |
| download | linux-2abfcd293b79baf62895894fa3ea2386ffbe6338.tar.xz linux-2abfcd293b79baf62895894fa3ea2386ffbe6338.zip | |
docs: ftrace: always use canonical ftrace path
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Many parts of Documentation still reference this older debugfs path, so
let's update them to avoid confusion.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230125213251.2013791-1-zwisler@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/trace/events-nmi.rst')
| -rw-r--r-- | Documentation/trace/events-nmi.rst | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/trace/events-nmi.rst b/Documentation/trace/events-nmi.rst index 9e0a7289d80a..22ac1be0ea6f 100644 --- a/Documentation/trace/events-nmi.rst +++ b/Documentation/trace/events-nmi.rst @@ -4,7 +4,7 @@ NMI Trace Events These events normally show up here: - /sys/kernel/debug/tracing/events/nmi + /sys/kernel/tracing/events/nmi nmi_handler @@ -31,13 +31,13 @@ really hogging a lot of CPU time, like a millisecond at a time. Note that the kernel's output is in milliseconds, but the input to the filter is in nanoseconds! You can filter on 'delta_ns':: - cd /sys/kernel/debug/tracing/events/nmi/nmi_handler + cd /sys/kernel/tracing/events/nmi/nmi_handler echo 'handler==0xffffffff81625600 && delta_ns>1000000' > filter echo 1 > enable Your output would then look like:: - $ cat /sys/kernel/debug/tracing/trace_pipe + $ cat /sys/kernel/tracing/trace_pipe <idle>-0 [000] d.h3 505.397558: nmi_handler: perf_event_nmi_handler() delta_ns: 3236765 handled: 1 <idle>-0 [000] d.h3 505.805893: nmi_handler: perf_event_nmi_handler() delta_ns: 3174234 handled: 1 <idle>-0 [000] d.h3 506.158206: nmi_handler: perf_event_nmi_handler() delta_ns: 3084642 handled: 1 |