How to install DLB

Build requirements

A supported platform running GNU/Linux (i386, x86-64, ARM, PowerPC, IA64, or RISC-V)
C compiler
Python 2.7 or higher (Python 3 recommended; required for some optional components)

Installation steps

Get the latest DLB tarball from https://pm.bsc.es/dlb-downloads:
```
tar xzf dlb-x.y.z.tar.gz
cd dlb-x.y.z/
```
Configure it, with optionally some of the DLB configure flags:
```
./configure --prefix=<dlb_install_path> [--with-mpi]
```
Build and install:
```
make [-j N]
make install
```

Other installation methods

Downloading from git repository

If DLB is downloaded from https://github.com/bsc-pm/dlb or other git repository, additional software is needed, such as autoconf, automake, and libtool. Once the project is downloaded, run bootstrap.sh to generate the appropriate build files. Then, follow the installation steps described above in steps 2 and 3.

Meson

DLB also offers the possibility to configure and build with Meson and Ninja. The current meson build script does not provide all the functionality of the autotools scripts, in particular documentation and examples are not yet integrated, but it is a great alternative for developers or quick installations as it significantly improves build and test times.

To set up a meson build, run:

meson setup <build_dir> -Dmpi=enabled -Dprefix=<dlb_install_path>
cd <build_dir>
ninja install

DLB configure flags

Debug and Instrumentation versions

By default, the autotools scripts will configure and build four variants of the library, the combination of the performance and debug variants with the instrumentation variant. The main library libdlb.so (performance, no-instrumentation) cannot be disabled but the other three can be freely disabled using the following flags.

--disable-debug: Disable Debug variant library; otherwise installed as libdlb_dbg.so.
--disable-instrumentation: Disable Instrumentation variant library; otherwise installed as libdlb_instr.so.
--disable-instrumentation-debug: Disable Instrumentation-Debug variant library; otherwise installed as libdlb_instr_dbg.so.

Optional dependencies

MPI allows LeWI to automatically detect some patterns about the load balance of the application, and TALP to gather MPI metrics. When MPI support is detected, another set of libraries with prefix libdlb_mpi* are built; refer to Preload mechanism for MPI applications for more details.

--with-mpi=<mpi_prefix>: Specify where to find the MPI libraries and include files.

HWLOC allows DLB library to get some knowledge about the hardware details of the compute node. If HWLOC is not found, hardware detection will fall back to some OS utilities.

--with-hwloc=<hwloc_prefix>: Specify where to find the HWLOC libraries.

PAPI allows DLB to collect hardware counters. If PAPI is found TALP will also measure the IPC of the instrumented regions.

--with-papi=<papi_prefix>: Specify where to find the PAPI libraries.

CUPTI libraries from CUDA allow TALP to obtain performance metrics from NVIDIA GPUs.

--with-cuda=<cuda_prefix>: Specify where to find CUDA and CUPTI libraries.

ROCm may provide support for rocprofilerv2 (now deprecated and only half functional with DLB) and for the rocprofiler-sdk (available starting with ROCm 6.2; recommended). These libraries enable TALP to collect performance metrics from AMD GPUs.

--with-rocm=<rocm_prefix>: Specify where to find ROCm profiling libraries.

Additional MPI configure flags

The DLB MPI library libdlb_mpi.so defines, and thus may intercept, both C and Fortran MPI symbols. In some systems, having both symbols together may suppose a problem. If needed, DLB can be configured to generate additional libraries with only either C or Fortran MPI symbols.

--enable-c-mpi-library: Compile also a DLB MPI library specific for C, installed as libdlb_mpic.so.
--enable-fortran-mpi-library: Compile also a DLB MPI library specific for Fortran, installed as libdlb_mpif.so.

DLB will compile by default the MPI Fortran 2008 MPI bindings if a suitable Fortran compiler is found and the MPI library supports them. These bindings are needed to intercept such MPI F08 calls. However, if the compilation failed for some reason, the bindings may be explicitly disabled.

--disable-mpi-f08-bindings: Disable MPI Fortran 2008 bindings
--disable-mpi-f08ts-bindings: Disable MPI Fortran 2008 + TS 29113 bindings