Messages in this thread | | | From | Masami Hiramatsu <> | Subject | [PATCH tracing/kprobes v3 0/7] tracing/kprobes, perf: perf probe support take 3 | Date | Wed, 07 Oct 2009 18:27:33 -0400 |
| |
Hi,
These patches introduce 'perf probe' command and update kprobe-tracer. perf probe command allows you to add new probe points by C line number and local variable names.
This version fixes some bugs, remove -r option (because perf always be used for online kernel) and rename kprobe-tracer special vars.
Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...]
-k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.)
Examples -------- 1) Add a new kprobe probe on a line of C source code. ./perf probe -P 'p:myprobe @fs/read_write.c:285 file buf count' Adding new event: p:myprobe vfs_read+57 file=%bx buf=%si count=%ax
2) Add a new kretprobe probe on a function return. ./perf probe -P 'r:myretprobe vfs_read $retval' Adding new event: r:myretprobe vfs_read+0 $retval
3) Check it in the perf list. ./perf list ... rNNN [raw hardware event descriptor]
kprobes:myprobe [Tracepoint event] kprobes:myretprobe [Tracepoint event] skb:kfree_skb [Tracepoint event] ...
4) Record the event by perf ./perf record -f -e kprobes:myprobe:record -F 1 -a ls ... [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.081 MB perf.data (~3540 samples) ]
5) Trace the event ./perf trace perf-11445 [000] 95862.048894383: myprobe: (c04bbed5) file=dae15e80 buf=b78b2000 count=400 perf-11445 [000] 95862.049066533: myprobe: (c04bbed5) file=dae15d80 buf=b78b2000 count=400 perf-11445 [000] 95862.049134394: myprobe: (c04bbed5) file=dae15d80 buf=b78b2000 count=400 perf-11445 [000] 95862.049171495: myprobe: (c04bbed5) file=dae15a80 buf=b78b2000 count=400
NOTE ---- perf still fails to parse format if arguments have special charactors (e.g. $retval, +16($stack) etc.) So, tracing myretprobe will fail with this version. This will be solved by naming arguments automatically if it doesn't have C-language name.
TODO ---- - Support sys_perf_counter_open (non-root) - Input from stdin/output to stdout - 64-bits return value on x86-32 - Static variable - Fields of data structures (var->field) - Type support - Bit fields - Array (var[N]) - Dynamic array indexing (var[var2]) - String/dynamic arrays (var:string, var[N..M]) - Force Type casting ((type)var) - Non-inline search - libdw, libdwfl - etc.
Thank you,
---
Masami Hiramatsu (7): perf: perf probe command supports without libdwarf perf: Add perf probe subcommand for kprobe-event setup helper tracing/kprobes: Rename fixed field name tracing/kprobes: Avoid field name confliction tracing/kprobes: Rename special variables tracing/kprobes: Remove '$ra' special variable tracing/kprobes: Add $ prefix to special variables
Documentation/trace/kprobetrace.txt | 27 + kernel/trace/trace_kprobe.c | 158 +++++--- tools/perf/Makefile | 10 + tools/perf/builtin-probe.c | 385 ++++++++++++++++++++ tools/perf/builtin.h | 1 tools/perf/perf.c | 1 tools/perf/util/probe-finder.c | 690 +++++++++++++++++++++++++++++++++++ tools/perf/util/probe-finder.h | 70 ++++ 8 files changed, 1269 insertions(+), 73 deletions(-) create mode 100644 tools/perf/builtin-probe.c create mode 100644 tools/perf/util/probe-finder.c create mode 100644 tools/perf/util/probe-finder.h
-- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
| |