diff options
| -rw-r--r-- | doc/manual/command-ref/conf-file.xml | 6 | ||||
| -rw-r--r-- | doc/manual/command-ref/opt-common.xml | 5 | ||||
| -rw-r--r-- | src/libmain/shared.cc | 5 | ||||
| -rw-r--r-- | src/libstore/globals.cc | 9 |
4 files changed, 18 insertions, 7 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 diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index 53fa83fe0dee..326202d295fb 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -167,6 +167,10 @@ struct LegacyArgs : public MixCommonArgs settings.set("build-fallback", "true"); }); + mkFlag1('j', "max-jobs", "jobs", "maximum number of parallel builds", [=](std::string s) { + settings.set("build-max-jobs", s); + }); + auto intSettingAlias = [&](char shortName, const std::string & longName, const std::string & description, const std::string & dest) { mkFlag<unsigned int>(shortName, longName, description, [=](unsigned int n) { @@ -174,7 +178,6 @@ struct LegacyArgs : public MixCommonArgs }); }; - intSettingAlias('j', "max-jobs", "maximum number of parallel builds", "build-max-jobs"); intSettingAlias(0, "cores", "maximum number of CPU cores to use inside a build", "build-cores"); intSettingAlias(0, "max-silent-time", "number of seconds of silence before a build is killed", "build-max-silent-time"); intSettingAlias(0, "timeout", "number of seconds before a build is killed", "build-timeout"); diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc index 12e2a3cf43dd..07af629260af 100644 --- a/src/libstore/globals.cc +++ b/src/libstore/globals.cc @@ -147,7 +147,14 @@ int Settings::get(const string & name, int def) void Settings::update() { _get(tryFallback, "build-fallback"); - _get(maxBuildJobs, "build-max-jobs"); + + auto s = get("build-max-jobs", std::string("1")); + if (s == "auto") + maxBuildJobs = std::max(1U, std::thread::hardware_concurrency()); + else + if (!string2Int(s, maxBuildJobs)) + throw Error("configuration setting ‘build-max-jobs’ should be ‘auto’ or an integer"); + _get(buildCores, "build-cores"); _get(thisSystem, "system"); _get(maxSilentTime, "build-max-silent-time"); |