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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-03-31 17:23:45 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-04-08 10:58:35 -0400 |
| commit | 9828413d4715d4ed12bc92b161f4ed377d777ffb (patch) | |
| tree | 78c05d662c762ed127ad215b3e34b367f39bbb70 /kernel/trace/Kconfig | |
| parent | 91df6089aa330f12f31cf4b710350a3d6e3d66e6 (diff) | |
| download | blackbird-op-linux-9828413d4715d4ed12bc92b161f4ed377d777ffb.tar.gz blackbird-op-linux-9828413d4715d4ed12bc92b161f4ed377d777ffb.zip | |
tracing: Add enum_map file to show enums that have been mapped
Add a enum_map file in the tracing directory to see what enums have been
saved to convert in the print fmt files.
As this requires the enum mapping to be persistent in memory, it is only
created if the new config option CONFIG_TRACE_ENUM_MAP_FILE is enabled.
This is for debugging and will increase the persistent memory footprint
of the kernel.
Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/Kconfig')
| -rw-r--r-- | kernel/trace/Kconfig | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a5da09c899dd..fedbdd7d5d1e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -599,6 +599,34 @@ config RING_BUFFER_STARTUP_TEST If unsure, say N +config TRACE_ENUM_MAP_FILE + bool "Show enum mappings for trace events" + depends on TRACING + help + The "print fmt" of the trace events will show the enum names instead + of their values. This can cause problems for user space tools that + use this string to parse the raw data as user space does not know + how to convert the string to its value. + + To fix this, there's a special macro in the kernel that can be used + to convert the enum into its value. If this macro is used, then the + print fmt strings will have the enums converted to their values. + + If something does not get converted properly, this option can be + used to show what enums the kernel tried to convert. + + This option is for debugging the enum conversions. A file is created + in the tracing directory called "enum_map" that will show the enum + names matched with their values and what trace event system they + belong too. + + Normally, the mapping of the strings to values will be freed after + boot up or module load. With this option, they will not be freed, as + they are needed for the "enum_map" file. Enabling this option will + increase the memory footprint of the running kernel. + + If unsure, say N + endif # FTRACE endif # TRACING_SUPPORT |
