[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20160831100118.71240562ebdbcf03bbb70f61@kernel.org>
Date: Wed, 31 Aug 2016 10:01:18 +0900
From: Masami Hiramatsu <mhiramat@...nel.org>
To: Masami Hiramatsu <mhiramat@...nel.org>,
Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: linux-kernel@...r.kernel.org,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>, Jiri Olsa <jolsa@...hat.com>
Subject: Re: [PATCH v2 0/3] perf probe: Introduce remote cross-arch probes
ping?
On Fri, 26 Aug 2016 01:24:10 +0900
Masami Hiramatsu <mhiramat@...nel.org> wrote:
> Hi,
>
> Here is the 2nd version of remote cross-arch probe support on perf-probe.
> V1 is here:
> https://lkml.org/lkml/2016/8/24/29
>
> Currently perf-probe doesn't supoort cross/remote target. This means
> we have to cross-build the perf-tools including libraries (elfutils,
> libelf etc.), and to prepare vmlinux with debuginfo which can be
> accessed from the target machine.
> This requires too much resource for a small embededd device.
>
> If we can analyze the debuginfo by perf-probe on host machine,
> we do not need to cross-build perf-tools, nor copy vmlinux on the
> device. :)
>
> For that purpose, this series adds --definition(-D) command for
> perf-probe, which shows trace event definition instead of adding
> it in running kernel, according to Arnaldo's comment.
> Using -D with --vmlinux(or -k)=OFFLINE-VMLINUX, perf-probe reads
> the vmlinux architecture and show definition with correct
> dwarf-registers.
>
> perf probe -k <cross-vmlinux> -D <probe-point> <arguments>
>
> Here is an example:
> -----
> $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
> p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
> -----
> Here, we can get probe/do_sys_open event by "copy & paste" the
> definition to target-machine's debugfs/tracing/kprobe_events.
>
> Note that it shows definition with direct symbol name instead of
> _text+offset. It is treated as an offline module.
>
> Thanks,
> ---
>
> Masami Hiramatsu (3):
> perf-probe: Show trace event definition
> perf-probe: Ignore vmlinux buildid if offline kernel is given
> perf-probe: Support probing on offline cross-arch binary
>
>
> tools/perf/Documentation/perf-probe.txt | 9 +++
> tools/perf/arch/arm/include/dwarf-regs-table.h | 9 +++
> tools/perf/arch/arm64/include/dwarf-regs-table.h | 13 +++++
> tools/perf/arch/powerpc/include/dwarf-regs-table.h | 27 ++++++++++
> tools/perf/arch/s390/include/dwarf-regs-table.h | 8 +++
> tools/perf/arch/sh/include/dwarf-regs-table.h | 25 +++++++++
> tools/perf/arch/sparc/include/dwarf-regs-table.h | 18 +++++++
> tools/perf/arch/x86/include/dwarf-regs-table.h | 14 +++++
> tools/perf/arch/xtensa/include/dwarf-regs-table.h | 8 +++
> tools/perf/builtin-probe.c | 34 ++++++++++--
> tools/perf/util/Build | 1
> tools/perf/util/dwarf-regs.c | 55 ++++++++++++++++++++
> tools/perf/util/include/dwarf-regs.h | 6 ++
> tools/perf/util/probe-event.c | 50 ++++++++++++++++++
> tools/perf/util/probe-event.h | 1
> tools/perf/util/probe-finder.c | 27 ++++++----
> tools/perf/util/probe-finder.h | 1
> tools/perf/util/symbol-elf.c | 2 -
> 18 files changed, 289 insertions(+), 19 deletions(-)
> create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
> create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
> create mode 100644 tools/perf/util/dwarf-regs.c
>
> --
> Masami Hiramatsu (Linaro Ltd.) <mhiramat@...nel.org>
--
Masami Hiramatsu <mhiramat@...nel.org>
Powered by blists - more mailing lists