Heesub Shin af82009880 ANDROID: cma: redirect page allocation to CMA ...

CMA pages are designed to be used as fallback for movable allocations
and cannot be used for non-movable allocations. If CMA pages are
utilized poorly, non-movable allocations may end up getting starved if
all regular movable pages are allocated and the only pages left are
CMA. Always using CMA pages first creates unacceptable performance
problems. As a midway alternative, use CMA pages for certain
userspace allocations. The userspace pages can be migrated or dropped
quickly which giving decent utilization.

Additionally, add a fall-backs for failed CMA allocations in rmqueue()
and __rmqueue_pcplist() (the latter addition being driven by a report
by the kernel test robot); these fallbacks were dealt with differently
in the original version of the patch as the rmqueue() call chain has
changed).

Bug: 158645321
Link: https://lore.kernel.org/lkml/cover.1604282969.git.cgoldswo@codeaurora.org/
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Heesub Shin <heesub.shin@samsung.com>
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
[cgoldswo@codeaurora.org: Place in bugfixes; remove cma_alloc zone flag]
Signed-off-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
[isaacm@codeaurora.org: Resolve merge conflicts to account for new mm
features]
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Change-Id: I3dfbc42f1d12416143550042182bf16030ca7190

2021-11-05 15:36:47 +00:00

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