[Intel-xe] [RFC 0/3] drm/xe: Add preemption timeout config options

[Niranjana Vishwanathapura]

On Tue, Jun 13, 2023 at 09:31:00AM +0200, Thomas Hellström wrote:
>Hi, Niranjana
>
>The plan to handle non-preemptible hardware with Xe is either to use 
>faulting or to pin memory and use CGROUPS to control the
>pinning. So when that is fully flushed out, there shouldn't be a need 
>for these changes?
>

Hi Thomas,
Currently the preemption timeout is hardcoded in driver to 640ms. These
patches are for preemptible hardware and allows preemption timeout to be
configurable during compile time. These patches are being ported form i915.

Also, the purpose is actually to give compute tasks longer time to reach
a pre-emption point after a pre-emption request has been issued. This is
necessary because Gen12 does not support mid-thread pre-emption and compute
tasks can have long running threads.

Similarly DRM_XE_PREEMPT_TIMEOUT_COMPUTE_COPY sets the default timeout
for copy engine to a higher value for PVC.

Niranjana

>/Thomas
>
>On 6/10/23 02:12, Niranjana Vishwanathapura wrote:
>>Allow preemption timeouts to be specified as a config options.
>>
>>Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
>>
>>Niranjana Vishwanathapura (3):
>>   drm/xe: Add CONFIG_DRM_XE_PREEMPT_TIMEOUT
>>   drm/xe: Add DRM_XE_PREEMPT_TIMEOUT_COMPUTE
>>   drm/xe: Add DRM_XE_PREEMPT_TIMEOUT_COMPUTE_COPY
>>
>>  drivers/gpu/drm/xe/Kconfig         |  6 +++++
>>  drivers/gpu/drm/xe/Kconfig.profile | 40 ++++++++++++++++++++++++++++++
>>  drivers/gpu/drm/xe/xe_engine.c     | 30 +++++++++++++++++++++-
>>  3 files changed, 75 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/gpu/drm/xe/Kconfig.profile
>>