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author | Nicolin Chen <nicoleotsuka@gmail.com> | 2019-05-23 21:06:33 -0700 |
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committer | Christoph Hellwig <hch@lst.de> | 2019-06-03 16:00:07 +0200 |
commit | bd2e75633c8012fc8a7431c82fda66237133bf7e (patch) | |
tree | 7f7b8c21585a18f68acff279c6aa4ca8f582e6eb /LICENSES | |
parent | b1d2dc009dece4cd7e629419b52266ba51960a6b (diff) | |
download | linux-bd2e75633c8012fc8a7431c82fda66237133bf7e.tar.bz2 |
dma-contiguous: use fallback alloc_pages for single pages
The addresses within a single page are always contiguous, so it's
not so necessary to always allocate one single page from CMA area.
Since the CMA area has a limited predefined size of space, it may
run out of space in heavy use cases, where there might be quite a
lot CMA pages being allocated for single pages.
However, there is also a concern that a device might care where a
page comes from -- it might expect the page from CMA area and act
differently if the page doesn't.
This patch tries to use the fallback alloc_pages path, instead of
one-page size allocations from the global CMA area in case that a
device does not have its own CMA area. This'd save resources from
the CMA global area for more CMA allocations, and also reduce CMA
fragmentations resulted from trivial allocations.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'LICENSES')
0 files changed, 0 insertions, 0 deletions