Patch "perf build: Fix traceevent plugins build race" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    perf build: Fix traceevent plugins build race

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-build-fix-traceevent-plugins-build-race.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 67befc652845c8ffbefc8d173a6e6ced14d472f1 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@kernel.org>
Date: Thu, 26 Nov 2015 14:54:04 +0100
Subject: perf build: Fix traceevent plugins build race

From: Jiri Olsa <jolsa@kernel.org>

commit 67befc652845c8ffbefc8d173a6e6ced14d472f1 upstream.

Ingo reported following build failure:

  $ make clean install
  ...
    CC       plugin_kmem.o
  fixdep: error opening depfile: ./.plugin_hrtimer.o.d: No such file or directory
  /home/mingo/tip/tools/build/Makefile.build:77: recipe for target
  'plugin_hrtimer.o' failed
  make[3]: *** [plugin_hrtimer.o] Error 2
  Makefile:189: recipe for target 'plugin_hrtimer-in.o' failed
  make[2]: *** [plugin_hrtimer-in.o] Error 2
  Makefile.perf:414: recipe for target 'libtraceevent_plugins' failed
  make[1]: *** [libtraceevent_plugins] Error 2
  make[1]: *** Waiting for unfinished jobs....

Currently we have the install-traceevent-plugins target being dependent
on $(LIBTRACEEVENT), which will actualy not build any plugin. So the
install-traceevent-plugins target itself will try to build plugins,
but..

Plugins built is also triggered by perf build itself via
libtraceevent_plugins target.

This might cause a race having one make thread removing temp files from
another and result in above error. Fixing this by having proper plugins
build dependency before installing plugins.

Reported-and-Tested-by:: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1448546044-28973-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/perf/Makefile.perf |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -420,7 +420,7 @@ $(LIBTRACEEVENT)-clean:
 	$(call QUIET_CLEAN, libtraceevent)
 	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) O=$(OUTPUT) clean >/dev/null
 
-install-traceevent-plugins: $(LIBTRACEEVENT)
+install-traceevent-plugins: libtraceevent_plugins
 	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) install_plugins
 
 $(LIBAPI): fixdep FORCE


Patches currently in stable-queue which might be from jolsa@kernel.org are

queue-4.4/perf-build-fix-traceevent-plugins-build-race.patch