On 2020-09-11 13:54, Chris Goldsworthy wrote:
[PATCH v2] cma_alloc(), indefinitely retry allocations for -EBUSY
failures
On mobile devices, failure to allocate from a CMA area constitutes a
functional failure. Sometimes during CMA allocations, we have observed
that pages in a CMA area allocated through alloc_pages(), that we're
trying
to migrate away to make room for a CMA allocation, are temporarily
pinned.
This temporary pinning can occur when a process that owns the pinned
page
is being forked (the example is explained further in the commit text),
or it is
exiting. This patch addresses this issue by indefinitely retrying
allocations
that fail due to a return of -EBUSY.
** This change log was re-sent due to threading issues **
Change log:
v1: We were performing retries of the allocation a fixed number of
times.
Andrew Morton disliked this, as it didn't guarantee that the allocation
would
succeed.
https://lkml.org/lkml/2020/8/5/1096
https://lkml.org/lkml/2020/8/21/1490
v2: To address this concern, we switched to retrying indefinitely, as
opposed to
doing to retrying the allocation a limited number of times.
Chris Goldsworthy (1):
mm: cma: indefinitely retry allocations in cma_alloc
mm/cma.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
test
--
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