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

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 six libraries:

• libpmem -- basic pmem operations like flushing
• libpmemblk, libpmemlog, libpmemobj -- pmem transactions
• libvmem, libvmmalloc -- volatile use of pmem

These libraries 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.

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.

The source tree is organized as follows:

• doc -- man pages describing each library contained here
• src -- the source for the libraries
• src/benchmarks -- benchmarks used by development team
• src/examples -- brief example programs using these libraries
• src/test -- unit tests used by development team
• src/tools -- various tools developed for NVML
• utils -- utilities used during build & test
• CONTRIBUTING.md -- instructions for people wishing to contribute

To build this library, you may need to install some required packages on the build system. See the before_install: rules in the .travis.yml file at the top level of the repository to get an idea what packages were required to build on the travis-ci (Ubuntu-based) systems.

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 this command at the top level:

	$ make

Once the make completes (*), 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.

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

Prerequisites: rpmbuild

To build dpkg packages on Debian-based distributions:

	$ make dpkg

Prerequisites: devscripts

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

	$ make EXTRA_CFLAGS="-Wno-error"

or

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

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.

To compile this library with enabled support for the PM-aware version of Valgrind, supply the compiler with the USE_VG_PMEMCHECK flag, for example:

	$ make EXTRA_CFLAGS=-DUSE_VG_PMEMCHECK

For Valgrind memcheck support, supply USE_VG_MEMCHECK flag. USE_VALGRIND flag enables both.

To test the libraries with AddressSanitizer and UndefinedBehaviorSanitizer, run:

	$ make EXTRA_CFLAGS="-fsanitize=address,undefined" EXTRA_LDFLAGS="-fsanitize=address,undefined" clobber all test check

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