nvml: Non-Volatile Memory Library

This is the top-level README.md of the NVM Library. For more information, see http://pmem.io.

The Libraries

Please see the file LICENSE for information on how this library is licensed.

This tree contains a collection of libraries for using Non-Volatile Memory (NVM). There are currently eight libraries:

• libpmem -- basic pmem operations like flushing
• libpmemblk, libpmemlog, libpmemobj -- pmem transactions
• libvmem, libvmmalloc¹ -- volatile use of pmem
• libpmempool -- persistent memory pool management
• librpmem¹ -- remote access to persistent memory (EXPERIMENTAL)

and one command-line utility:

• pmempool -- standalone tool for off-line pool management

These libraries and utilities are described in more detail on the pmem web site. There you'll find man pages, examples, and tutorials.

Currently, these libraries only work on 64-bit Linux, Windows² and 64-bit FreeBSD 11+³.

¹ Not supported on Windows.

² NVML for Windows is feature complete, but not yet considered production quality.

³ DAX and libfabric are not yet supported in FreeBSD, so at this time NVML is available as a technical preview release for development purposes.

Pre-Built Packages

If you want to install these libraries to try them out of your system, you can either install pre-built packages, which we build for every stable release, or clone the tree and build it yourself.

Builds are tagged something like 0.2+b1, which means Build 1 on top of version 0.2 and 0.2-rc3, which means Release Candidate 3 for version 0.2. Stable releases are the simpler major.minor tags like 0.2. To find pre-build packages, check the Downloads associated with the stable releases on the github release page.

Building The Source

The source tree is organized as follows:

• doc -- man pages describing each library contained here
• src -- the source for the libraries
• src/include -- public header files for all the libraries
• src/benchmarks -- benchmarks used by development team
• src/examples -- brief example programs using these libraries
• src/freebsd -- FreeBSD-specific header files
• src/test -- unit tests used by development team
• src/tools -- various tools developed for NVML
• src/windows -- Windows-specific source and header files
• utils -- utilities used during build & test
• CONTRIBUTING.md -- instructions for people wishing to contribute
• CODING_STYLE.md -- coding standard and conventions for NVML

To build this library on Linux, you may need to install the following required packages on the build system:

• autoconf
• pkg-config

On Windows, to build NVML and run the tests you need:

• MS Visual Studio 2015
• Windows SDK 10.0.14393 (or later)
• perl (i.e. ActivePerl)
• PowerShell 5

To build and test this library on FreeBSD, you may need to install the following required packages on the build system:

• autoconf
• bash
• binutils
• coreutils
• e2fsprogs-libuuid
• gmake
• libunwind
• ncurses⁴
• pkgconf

Some tests and example applications require additional packages, but they do not interrupt building if they are missing. An appropriate message is displayed instead. For details please read the DEPENDENCIES section in the appropriate README file.

See our Dockerfiles to get an idea what packages are required to build on the Travis-CI system.

⁴ The pkg version of ncurses is required for proper operation; the base version included in FreeBSD is not sufficient.

Building NVML on Linux or FreeBSD

To build the latest development version, just clone this tree and build the master branch:

	$ git clone https://github.com/pmem/nvml
	$ cd nvml

Once the build system is setup, the NVM Library is built using the make⁵ command at the top level:

	$ make

If you want to compile, and hopefully run the builtin tests, with a different compiler, you have to provide the CC and CXX variables. For example:

	$ make CC=clang CXX=clang++

These variables are independent and setting CC=clang does not set CXX=clang++.

Once the make completes,⁶ all the libraries are built and the examples under src/examples are built as well. You can play with the library within the build tree, or install it locally on your machine. Installing the library is more convenient since it installs man pages and libraries in the standard system locations:

	(as root...)
	# make install

To install this library into other locations, you can use the prefix variable, e.g.:

	$ make install prefix=/usr/local

This will install files to /usr/local/lib, /usr/local/include /usr/local/share/man.

To prepare this library for packaging, you can use the DESTDIR variable, e.g.:

	$ make install DESTDIR=/tmp

This will install files to /tmp/usr/lib, /tmp/usr/include /tmp/usr/share/man.

The man pages (groff files) are generated as part of the install rule. To generate the documentation separately, run:

	$ make doc

DEPENDENCIES: doxygen, graphviz, pandoc⁷

To install a complete copy of the source tree to $(DESTDIR)/nvml:

	$ make source DESTDIR=some_path

To build rpm packages on rpm-based distributions:

	$ make rpm

If you want to build packages without running tests, run:

	$ make BUILD_PACKAGE_CHECK=n rpm

DEPENDENCIES: rpmbuild

To build dpkg packages on Debian-based distributions:

	$ make dpkg

If you want to build packages without running tests, run:

	$ make BUILD_PACKAGE_CHECK=n dpkg

DEPENDENCIES: devscripts

⁵ For FreeBSD, use gmake rather than make.

⁶ By default all code is built with the -Werror flag, which fails the whole build when the compiler emits any warning. This is very useful during development, but can be annoying in deployment. If you want to disable -Werror, use the EXTRA_CFLAGS variable:

	$ make EXTRA_CFLAGS="-Wno-error"

or

	$ make EXTRA_CFLAGS="-Wno-error=$(type-of-warning)"

⁷Pandoc is provided by the hs-pandoc package on FreeBSD.

Testing the Libraries

Before running the tests, you may need to prepare a test configuration file (src/test/testconfig.sh). Please see the available configuration settings in the example file (src/test/testconfig.sh.example).

To build and run the unit tests:

	$ make check

To run a specific subset of tests, run for example:

	$ make check TEST_TYPE=short TEST_BUILD=debug TEST_FS=pmem

To modify the timeout which is available for check type tests, run:

	$ make check TEST_TIME=1m

This will set the timeout to 1 minute.

Please refer to the src/test/README for more details on how to run different types of tests.

The libraries support standard Valgrind drd, helgrind and memcheck, as well as a PM-aware version of Valgrind⁸. To test the libraries with Valgrind, supply the compiler with the USE_VG_<TOOL> flag, for example:

	$ make EXTRA_CFLAGS=-DUSE_VG_MEMCHECK

The USE_VALGRIND flag enables all Valgrind tools (drd, helgrind, memcheck and pmemcheck).⁸

The SANITIZE flag allows the libraries to be tested with various sanitizers. For example, to test the libraries with AddressSanitizer and UndefinedBehaviorSanitizer, run:

	$ make SANITIZE=address,undefined clobber check

If you wish to run C++ standard library containers tests, you need to set the path to your custom versions of either gcc or libc++. For gcc run:

	$ make USE_CUSTOM_GCC=1 GCC_INCDIR=/path/to/includes GCC_LIBDIR=/path/to/lib check

If you want to use a custom version of libc++ run:

	$ make USE_LLVM_LIBCPP=1 LIBCPP_INCDIR=/path/to/includes/ LIBCPP_LIBDIR=/path/to/lib check

Please remember to set the appropriate versions of CC/CXX when using custom versions of the library.

For example, when using a custom version of libc++(version 3.9) installed to /usr/local/libcxx, to execute the tests run:

	$ CC=clang CXX=clang++ make USE_LLVM_LIBCPP=1 LIBCPP_INCDIR=/usr/local/libcxx/include/c++/v1 LIBCPP_LIBDIR=/usr/local/libcxx/lib check

⁸ PM-aware Valgrind is not yet available for FreeBSD. Until it is, USE_VALGRIND is not supported and the individual USE_VG_<TOOL> options must be used instead.

⁹ The address sanitizer is not supported for libvmmalloc on FreeBSD and will be ignored.

Building NVML on Windows

Clone the NVML tree and open the solution:

	> git clone https://github.com/pmem/nvml
	> cd nvml/src
	> devenv NVML.sln

Select the desired configuration (Debug or Release) and build the solution (i.e. by pressing Ctrl-Shift-B).

Testing the Libraries

Before running the tests, you may need to prepare a test configuration file (src/test/testconfig.ps1). Please see the available configuration settings in the example file (src/test/testconfig.ps1.example).

To run the unit tests, open the PowerShell console and type:

	> cd nvml/src/test
	> RUNTESTS.ps1

To run a specific subset of tests, run for example:

	> RUNTESTS.ps1 -b debug -t short

To run just one test, run for example:

	> RUNTESTS.ps1 -b debug -i pmem_is_pmem

To modify the timeout, run:

	> RUNTESTS.ps1 -o 3m

This will set the timeout to 3 minutes.

To display all the possible options, run:

	> RUNTESTS.ps1 -h

Please refer to the src/test/README for more details on how to run different types of tests.

The librpmem and rpmemd packages

NOTE: The libfabric package required to build the librpmem and rpmemd is not yet available on stable Debian-based distributions. This makes it impossible to create Debian packages.

If you want to build Debian packages of librpmem and rpmemd run:

	$ make RPMEM_DPKG=y dpkg

Experimental Packages

Some components in the source tree are treated as experimental. By default those components are built but not installed (and thus not included in packages).

If you want to build/install experimental packages run:

	$ make EXPERIMENTAL=y [install,rpm,dpkg]

Contacts

For more information on this library, contact Krzysztof Czurylo ([email protected]), Andy Rudoff ([email protected]), or post to our Google group.