Re: [Intel-gfx] [PATCH 0/3] add guard padding around i915_vma

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

Hi, Andi,

This has been on the list before (three times I think) and at that
point it (the guard pages) was NAK'd by Daniel as yet another
complication, and a VT-d
scanout workaround was implemented and pushed using a different
approach, initially outlined by Daniel.

Patch is 2ef6efa79fecd. Those suspend/resumes should now be fast.

I then also discussed patch 1 separately with Dave Airlie and Daniel
and since both me and Dave liked it, Daniel OK'd it, but it never made
it upstream.

Just a short heads up on the history.

/Thomas


On Wed, 2022-11-09 at 18:40 +0100, Andi Shyti wrote:
> Hi,
> 
> This series adds guards around vma's but setting a pages at the
> beginning and at the end that work as padding.
> 
> The first user of the vma guard are scanout objects which don't
> need anymore to add scratch to all the unused ggtt's and speeding
> up up considerably the boot and resume by several hundreds of
> milliseconds up to over a full second in slower machines.
> 
> Andi
> 
> Chris Wilson (3):
>   drm/i915: Wrap all access to i915_vma.node.start|size
>   drm/i915: Introduce guard pages to i915_vma
>   drm/i915: Refine VT-d scanout workaround
> 
>  drivers/gpu/drm/i915/display/intel_fbdev.c    |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_domain.c    | 13 ++++
>  .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 33 ++++++-----
>  drivers/gpu/drm/i915/gem/i915_gem_mman.c      |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_shrinker.c  |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_tiling.c    |  4 +-
>  .../gpu/drm/i915/gem/selftests/huge_pages.c   |  2 +-
>  .../i915/gem/selftests/i915_gem_client_blt.c  | 23 ++++----
>  .../drm/i915/gem/selftests/i915_gem_context.c | 15 +++--
>  .../drm/i915/gem/selftests/i915_gem_mman.c    |  2 +-
>  .../drm/i915/gem/selftests/igt_gem_utils.c    |  7 ++-
>  drivers/gpu/drm/i915/gt/gen7_renderclear.c    |  2 +-
>  drivers/gpu/drm/i915/gt/intel_ggtt.c          | 39 ++++--------
>  drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c  |  3 +-
>  drivers/gpu/drm/i915/gt/intel_renderstate.c   |  2 +-
>  .../gpu/drm/i915/gt/intel_ring_submission.c   |  2 +-
>  drivers/gpu/drm/i915/gt/selftest_engine_cs.c  |  8 +--
>  drivers/gpu/drm/i915/gt/selftest_execlists.c  | 18 +++---
>  drivers/gpu/drm/i915/gt/selftest_hangcheck.c  | 15 ++---
>  drivers/gpu/drm/i915/gt/selftest_lrc.c        | 16 ++---
>  .../drm/i915/gt/selftest_ring_submission.c    |  2 +-
>  drivers/gpu/drm/i915/gt/selftest_rps.c        | 12 ++--
>  .../gpu/drm/i915/gt/selftest_workarounds.c    |  8 +--
>  drivers/gpu/drm/i915/i915_cmd_parser.c        |  4 +-
>  drivers/gpu/drm/i915/i915_debugfs.c           |  2 +-
>  drivers/gpu/drm/i915/i915_gem_gtt.h           |  3 +-
>  drivers/gpu/drm/i915/i915_perf.c              |  2 +-
>  drivers/gpu/drm/i915/i915_vma.c               | 59 +++++++++++++----
> --
>  drivers/gpu/drm/i915/i915_vma.h               | 52 +++++++++++++++-
>  drivers/gpu/drm/i915/i915_vma_resource.c      |  4 +-
>  drivers/gpu/drm/i915/i915_vma_resource.h      | 17 ++++--
>  drivers/gpu/drm/i915/i915_vma_types.h         |  3 +-
>  drivers/gpu/drm/i915/selftests/i915_request.c | 20 +++----
>  drivers/gpu/drm/i915/selftests/igt_spinner.c  |  8 +--
>  34 files changed, 246 insertions(+), 160 deletions(-)
>