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

From: Roman Gushchin
Date: Fri Oct 16 2020 - 18:53:05 EST


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(-)

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2.26.2