From 54ff5d7323e6b110e8796cdd412a39b7d13fb66d Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Wed, 26 Mar 2014 22:30:38 +0000 Subject: Add a SUBDIR_PARALLEL option to bsd.subdir.mk, to allow make to process all the SUBDIR entries in parallel, instead of serially. Apply this option to a selected number of Makefiles, which can greatly speed up the build on multi-core machines, when using make -j. This can be extended to more Makefiles later on, whenever they are verified to work correctly with parallel building. I tested this on a 24-core machine, with make -j48 buildworld (N = 6): before stddev after stddev ======= ====== ======= ====== real time 1741.1 16.5 959.8 2.7 user time 12468.7 16.4 14393.0 16.8 sys time 1825.0 54.8 2110.6 22.8 (user+sys)/real 8.2 17.1 E.g. the build was approximately 45% faster in real time. On machines with less cores, or with lower -j settings, the speedup will not be as impressive. But at least you can now almost max out a machine with buildworld! Submitted by: jilles MFC after: 2 weeks --- bin/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'bin/Makefile') diff --git a/bin/Makefile b/bin/Makefile index e4bc281db6383..63d96fedbdfe2 100644 --- a/bin/Makefile +++ b/bin/Makefile @@ -60,4 +60,6 @@ SUBDIR+= tests SUBDIR:= ${SUBDIR:O} +SUBDIR_PARALLEL= + .include -- cgit v1.3