Commit 2cfbe880 authored Oct 02, 2013 by Ingo Molnar

tools/perf/build: Automatically build in parallel, based on number of CPUs in the system

Implement automatic parallel builds when building in tools/perf:

  $ time make

  # [ perf build: Doing 'make -j12' parallel build. ]

  Auto-detecting system features:

  ...

  real    0m9.265s
  user    0m59.888s
  sys     0m6.082s

On GNU make achieving this is not particularly easy, it requires a separate
makefile, which then invokes the main Makefile.

( Note: this patch adds Makefile.parallel to show the concept - the two
  makefiles will be flipped in the next patch to avoid having to specify -f
  to get parallelism in the default build. )

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-dvBjwqiTyzrufzkz8oanhpf9@git.kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent b3b64a12

tools/perf/Makefile.parallel

0 → 100644

+26 −0

Original line number	Diff line number	Diff line
		#
		# Do a parallel build with multiple jobs, based on the number of CPUs online
		# in this system: 'make -j8' on a 8-CPU system, etc.
		#
		# (To override it, run 'make JOBS=1' and similar.)
		#
		ifeq ($(JOBS),)
		JOBS := $(shell grep -c ^processor /proc/cpuinfo 2>/dev/null)
		ifeq ($(JOBS),)
		JOBS := 1
		endif
		endif

		export JOBS

		$(info $(shell printf '# [ perf build: Doing '\''make \033[33m-j'$(JOBS)'\033[m'\'' parallel build. ]\n'))

		#
		# Needed if no target specified:
		#
		all:
		@$(MAKE) --no-print-directory -j$(JOBS) $@

		%:
		@$(MAKE) --no-print-directory -j$(JOBS) $@

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