[PATCH rfc 0/2] mm: cma: make cma_release() non-blocking

[Roman Gushchin <guro@fb.com>]

This small patchset makes cma_release() non-blocking and simplifies
the code in hugetlbfs, where previously we had to temporarily drop
hugetlb_lock around the cma_release() call.

It should help Zi Yan on his work on 1 GB THPs: splitting a gigantic
THP under a memory pressure requires a cma_release() call. If it's
a blocking function, it complicates the already complicated code.
Because there are at least two use cases like this (hugetlbfs is
another example), I believe it's just better to make cma_release()
non-blocking.

It also makes it more consistent with other memory releasing functions
in the kernel: most of them are non-blocking.


Roman Gushchin (2):
  mm: cma: make cma_release() non-blocking
  mm: hugetlb: don't drop hugetlb_lock around cma_release() call

 mm/cma.c     | 51 +++++++++++++++++++++++++++++++++++++++++++++++++--
 mm/hugetlb.c |  6 ------
 2 files changed, 49 insertions(+), 8 deletions(-)

-- 
2.26.2