From de4cdd0d47adc70a4db12397a42c18ee50b4e662 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 2 May 2014 12:51:43 +0200
Subject: [PATCH] Set build-max-jobs to the number of available cores by
 default

More zero configuration.
---
 src/libstore/globals.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index c359367bba..739199d48e 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -5,6 +5,7 @@
 
 #include <map>
 #include <algorithm>
+#include <unistd.h>
 
 
 namespace nix {
@@ -29,6 +30,10 @@ Settings::Settings()
     buildVerbosity = lvlError;
     maxBuildJobs = 1;
     buildCores = 1;
+#ifdef _SC_NPROCESSORS_ONLN
+    long res = sysconf(_SC_NPROCESSORS_ONLN);
+    if (res > 0) buildCores = res;
+#endif
     readOnlyMode = false;
     thisSystem = SYSTEM;
     maxSilentTime = 0;