NAME

       pmem2_deep_flush() - highly reliable persistent memory synchronization

SYNOPSIS

              #include <libpmem2.h>

              int pmem2_deep_flush(struct pmem2_map *map, void *ptr, size_t size)

DESCRIPTION

       The  pmem2_deep_flush()  function  forces any changes in the range [ptr, ptr+len) from the
       map to be stored durably in the most reliable persistence domain  available  to  software.
       In  particular,  on  supported  platforms,  this enables the code not to rely on automatic
       cache or WPQ (write pending queue) flush on power failure (ADR/eADR).

       Since this operation is usually much more expensive than regular  persist,  it  should  be
       used  sparingly.   Typically,  the  application  should  only  ever use this function as a
       precaution against hardware failures, e.g., in code that detects  silent  data  corruption
       caused by unsafe shutdown (see more in libpmem2_unsafe_shutdown(7)).

RETURN VALUE

       The pmem2_deep_flush() function returns 0 on success or an error code on failure.

ERRORS

       The pmem2_deep_flush() can fail with the following errors:

       • PMEM2_E_DEEP_FLUSH_RANGE - the provided flush range is not a subset of the map's address
         space.

       • PMEM2_E_DAX_REGION_NOT_FOUND - the underlying device region id cannot be detected.

       • -errno set by failing msync(2), while trying to perform a deep flush on  a  regular  DAX
         volume.

SEE ALSO

       msync(2),  pmem2_get_drain_fn(3),  pmem2_get_persist_fn(3)  pmem2_map(3),  libpmem2(7) and
       <http://pmem.io>