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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-18 08:19:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-18 08:19:03 -0700
commit4d7b4ac22fbec1a03206c6cde353f2fd6942f828 (patch)
tree2d96a9e9c28cf6fa628a278decc00ad55a8b043b /Documentation
parent3aaf51ace5975050ab43c7d4d7e439e0ae7d13d7 (diff)
parent94f3ca95787ada3d64339a4ecb2754236ab563f6 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits) perf tools: Add mode to build without newt support perf symbols: symbol inconsistency message should be done only at verbose=1 perf tui: Add explicit -lslang option perf options: Type check all the remaining OPT_ variants perf options: Type check OPT_BOOLEAN and fix the offenders perf options: Check v type in OPT_U?INTEGER perf options: Introduce OPT_UINTEGER perf tui: Add workaround for slang < 2.1.4 perf record: Fix bug mismatch with -c option definition perf options: Introduce OPT_U64 perf tui: Add help window to show key associations perf tui: Make <- exit menus too perf newt: Add single key shortcuts for zoom into DSO and threads perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed perf newt: Fix the 'A'/'a' shortcut for annotate perf newt: Make <- exit the ui_browser x86, perf: P4 PMU - fix counters management logic perf newt: Make <- zoom out filters perf report: Report number of events, not samples perf hist: Clarify events_stats fields usage ... Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kprobes.txt10
-rw-r--r--Documentation/trace/kprobetrace.txt4
2 files changed, 5 insertions, 9 deletions
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 2f9115c0ae6..61c291cddf1 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -165,8 +165,8 @@ the user entry_handler invocation is also skipped.
1.4 How Does Jump Optimization Work?
-If you configured your kernel with CONFIG_OPTPROBES=y (currently
-this option is supported on x86/x86-64, non-preemptive kernel) and
+If your kernel is built with CONFIG_OPTPROBES=y (currently this flag
+is automatically set 'y' on x86/x86-64, non-preemptive kernel) and
the "debug.kprobes_optimization" kernel parameter is set to 1 (see
sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a jump
instruction instead of a breakpoint instruction at each probepoint.
@@ -271,8 +271,6 @@ tweak the kernel's execution path, you need to suppress optimization,
using one of the following techniques:
- Specify an empty function for the kprobe's post_handler or break_handler.
or
-- Config CONFIG_OPTPROBES=n.
- or
- Execute 'sysctl -w debug.kprobes_optimization=n'
2. Architectures Supported
@@ -307,10 +305,6 @@ it useful to "Compile the kernel with debug info" (CONFIG_DEBUG_INFO),
so you can use "objdump -d -l vmlinux" to see the source-to-object
code mapping.
-If you want to reduce probing overhead, set "Kprobes jump optimization
-support" (CONFIG_OPTPROBES) to "y". You can find this option under the
-"Kprobes" line.
-
4. API Reference
The Kprobes API includes a "register" function and an "unregister"
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index a9100b28eb8..ec94748ae65 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -40,7 +40,9 @@ Synopsis of kprobe_events
$stack : Fetch stack address.
$retval : Fetch return value.(*)
+|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
- NAME=FETCHARG: Set NAME as the argument name of FETCHARG.
+ NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
+ FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
+ (u8/u16/u32/u64/s8/s16/s32/s64) are supported.
(*) only for return probe.
(**) this is useful for fetching a field of data structures.