Re: [PATCH 0/3] drm: omapdrm: Fix excessive GEM buffers DMM/CMA usage

[Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>]

gentle ping

On 19.01.22 г. 12:23 ч., Ivaylo Dimitrov wrote:
> This patch series fixes excessive DMM or CMA usage of GEM buffers leading to
> various runtime allocation failures. The series enables daily usage of devices
> without exausting limited resources like CMA or DMM space if GPU rendering is
> needed.
> 
> The first patch doesn't bring any functional changes, it just moves some
> TILER/DMM related code to a separate function, to simplify the review of the
> next two patches.
> 
> The second patch allows off-CPU rendering to non-scanout buffers. Without that
> patch, it is basically impossible to use the driver allocated GEM buffers on
> OMAP3 for anything else but a basic CPU rendered examples as if we want GPU
> rendering, we must allocate buffers as scanout buffers, which are CMA allocated.
> CMA soon gets fragmented and we start seeing allocation failures. Such failres
> in Xorg cannot be handeled gracefully, so the system is basically unusable.
> 
> Third patch fixes similar issue on OMAP4/5, where DMM/TILER spaces get
> fragmented with time, leading to allocation failures.
> 
> Series were tested on Motolola Droid4 and Nokia N900, with OMAP DDX and
> PVR EXA from https://github.com/maemo-leste/xf86-video-omap
> 
> Ivaylo Dimitrov (3):
>    drm: omapdrm: simplify omap_gem_pin
>    drm: omapdrm: Support exporting of non-contiguous GEM BOs
>    drm: omapdrm: Do no allocate non-scanout GEMs through DMM/TILER
> 
>   drivers/gpu/drm/omapdrm/omap_gem.c        | 198 +++++++++++++++++-------------
>   drivers/gpu/drm/omapdrm/omap_gem.h        |   3 +-
>   drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c |   5 +-
>   3 files changed, 116 insertions(+), 90 deletions(-)
>