lkml.org 
[lkml]   [2018]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC 0/6] perf probe: Attempt to improve C++ probing
    Hi Holger,

    Thank you for your great work!

    On Mon, 14 May 2018 12:19:34 +0800
    Holger Freyther <automatic+kernel@freyther.de> wrote:

    > From: Holger Hans Peter Freyther <holgar+kernel@google.com>
    >
    > Currently perf probe -x app --funcs will list and demangle C++ functions
    > but the other probe actions can't work with them. When asking probe to not
    > demangle it will not list any of the application symbols creating the
    > impression that there are no symbols at all.
    >
    > Make --funcs --no-demangle list all C++ functions and modify the handling
    > for listing code, variables and adding the uprobe work with the demangled
    > C++ function name.
    >
    > I tried to keep this as minimal as possible but having to keep the dso in
    > the debuginfo and passing it everywhere to be able to demangle the linkage
    > name isn't pretty (and for C++ demangling the struct dso is not of much
    > use. Maybe having a static "empty" dso could avoid a lot of the changes).
    >
    > Maybe the easiest first patch is to default to --no-demangle and change
    > the DEFAULT_FUNC_FILTER to not include mangled C++ symbols. The remaining
    > tooling would work then.
    >
    > This has seen very little testing outside the following commands.
    >
    > My test set includes:
    >
    > ./perf probe -x . -L "std::vector<int, std::allocator<int> >::at"
    > ./perf probe -x . -L "std::vector<int, std::allocator<int> >::at:2-3"
    >
    > ./perf probe -x . -V "std::vector<int, std::allocator<int> >::at"
    > ./perf probe -x . -V "std::vector<int, std::allocator<int> >::at:2"
    > ./perf probe -x . -V "std::vector<int, std::allocator<int> >::size%return"

    OK, let me review it.

    >
    >
    > Holger Hans Peter Freyther (6):
    > perf probe: Do not exclude mangled C++ funcs
    > perf probe: Parse linerange for C++ functions
    > perf probe: Make listing of C++ functions work
    > perf probe: Show variables for C++ functions
    > perf probe: Make listing of variables work for C++ functions
    > perf probe: Make it possible to add a C++ uprobe
    >
    > tools/perf/builtin-probe.c | 2 +-
    > tools/perf/util/probe-event.c | 77 ++++++++++++++++++++-
    > tools/perf/util/probe-finder.c | 152 ++++++++++++++++++++++++++++++-----------
    > tools/perf/util/probe-finder.h | 3 +
    > tools/perf/util/string.c | 57 ++++++++++++++++
    > tools/perf/util/string2.h | 1 +
    > 6 files changed, 247 insertions(+), 45 deletions(-)
    >
    > --
    > 2.7.4
    >


    --
    Masami Hiramatsu <mhiramat@kernel.org>

    \
     
     \ /
      Last update: 2018-05-14 15:08    [W:4.751 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site