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authorEelco Dolstra <edolstra@gmail.com>2017-02-28T11·54+0100
committerEelco Dolstra <edolstra@gmail.com>2017-02-28T11·54+0100
commit7251d048fa812d2551b7003bc9f13a8f5d4c95a5 (patch)
tree242d94f45d24a2becf373cdda7e34f3128111982 /doc/manual/command-ref
parent3fab1f04a7d9a5d8ca0f7faf071d5767f93c7e22 (diff)
Support auto-configuration of build-max-jobs
"build-max-jobs" and the "-j" option can now be set to "auto" to use
the number of CPUs in the system. (Unlike build-cores, it doesn't use
0 to imply auto-configuration, because a) magic values are a bad idea
in general; b) 0 is a legitimate value used to disable local
building.)

Fixes #1198.
Diffstat (limited to 'doc/manual/command-ref')
-rw-r--r--doc/manual/command-ref/conf-file.xml6
-rw-r--r--doc/manual/command-ref/opt-common.xml5
2 files changed, 6 insertions, 5 deletions
diff --git a/doc/manual/command-ref/conf-file.xml b/doc/manual/command-ref/conf-file.xml
index 0f7a2deba049..96f8a4b608a4 100644
--- a/doc/manual/command-ref/conf-file.xml
+++ b/doc/manual/command-ref/conf-file.xml
@@ -101,9 +101,9 @@ flag, e.g. <literal>--option gc-keep-outputs false</literal>.</para>
 
     <listitem><para>This option defines the maximum number of jobs
     that Nix will try to build in parallel.  The default is
-    <literal>1</literal>.  You should generally set it to the number
-    of CPUs in your system (e.g., <literal>2</literal> on an Athlon 64
-    X2).  It can be overridden using the <option
+    <literal>1</literal>. The special value <literal>auto</literal>
+    causes Nix to use the number of CPUs in your system.  It can be
+    overridden using the <option
     linkend='opt-max-jobs'>--max-jobs</option> (<option>-j</option>)
     command line switch.</para></listitem>
 
diff --git a/doc/manual/command-ref/opt-common.xml b/doc/manual/command-ref/opt-common.xml
index 2a076877a1b4..2aa41c4d4389 100644
--- a/doc/manual/command-ref/opt-common.xml
+++ b/doc/manual/command-ref/opt-common.xml
@@ -93,8 +93,9 @@
   <term><option>-j</option></term>
 
   <listitem><para>Sets the maximum number of build jobs that Nix will
-  perform in parallel to the specified number.  The default is
-  specified by the <link
+  perform in parallel to the specified number.  Specify
+  <literal>auto</literal> to use the number of CPUs in the system.
+  The default is specified by the <link
   linkend='conf-build-max-jobs'><literal>build-max-jobs</literal></link>
   configuration setting, which itself defaults to
   <literal>1</literal>.  A higher value is useful on SMP systems or to