[PATCH 38/50] tools/perf/build: Automatically build in parallel, based on number of CPUs in the system

From: Ingo Molnar
Date: Mon Oct 07 2013 - 08:02:11 EST


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@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-dvBjwqiTyzrufzkz8oanhpf9@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
tools/perf/Makefile.parallel | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/tools/perf/Makefile.parallel b/tools/perf/Makefile.parallel
new file mode 100644
index 0000000..ec5e08b
--- /dev/null
+++ b/tools/perf/Makefile.parallel
@@ -0,0 +1,26 @@
+#
+# 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) $@
+
--
1.7.11.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/