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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-23 16:31:05 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-24 01:52:10 +0300 |
| commit | 3a7a92aba8fb77162e1e9963360fd81fc15c39a5 (patch) | |
| tree | ee83ca45b7572ad4883196a85a0e7c9fb6136eb8 /drivers/gpu/drm/i915/Kconfig.profile | |
| parent | a8c51ed22b0ef20205180baa8ed30e05ea6f8505 (diff) | |
| download | linux-3a7a92aba8fb77162e1e9963360fd81fc15c39a5.tar.xz | |
drm/i915/execlists: Force preemption
If the preempted context takes too long to relinquish control, e.g. it
is stuck inside a shader with arbitration disabled, evict that context
with an engine reset. This ensures that preemptions are reasonably
responsive, providing a tighter QoS for the more important context at
the cost of flagging unresponsive contexts more frequently (i.e. instead
of using an ~10s hangcheck, we now evict at ~100ms). The challenge of
lies in picking a timeout that can be reasonably serviced by HW for
typical workloads, balancing the existing clients against the needs for
responsiveness.
Note that coupled with timeslicing, this will lead to rapid GPU "hang"
detection with multiple active contexts vying for GPU time.
The forced preemption mechanism can be compiled out with
./scripts/config --set-val DRM_I915_PREEMPT_TIMEOUT 0
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191023133108.21401-2-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/Kconfig.profile')
| -rw-r--r-- | drivers/gpu/drm/i915/Kconfig.profile | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/Kconfig.profile b/drivers/gpu/drm/i915/Kconfig.profile index 3a3881d5e44b..b071b6024152 100644 --- a/drivers/gpu/drm/i915/Kconfig.profile +++ b/drivers/gpu/drm/i915/Kconfig.profile @@ -12,6 +12,18 @@ config DRM_I915_USERFAULT_AUTOSUSPEND May be 0 to disable the extra delay and solely use the device level runtime pm autosuspend delay tunable. +config DRM_I915_PREEMPT_TIMEOUT + int "Preempt timeout (ms, jiffy granularity)" + default 100 # milliseconds + help + How long to wait (in milliseconds) for a preemption event to occur + when submitting a new context via execlists. If the current context + does not hit an arbitration point and yield to HW before the timer + expires, the HW will be reset to allow the more important context + to execute. + + May be 0 to disable the timeout. + config DRM_I915_SPIN_REQUEST int "Busywait for request completion (us)" default 5 # microseconds |