oracular (3) pmem2_source_numa_node.3.gz

NAME

       pmem2_source_numa_node() - returns data source numa node

SYNOPSIS

              #include <libpmem2.h>

              struct pmem2_source;
              int pmem2_source_numa_node(const struct pmem2_source *source, int *numa_node);

DESCRIPTION

       The  pmem2_source_numa_node()  function  retrieves the numa node of the given data source.  The numa node
       can be used to, e.g., pin threads to near-memory cores.  The numa node is stored in  *numa_node.   It  is
       the same value that is shown as numa_node in ndctl list -v.

RETURN VALUE

       The  pmem2_source_numa_node()  function  returns  0  on  success.   If the function fails, the *numa_node
       variable is left unmodified and a negative error code is returned.

ERRORS

       The pmem2_source_numa_node() can fail with the following errors:

       On all systems:

       • PMEM2_E_NOSUPP - source type or operating system not supported (see #caveats for details.)

       on Linux:

       • PMEM2_E_DAX_REGION_NOT_FOUND - no ndctl_region could be determined for the source.

       • PMEM2_E_INVALID_FILE_TYPE - if the source points to a directory.

       • -errno set by failing ndctl_new, while trying to create a new context.

CAVEATS

       This call requires libndctl to retrieve the numa  information.   It  only  works  for  sources  that  are
       actually  located  on  persistent  memory, i.e., devdax or fsdax.  As anonymous sources are not backed by
       files on persistent memory, this method is not supported for them.  It also does not work  under  Windows
       or systems without libndctl.

SEE ALSO

       errno(3),  ndctl_new(3),  pmem2_source_from_handle(3),  pmem2_source_from_fd(3), libpmem2(7), libndctl(7)
       and <https://pmem.io>