Commit c7a14fdc authored by Frank Ch. Eigler's avatar Frank Ch. Eigler Committed by Arnaldo Carvalho de Melo
Browse files

perf build-ids: Fall back to debuginfod query if debuginfo not found 

During a perf-record, use the -ldebuginfod API to query a debuginfod
server, should the debug data not be found in the usual system
locations.  If successful, the usual $HOME/.debug dir is populated.

Tested with:

  $ find .
  .
  ./ctags-debuginfo-5.8-26.fc31.x86_64.rpm
  ./usr
  ./usr/lib
  ./usr/lib/debug
  ./usr/lib/debug/.build-id
  ./usr/lib/debug/.build-id/ca
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d.debug
  ./usr/lib/debug/usr
  ./usr/lib/debug/usr/bin
  ./usr/lib/debug/usr/bin/ctags-5.8-26.fc31.x86_64.debug

  $ debuginfod  -F .
  ...

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.107 MB perf.data (1483 samples) ]

  $ find ~/.debug | grep ctags
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ DEBUGINFOD_URLS=http://localhost:8002

 perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.108 MB perf.data (1531 samples) ]

  $ find ~/.debug | grep ctag
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/debug
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

Note the 'debug' file is created in the last run.

Note that currently the debuginfo data are downloaded only on record path,
we still need add this support to perf build-id/report.. and test ;-)

Tested-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarFrank Ch. Eigler <fche@redhat.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a508d061

tools/build/Makefile.feature

+2 −1
Original line number Diff line number Diff line
@@ -98,7 +98,8 @@ FEATURE_TESTS_EXTRA := \ 
         llvm-version                   \

         clang                          \

         libbpf                         \

         libpfm4

         libpfm4                        \

         libdebuginfod



FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC)

tools/build/feature/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ FILES= \ 
         test-libelf-gelf_getnote.bin           \

         test-libelf-getshdrstrndx.bin          \

         test-libelf-mmap.bin                   \

         test-libdebuginfod.bin                 \

         test-libnuma.bin                       \

         test-numa_num_possible_cpus.bin        \

         test-libperl.bin                       \
@@ -157,6 +158,9 @@ $(OUTPUT)test-libelf-gelf_getnote.bin: 
$(OUTPUT)test-libelf-getshdrstrndx.bin:

	$(BUILD) -lelf



$(OUTPUT)test-libdebuginfod.bin:

	$(BUILD) -ldebuginfod



$(OUTPUT)test-libnuma.bin:

	$(BUILD) -lnuma

tools/build/feature/test-libdebuginfod.c

0 → 100644
+8 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <elfutils/debuginfod.h>



int main(void)

{

	debuginfod_client* c = debuginfod_begin();

	return (long)c;

}

tools/perf/Makefile.config

+8 −0
Original line number Diff line number Diff line
@@ -501,6 +501,14 @@ ifndef NO_LIBELF 
    CFLAGS += -DHAVE_ELF_GETSHDRSTRNDX_SUPPORT

  endif



  ifndef NO_LIBDEBUGINFOD

    $(call feature_check,libdebuginfod)

    ifeq ($(feature-libdebuginfod), 1)

      CFLAGS += -DHAVE_DEBUGINFOD_SUPPORT

      EXTLIBS += -ldebuginfod

    endif

  endif



  ifndef NO_DWARF

    ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)

      msg := $(warning DWARF register mappings have not been defined for architecture $(SRCARCH), DWARF support disabled);

tools/perf/Makefile.perf

+2 −0
Original line number Diff line number Diff line
@@ -124,6 +124,8 @@ include ../scripts/utilities.mak 
#

# Define LIBPFM4 to enable libpfm4 events extension.

#

# Define NO_LIBDEBUGINFOD if you do not want support debuginfod

#



# As per kernel Makefile, avoid funny character set dependencies

unexport LC_ALL

CRA Git | Maintained and supported by SUSTech CRA and CCSE