Home
Reading
Searching
Subscribe
Sponsors
Statistics
Posting
Contact
Spam
Lists
Links
About
Hosting
Filtering
Features Download
Marketing
Archives
FAQ
Blog
 
Gmane
From: Konrad Rzeszutek Wilk <konrad.wilk <at> oracle.com>
Subject: [RFC PATCH] TTM DMA pool v1
Newsgroups: gmane.linux.kernel
Date: Wednesday 24th August 2011 17:16:58 UTC (over 5 years ago)
Way back in January this patchset:
http://lists.freedesktop.org/archives/dri-devel/2011-January/006905.html
was merged in, but pieces of it had to be reverted b/c they did not
work properly under PowerPC, ARM, and when swapping out pages to disk.

After a bit of discussion on the mailing list
http:[email protected]
I started working on it, but
got waylaid by other things .. and finally I am able to post the RFC
patches.

There was a lot of discussion about it and I am not sure if I captured
everybody's thoughts - if I did not - that is _not_ intentional - it has
just
been quite some time..

Anyhow .. the patches explore what the "lib/dmapool.c" does - which is to
have a
DMA pool that the device has associated with. I kind of married that code
along with drivers/gpu/drm/ttm/ttm_page_alloc.c to create a TTM DMA pool
code.
The end result is DMA pool with extra features: can do write-combine,
uncached,
writeback (and tracks them and sets back to WB when freed); tracks "cached"
pages that don't really need to be returned to a pool; and hooks up to
the shrinker code so that the pools can be shrunk.

If you guys think this set of patches make sense  - my future plans were to
move a bulk of this in the lib/dmapool.c (I spoke with Matthew Wilcox about
it
and he is OK as long as I don't introduce performance regressions).

As I mentioned, in the past, the patches I introduced broke certain
scenarios
so I've been running compile/runtime tests to make sure I don't repeat my
past
mistakes.  Both nouveau and radeon - IGP, PCI-e, and with various IOMMUs -
Calgary, GART, SWIOTLB, Xen SWIOTLB, AMD-VI work correctly (still need to
test
Intel VT-d).

My PowerPC has issues with booting a virgin 3.0 kernel (something about
"ELF image not correct") so I don't have that yet covered.

The patches are also located in a git tree:

 git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
devel/ttm.dma_pool.v1.5

And the full diffstat is:

 drivers/gpu/drm/nouveau/nouveau_mem.c    |    3 +-
 drivers/gpu/drm/nouveau/nouveau_sgdma.c  |    3 +-
 drivers/gpu/drm/radeon/radeon_gart.c     |    4 +-
 drivers/gpu/drm/radeon/radeon_ttm.c      |    3 +-
 drivers/gpu/drm/ttm/Makefile             |    3 +
 drivers/gpu/drm/ttm/ttm_bo.c             |    4 +-
 drivers/gpu/drm/ttm/ttm_memory.c         |    5 +
 drivers/gpu/drm/ttm/ttm_page_alloc.c     |   63 ++-
 drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 1311
++++++++++++++++++++++++++++++
 drivers/gpu/drm/ttm/ttm_tt.c             |    5 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c      |    4 +-
 drivers/xen/swiotlb-xen.c                |    2 +-
 include/drm/ttm/ttm_bo_driver.h          |    7 +-
 include/drm/ttm/ttm_page_alloc.h         |  100 +++-
 include/linux/swiotlb.h                  |    7 +-
 lib/swiotlb.c                            |    5 +-
 16 files changed, 1499 insertions(+), 30 deletions(-)
 
CD: 2ms