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>
Add a new Documentation/trace/histogram-design.rst file describing the
ftrace histogram low-level design, meant to help developers trying to
understand the internals when extending or making use of the hist
triggers for higher-level tools.
This documentation refers to the hist_debug files implemented by
'tracing: Add hist_debug trace event files for histogram debugging' so
users wishing to try out the test examples here should make sure
CONFIG_HIST_TRIGGERS_DEBUG is enabled.
Link: http://lkml.kernel.org/r/256b29c3274bb89a10157c4a8d1a8bce7e74849e.1585941485.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
