Hi John, On Tue, 10 Nov 2020 at 09:19, John Stultz <john.stultz@xxxxxxxxxx> wrote: > > Hey All, > So just wanted to send my last revision of my patch series > of performance optimizations to the dma-buf system heap. Thanks very much for your patches - I think the first 5 patches look good to me. I know there was a bit of discussion over adding a new system-uncached heap v/s using a flag to identify that; I think I prefer the separate heap idea, but lets ask one last time if any one else has any real objections to it. Daniel, Christian: any comments from your side on this? I am planning to merge this series to drm-misc this week if I hear no objections. > > This series reworks the system heap to use sgtables, and then > consolidates the pagelist method from the heap-helpers into the > CMA heap. After which the heap-helpers logic is removed (as it > is unused). I'd still like to find a better way to avoid some of > the logic duplication in implementing the entire dma_buf_ops > handlers per heap. But unfortunately that code is tied somewhat > to how the buffer's memory is tracked. As more heaps show up I > think we'll have a better idea how to best share code, so for > now I think this is ok. > > After this, the series introduces an optimization that > Ørjan Eide implemented for ION that avoids calling sync on > attachments that don't have a mapping. > > Next, an optimization to use larger order pages for the system > heap. This change brings us closer to the current performance > of the ION allocation code (though there still is a gap due > to ION using a mix of deferred-freeing and page pools, I'll be > looking at integrating those eventually). > > Finally, a reworked version of my uncached system heap > implementation I was submitting a few weeks back. Since it > duplicated a lot of the now reworked system heap code, I > realized it would be much simpler to add the functionality to > the system_heap implementation itself. > > While not improving the core allocation performance, the > uncached heap allocations do result in *much* improved > performance on HiKey960 as it avoids a lot of flushing and > invalidating buffers that the cpu doesn't touch often. > > Feedback on these would be great! > > thanks > -john > > New in v5: > * Added a comment explaining why the order sizes are > chosen as they are > > Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > Cc: Liam Mark <lmark@xxxxxxxxxxxxxx> > Cc: Laura Abbott <labbott@xxxxxxxxxx> > Cc: Brian Starkey <Brian.Starkey@xxxxxxx> > Cc: Hridya Valsaraju <hridya@xxxxxxxxxx> > Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx> > Cc: Sandeep Patil <sspatil@xxxxxxxxxx> > Cc: Daniel Mentz <danielmentz@xxxxxxxxxx> > Cc: Chris Goldsworthy <cgoldswo@xxxxxxxxxxxxxx> > Cc: Ørjan Eide <orjan.eide@xxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> > Cc: Simon Ser <contact@xxxxxxxxxxx> > Cc: James Jones <jajones@xxxxxxxxxx> > Cc: linux-media@xxxxxxxxxxxxxxx > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > > John Stultz (7): > dma-buf: system_heap: Rework system heap to use sgtables instead of > pagelists > dma-buf: heaps: Move heap-helper logic into the cma_heap > implementation > dma-buf: heaps: Remove heap-helpers code > dma-buf: heaps: Skip sync if not mapped > dma-buf: system_heap: Allocate higher order pages if available > dma-buf: dma-heap: Keep track of the heap device struct > dma-buf: system_heap: Add a system-uncached heap re-using the system > heap > > drivers/dma-buf/dma-heap.c | 33 +- > drivers/dma-buf/heaps/Makefile | 1 - > drivers/dma-buf/heaps/cma_heap.c | 324 +++++++++++++++--- > drivers/dma-buf/heaps/heap-helpers.c | 270 --------------- > drivers/dma-buf/heaps/heap-helpers.h | 53 --- > drivers/dma-buf/heaps/system_heap.c | 494 ++++++++++++++++++++++++--- > include/linux/dma-heap.h | 9 + > 7 files changed, 753 insertions(+), 431 deletions(-) > delete mode 100644 drivers/dma-buf/heaps/heap-helpers.c > delete mode 100644 drivers/dma-buf/heaps/heap-helpers.h > > -- > 2.17.1 > Thanks much, Best, Sumit.
