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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-18 11:19:03 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-18 11:19:03 -0400
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.
165 165
1661.4 How Does Jump Optimization Work? 1661.4 How Does Jump Optimization Work?
167 167
168If you configured your kernel with CONFIG_OPTPROBES=y (currently 168If your kernel is built with CONFIG_OPTPROBES=y (currently this flag
169this option is supported on x86/x86-64, non-preemptive kernel) and 169is automatically set 'y' on x86/x86-64, non-preemptive kernel) and
170the "debug.kprobes_optimization" kernel parameter is set to 1 (see 170the "debug.kprobes_optimization" kernel parameter is set to 1 (see
171sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a jump 171sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a jump
172instruction instead of a breakpoint instruction at each probepoint. 172instruction instead of a breakpoint instruction at each probepoint.
@@ -271,8 +271,6 @@ tweak the kernel's execution path, you need to suppress optimization,
271using one of the following techniques: 271using one of the following techniques:
272- Specify an empty function for the kprobe's post_handler or break_handler. 272- Specify an empty function for the kprobe's post_handler or break_handler.
273 or 273 or
274- Config CONFIG_OPTPROBES=n.
275 or
276- Execute 'sysctl -w debug.kprobes_optimization=n' 274- Execute 'sysctl -w debug.kprobes_optimization=n'
277 275
2782. Architectures Supported 2762. Architectures Supported
@@ -307,10 +305,6 @@ it useful to "Compile the kernel with debug info" (CONFIG_DEBUG_INFO),
307so you can use "objdump -d -l vmlinux" to see the source-to-object 305so you can use "objdump -d -l vmlinux" to see the source-to-object
308code mapping. 306code mapping.
309 307
310If you want to reduce probing overhead, set "Kprobes jump optimization
311support" (CONFIG_OPTPROBES) to "y". You can find this option under the
312"Kprobes" line.
313
3144. API Reference 3084. API Reference
315 309
316The Kprobes API includes a "register" function and an "unregister" 310The 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
40 $stack : Fetch stack address. 40 $stack : Fetch stack address.
41 $retval : Fetch return value.(*) 41 $retval : Fetch return value.(*)
42 +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) 42 +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
43 NAME=FETCHARG: Set NAME as the argument name of FETCHARG. 43 NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
44 FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
45 (u8/u16/u32/u64/s8/s16/s32/s64) are supported.
44 46
45 (*) only for return probe. 47 (*) only for return probe.
46 (**) this is useful for fetching a field of data structures. 48 (**) this is useful for fetching a field of data structures.