NAME

       rpmem_persist(), rpmem_read(), - functions to copy and read remote pools

SYNOPSIS

              #include <librpmem.h>

              int rpmem_persist(RPMEMpool *rpp, size_t offset,
                  size_t length, unsigned lane);
              int rpmem_deep_persist(RPMEMpool *rpp, size_t offset,
                  size_t length, unsigned lane);
              int rpmem_read(RPMEMpool *rpp, void *buff, size_t offset,
                  size_t length, unsigned lane);

DESCRIPTION

       The rpmem_persist() function copies data of given length at given offset from the associated local memory
       pool  and  makes  sure the data is persistent on the remote node before the function returns.  The remote
       node is identified by the rpp handle which must be returned from either rpmem_open(3) or rpmem_create(3).
       The offset is relative to the pool_addr specified in the rpmem_open(3) or rpmem_create(3) call.   If  the
       remote pool was created using rpmem_create() with non-NULL create_attr argument, offset has to be greater
       or  equal  to  4096.  In that case the first 4096 bytes of the pool is used for storing the pool matadata
       and cannot be overwritten.  If the pool was created with NULL create_attr argument, the pool metadata  is
       not  stored  with the pool and offset can be any nonnegative number.  The offset and length combined must
       not exceed the pool_size passed to rpmem_open(3) or rpmem_create(3).  The  rpmem_persist()  operation  is
       performed using the given lane number.  The lane must be less than the value returned by rpmem_open(3) or
       rpmem_create(3) through the nlanes argument (so it can take a value from 0 to nlanes - 1).

       The rpmem_deep_persist() function works in the same way as rpmem_persist(3) function, but additionally it
       flushes  the  data  to  the  lowest  possible  persistency  domain  available  from software.  Please see
       pmem_deep_persist(3) for details.

       The rpmem_read() function reads length bytes of data from a remote pool at offset and copies  it  to  the
       buffer buff.  The operation is performed on the specified lane.  The lane must be less than the value re‐
       turned  by rpmem_open(3) or rpmem_create(3) through the nlanes argument (so it can take a value from 0 to
       nlanes - 1).  The rpp must point to a remote pool opened or created previously by  rpmem_open(3)  or  rp‐
       mem_create(3).

RETURN VALUE

       The  rpmem_persist() function returns 0 if the entire memory area was made persistent on the remote node.
       Otherwise it returns a non-zero value and sets errno appropriately.

       The rpmem_read() function returns 0 if the data was read entirely.  Otherwise it returns a non-zero value
       and sets errno appropriately.

SEE ALSO

       rpmem_create(3),  rpmem_open(3),  rpmem_persist(3),   sysconf(3),   limits.conf(5),   libpmemobj(7)   and
       <http://pmem.io>

PMDK - rpmem API version 1.2                       2018-05-21                                   RPMEM_PERSIST(3)