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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-11 09:02:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-11 09:02:09 -0700
commitc72bb316916b1a6cf35e1d5238566ef27b0b7f80 (patch)
tree1bd7bb147302abf907bba9fb83cf74b4a5b6ef0d /Documentation
parent6d128e1e72bf082542e85f72e6b7ddd704193588 (diff)
parentdcc302232c1f9b3ca16f6b8ee190eb0b1a8a0da3 (diff)
Merge tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing changes from Steven Rostedt: "The majority of the changes here are cleanups for the large changes that were added to 3.10, which includes several bug fixes that have been marked for stable. As for new features, there were a few, but nothing to write to LWN about. These include: New function trigger called "dump" and "cpudump" that will cause ftrace to dump its buffer to the console when the function is called. The difference between "dump" and "cpudump" is that "dump" will dump the entire contents of the ftrace buffer, where as "cpudump" will only dump the contents of the ftrace buffer for the CPU that called the function. Another small enhancement is a new sysctl switch called "traceoff_on_warning" which, when enabled, will disable tracing if any WARN_ON() is triggered. This is useful if you want to debug what caused a warning and do not want to risk losing your trace data by the ring buffer overwriting the data before you can disable it. There's also a kernel command line option that will make this enabled at boot up called the same thing" * tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (34 commits) tracing: Make tracing_open_generic_{tr,tc}() static tracing: Remove ftrace() function tracing: Remove TRACE_EVENT_TYPE enum definition tracing: Make tracer_tracing_{off,on,is_on}() static tracing: Fix irqs-off tag display in syscall tracing uprobes: Fix return value in error handling path tracing: Fix race between deleting buffer and setting events tracing: Add trace_array_get/put() to event handling tracing: Get trace_array ref counts when accessing trace files tracing: Add trace_array_get/put() to handle instance refs better tracing: Protect ftrace_trace_arrays list in trace_events.c tracing: Make trace_marker use the correct per-instance buffer ftrace: Do not run selftest if command line parameter is set tracing/kprobes: Don't pass addr=ip to perf_trace_buf_submit() tracing: Use flag buffer_disabled for irqsoff tracer tracing/kprobes: Turn trace_probe->files into list_head tracing: Fix disabling of soft disable tracing: Add missing syscall_metadata comment tracing: Simplify code for showing of soft disabled flag tracing/kprobes: Kill probe_enable_lock ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kernel-parameters.txt13
-rw-r--r--Documentation/trace/events.txt15
-rw-r--r--Documentation/trace/ftrace.txt13
3 files changed, 38 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 75236f1972d9..15356aca938c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3081,6 +3081,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
See also Documentation/trace/ftrace.txt "trace options"
section.
+ traceoff_on_warning
+ [FTRACE] enable this option to disable tracing when a
+ warning is hit. This turns off "tracing_on". Tracing can
+ be enabled again by echoing '1' into the "tracing_on"
+ file located in /sys/kernel/debug/tracing/
+
+ This option is useful, as it disables the trace before
+ the WARNING dump is called, which prevents the trace to
+ be filled with content caused by the warning output.
+
+ This option can also be set at run time via the sysctl
+ option: kernel/traceoff_on_warning
+
transparent_hugepage=
[KNL]
Format: [always|madvise|never]
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index bb24c2a0e870..37732a220d33 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -183,13 +183,22 @@ The relational-operators depend on the type of the field being tested:
The operators available for numeric fields are:
-==, !=, <, <=, >, >=
+==, !=, <, <=, >, >=, &
And for string fields they are:
-==, !=
+==, !=, ~
-Currently, only exact string matches are supported.
+The glob (~) only accepts a wild card character (*) at the start and or
+end of the string. For example:
+
+ prev_comm ~ "*sh"
+ prev_comm ~ "sh*"
+ prev_comm ~ "*sh*"
+
+But does not allow for it to be within the string:
+
+ prev_comm ~ "ba*sh" <-- is invalid
5.2 Setting filters
-------------------
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index bfe8c29b1f1d..b937c6e2163c 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -2430,6 +2430,19 @@ The following commands are supported:
echo '!schedule:disable_event:sched:sched_switch' > \
set_ftrace_filter
+- dump
+ When the function is hit, it will dump the contents of the ftrace
+ ring buffer to the console. This is useful if you need to debug
+ something, and want to dump the trace when a certain function
+ is hit. Perhaps its a function that is called before a tripple
+ fault happens and does not allow you to get a regular dump.
+
+- cpudump
+ When the function is hit, it will dump the contents of the ftrace
+ ring buffer for the current CPU to the console. Unlike the "dump"
+ command, it only prints out the contents of the ring buffer for the
+ CPU that executed the function that triggered the dump.
+
trace_pipe
----------