diff options
Diffstat (limited to 'HOWTO/INSTALL.md')
| -rw-r--r-- | HOWTO/INSTALL.md | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/HOWTO/INSTALL.md b/HOWTO/INSTALL.md index 5b3a09df2b..53b1b8cd8a 100644 --- a/HOWTO/INSTALL.md +++ b/HOWTO/INSTALL.md @@ -385,7 +385,7 @@ Some of the available `configure` options are: * `--enable-static-{nifs,drivers}` - To allow usage of nifs and drivers on OSs that do not support dynamic linking of libraries it is possible to statically link nifs and drivers with the main Erlang VM binary. This is done by passing - a comma seperated list to the archives that you want to statically link. e.g. + a comma separated list to the archives that you want to statically link. e.g. `--enable-static-nifs=/home/$USER/my_nif.a`. The path has to be absolute and the name of the archive has to be the same as the module, i.e. `my_nif` in the example above. This is also true for drivers, but then it is the driver name @@ -409,6 +409,30 @@ Some of the available `configure` options are: If you or your system has special requirements please read the `Makefile` for additional configuration information. +#### Atomic Memory Operations and the VM #### + +The VM with SMP support makes quite a heavy use of atomic memory operations. +An implementation providing native atomic memory operations is therefore very +important when building Erlang/OTP. By default the VM will refuse to build +if native atomic memory operations are not available. + +Erlang/OTP itself provides implementations of native atomic memory operations +that can be used when compiling with a `gcc` compatible compiler on 32-bit +and 64-bit x86, 32-bit and 64-bit SPARC V9, and 32-bit PowerPC. When compiling +with a `gcc` compatible compiler on other architectures, the VM may be able to +make use of native atomic operations using the `__sync_*` primitives, but this +should only be used as a last resort since this wont give you optimal +performance. When compiling on Windows using a MicroSoft Visual C++ compiler +native atomic memory operations are provided by Windows APIs. + +You are recommended to use the native atomic implementation provided by +Erlang/OTP, or the API provided by Windows. If these do not provide native +atomics on your platform, you are recommended to build and install +[libatomic_ops][] before building Erlang/OTP. The `libatomic_ops` library +provides native atomic memory operations for a variety of platforms and +compilers. When building Erlang/OTP you need to inform the build system of +where the `libatomic_ops` library is installed using the +`--with-libatomic_ops=PATH` configure switch. ### Building ### @@ -862,3 +886,4 @@ under the License. [Optional Utilities]: #Optional-Utilities [Building on a Mac]: #Advanced-configuration-and-build-of-ErlangOTP_Building_OS-X-Darwin [Building with wxErlang]: #Advanced-configuration-and-build-of-ErlangOTP_Building_Building-with-wxErlang + [libatomic_ops]: https://github.com/ivmai/libatomic_ops/ |