From db98116491dc338288aba5834349ef0ce378104b Mon Sep 17 00:00:00 2001
From: Darren Garvey <darren.garvey@gmail.com>
Date: Sat, 13 Jun 2015 12:14:55 +0100
Subject: [PATCH] Build with as many cores as there are on the system.

On unix-like systems where we can use /proc/cpuinfo to find the
number of cores, use all of them when building, rather than only
using 4.

Still default to 4 when we don't have /proc/cpuinfo. Apparently
you can use $(sysctl -a | grep machdep.cpu | grep thread_count)
on Mac, but I don't have one available to try.
---
 build.sh    | 5 ++++-
 build_ps.sh | 6 ++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/build.sh b/build.sh
index 2807db98..ebf4ce37 100755
--- a/build.sh
+++ b/build.sh
@@ -18,5 +18,8 @@ if [ ! -f config.mk ]; then
     cp make/config.mk config.mk
 fi
 
-make -j4
+# Use as many CPUs as the host has to build, or default to
+# 4 if we're not on a unix-y system.
+num_cpus=$(grep -sc ^processor /proc/cpuinfo || echo 4)
+make -j$num_cpus
 
diff --git a/build_ps.sh b/build_ps.sh
index b9e44b77..d0028b1e 100755
--- a/build_ps.sh
+++ b/build_ps.sh
@@ -28,5 +28,7 @@ fi
 sed -i 's/USE_DIST_PS.*/USE_DIST_PS = 1/' config.mk
 sed -i 's/PS_PATH.*/PS_PATH = .\/ps-lite/' config.mk
 
-make -j4
-# make $1
+# Use as many CPUs as the host has to build, or default to
+# 4 if we're not on a unix-y system.
+num_cpus=$(grep -sc ^processor /proc/cpuinfo || echo 4)
+make -j$num_cpus