mirror/buildroot
1
0
Fork 0
mirror of https://gitlab.com/buildroot.org/buildroot.git synced 2026-08-08 08:30:47 -09:00
Code Issues Packages Projects Releases Wiki Activity

package/linux-tools: perf: build with libtraceevent support when it is selected

Browse Source 
When trying to perform a custom uprobe recording on a target with perf
built by buildroot, the recording step fails as perf can not record
uprobes without libtraceevent support:

  $ perf probe -x linked_list insert_name index
  Target program is compiled without optimization. Skipping prologue.
  Probe on address 0x808 to force probing at the function entry.

  Added new event:
    probe_linked_list:insert_name (on insert_name in /root/gdb/linked_list with index)

  perf is not linked with libtraceevent, to use the new probe you can use tracefs:

          cd /sys/kernel/tracing/
          echo 1 > events/probe_linked_list/insert_name/enable
          echo 1 > tracing_on
          cat trace_pipe
          Before removing the probe, echo 0 > events/probe_linked_list/insert_name/enable
  $ perf record -e probe_linked_list:insert_name ./linked_list
  event syntax error: 'probe_linked_list:insert_name'
                       \___ unsupported tracepoint

  libtraceevent is necessary for tracepoint support
  Run 'perf list' for a list of valid events

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -e, --event <event>   event selector. use 'perf list' to list available events

libtraceevent support for perf has been disabled with commit
b4ab45a5c1 ("package/linux-tools: disable libtracevent detection")
because there was no libtraceevent package in buildroot to replace the
former libtraceevent removed from the kernel sources. Since then, commit
1474f1b34b ("package/libtraceevent: new package") has introduced a
libtraceevent package. We can then expose again the possibility to build
perf with libtraceevent support.

Make buildroot perf makefile detect if libtraceevent package has been
enabled, and if so, allow to build perf with libtraceevent support.

Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
This commit is contained in:
Alexis Lothoré
2025-07-09 17:04:14 +02:00
committed by Julien Olivain
parent 9824b964a7
commit 5396f730d7
1 changed files with 6 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
package/linux-tools/linux-tool-perf.mk.in
View File

@@ -28,7 +28,6 @@ PERF_MAKE_FLAGS = \
NO_LIBPERL=1 \
NO_LIBPYTHON=1 \
NO_LIBBIONIC=1 \
NO_LIBTRACEEVENT=1 \
NO_SHELLCHECK=1
# We need to pass an argument to ld for setting the emulation when
@@ -128,6 +127,12 @@ PERF_MAKE_FLAGS += CORESIGHT=1
# bare "ifdef CORESIGHT" constructs.
endif
ifeq ($(BR2_PACKAGE_LIBTRACEEVENT),y)
PERF_DEPENDENCIES += libtraceevent
else
PERF_MAKE_FLAGS += NO_LIBTRACEEVENT=1
endif
# We really do not want to build the perf documentation, because it
# has stringent requirement on the documentation generation tools,
# like xmlto and asciidoc), which may be lagging behind on some