path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 19:58:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 19:58:13 -0800
commit1dd7dcb6eaa677b034e7ef63df8320277507ae70 (patch)
tree3f1592b634d7bdde94e00570925be2dade8433d4 /Documentation
parentMerge branch 'akpm' (patchbomb from Andrew) (diff)
parenttracing: Truncated output is better than nothing (diff)
Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "There was a lot of clean ups and minor fixes. One of those clean ups was to the trace_seq code. It also removed the return values to the trace_seq_*() functions and use trace_seq_has_overflowed() to see if the buffer filled up or not. This is similar to work being done to the seq_file code as well in another tree. Some of the other goodies include: - Added some "!" (NOT) logic to the tracing filter. - Fixed the frame pointer logic to the x86_64 mcount trampolines - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems. That is, the ftrace trampoline can be dynamically allocated and be called directly by functions that only have a single hook to them" * tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits) tracing: Truncated output is better than nothing tracing: Add additional marks to signal very large time deltas Documentation: describe trace_buf_size parameter more accurately tracing: Allow NOT to filter AND and OR clauses tracing: Add NOT to filtering logic ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter ftrace/x86: Get rid of ftrace_caller_setup ftrace/x86: Have save_mcount_regs macro also save stack frames if needed ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs ftrace/x86: Simplify save_mcount_regs on getting RIP ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file ftrace/x86: Have static tracing also use ftrace_caller_setup ftrace/x86: Have static function tracing always test for function graph kprobes: Add IPMODIFY flag to kprobe_ftrace_ops ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes/ftrace: Recover original IP if pre_handler doesn't change it tracing/trivial: Fix typos and make an int into a bool tracing: Deletion of an unnecessary check before iput() ...
Diffstat (limited to 'Documentation')
2 files changed, 13 insertions, 4 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d6eb3636fe5a..32ba9ea5934a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3520,7 +3520,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
are saved.
- [FTRACE] will set tracing buffer size.
+ [FTRACE] will set tracing buffer size on each cpu.
[FTRACE] Set and start specified trace events in order
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 4da42616939f..8408e040f06f 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -234,6 +234,11 @@ of ftrace. Here is a list of some of the key files:
will be displayed on the same line as the function that
is returning registers.
+ If the callback registered to be traced by a function with
+ the "ip modify" attribute (thus the regs->ip can be changed),
+ an 'I' will be displayed on the same line as the function that
+ can be overridden.
When set it will enable all functions with either the function
@@ -680,9 +685,11 @@ The above is mostly meaningful for kernel developers.
needs to be fixed to be only relative to the same CPU.
The marks are determined by the difference between this
current trace and the next trace.
- '!' - greater than preempt_mark_thresh (default 100)
- '+' - greater than 1 microsecond
- ' ' - less than or equal to 1 microsecond.
+ '$' - greater than 1 second
+ '#' - greater than 1000 microsecond
+ '!' - greater than 100 microsecond
+ '+' - greater than 10 microsecond
+ ' ' - less than or equal to 10 microsecond.
The rest is the same as the 'trace' file.
@@ -1951,6 +1958,8 @@ want, depending on your needs.
+ means that the function exceeded 10 usecs.
! means that the function exceeded 100 usecs.
+ # means that the function exceeded 1000 usecs.
+ $ means that the function exceeded 1 sec.
- The task/pid field displays the thread cmdline and pid which