[v2,0/2] Optimize dma_*_from_contiguous calls

Message

Nicolin Chen May 6, 2019, 10:33 p.m. UTC

[ Per discussion at v1, we decide to add two new functions and start
  replacing callers one by one. For this series, it only touches the
  dma-direct part. And instead of merging two PATCHes, I still keep
  them separate so that we may easily revert PATCH-2 if anything bad
  happens as last time -- PATCH-1 is supposed to be a safe cleanup. ]

This series of patches try to optimize dma_*_from_contiguous calls:
PATCH-1 abstracts two new functions and applies to dma-direct.c file.
PATCH-2 saves single pages and reduce fragmentations from CMA area.

Please check their commit messages for detail changelog.

Nicolin Chen (2):
  dma-contiguous: Abstract dma_{alloc,free}_contiguous()
  dma-contiguous: Use fallback alloc_pages for single pages

 include/linux/dma-contiguous.h | 10 ++++++
 kernel/dma/contiguous.c        | 57 ++++++++++++++++++++++++++++++++++
 kernel/dma/direct.c            | 24 +++-----------
 3 files changed, 71 insertions(+), 20 deletions(-)

Comments

Christoph Hellwig May 8, 2019, 12:52 p.m. UTC | #1

Hi Nicolin,

modulo a trivial comment typo I found this looks fine to me.  I plan
to apply it with that fixed up around -rc2 time when I open the
dma mapping tree opens for the the 5.3 merge window, unless someone
finds an issue until then.

Nicolin Chen May 8, 2019, 6:08 p.m. UTC | #2

On Wed, May 08, 2019 at 02:52:54PM +0200, Christoph Hellwig wrote:
> modulo a trivial comment typo I found this looks fine to me.  I plan
> to apply it with that fixed up around -rc2 time when I open the
> dma mapping tree opens for the the 5.3 merge window, unless someone
> finds an issue until then.

Thanks for the help all the way.