diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-11 09:02:09 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-11 09:02:09 -0700 |
commit | c72bb316916b1a6cf35e1d5238566ef27b0b7f80 (patch) | |
tree | 1bd7bb147302abf907bba9fb83cf74b4a5b6ef0d /Documentation | |
parent | 6d128e1e72bf082542e85f72e6b7ddd704193588 (diff) | |
parent | dcc302232c1f9b3ca16f6b8ee190eb0b1a8a0da3 (diff) | |
download | lwn-c72bb316916b1a6cf35e1d5238566ef27b0b7f80.tar.gz lwn-c72bb316916b1a6cf35e1d5238566ef27b0b7f80.zip |
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.txt | 13 | ||||
-rw-r--r-- | Documentation/trace/events.txt | 15 | ||||
-rw-r--r-- | Documentation/trace/ftrace.txt | 13 |
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 ---------- |