comment: <> (SPDX-License-Identifier: BSD-3-Clause comment: <> (Copyright 2020, Intel Corporation)

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
SEE ALSO

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)).

Applications should generally not assume the support for this functionality in the platform, and not treat PMEM2_E_NOSUPP as a fatal error.

RETURN VALUE

The pmem2_deep_flush() returns 0 on success or one of the following error values on failure:

• 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