config DRM_I915_REQUEST_TIMEOUT int "Default timeout for requests (ms)" default 20000 # milliseconds help Configures the default timeout after which any user submissions will be forcefully terminated. Beware setting this value lower, or close to heartbeat interval rounded to whole seconds times three, in order to avoid allowing misbehaving applications causing total rendering failure in unrelated clients. May be 0 to disable the timeout. config DRM_I915_FENCE_TIMEOUT int "Timeout for unsignaled foreign fences (ms, jiffy granularity)" default 10000 # milliseconds help When listening to a foreign fence, we install a supplementary timer to ensure that we are always signaled and our userspace is able to make forward progress. This value specifies the timeout used for an unsignaled foreign fence. May be 0 to disable the timeout, and rely on the foreign fence being eventually signaled. config DRM_I915_USERFAULT_AUTOSUSPEND int "Runtime autosuspend delay for userspace GGTT mmaps (ms)" default 250 # milliseconds help On runtime suspend, as we suspend the device, we have to revoke userspace GGTT mmaps and force userspace to take a pagefault on their next access. The revocation and subsequent recreation of the GGTT mmap can be very slow and so we impose a small hysteris that complements the runtime-pm autosuspend and provides a lower floor on the autosuspend delay. May be 0 to disable the extra delay and solely use the device level runtime pm autosuspend delay tunable. config DRM_I915_HEARTBEAT_INTERVAL int "Interval between heartbeat pulses (ms)" default 2500 # milliseconds help The driver sends a periodic heartbeat down all active engines to check the health of the GPU and undertake regular house-keeping of internal driver state. This is adjustable via /sys/class/drm/card?/engine/*/heartbeat_interval_ms May be 0 to disable heartbeats and therefore disable automatic GPU hang detection. config DRM_I915_PREEMPT_TIMEOUT int "Preempt timeout (ms, jiffy granularity)" default 640 # milliseconds help How long to wait (in milliseconds) for a preemption event to occur when submitting a new context. 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. This is adjustable via /sys/class/drm/card?/engine/*/preempt_timeout_ms May be 0 to disable the timeout. The compiled in default may get overridden at driver probe time on certain platforms and certain engines which will be reflected in the sysfs control. config DRM_I915_PREEMPT_TIMEOUT_COMPUTE int "Preempt timeout for compute engines (ms, jiffy granularity)" default 7500 # milliseconds help How long to wait (in milliseconds) for a preemption event to occur when submitting a new context to a compute capable engine. 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. This is adjustable via /sys/class/drm/card?/engine/*/preempt_timeout_ms May be 0 to disable the timeout. The compiled in default may get overridden at driver probe time on certain platforms and certain engines which will be reflected in the sysfs control. config DRM_I915_MAX_REQUEST_BUSYWAIT int "Busywait for request completion limit (ns)" default 8000 # nanoseconds help Before sleeping waiting for a request (GPU operation) to complete, we may spend some time polling for its completion. As the IRQ may take a non-negligible time to setup, we do a short spin first to check if the request will complete in the time it would have taken us to enable the interrupt. This is adjustable via /sys/class/drm/card?/engine/*/max_busywait_duration_ns May be 0 to disable the initial spin. In practice, we estimate the cost of enabling the interrupt (if currently disabled) to be a few microseconds. config DRM_I915_STOP_TIMEOUT int "How long to wait for an engine to quiesce gracefully before reset (ms)" default 100 # milliseconds help By stopping submission and sleeping for a short time before resetting the GPU, we allow the innocent contexts also on the system to quiesce. It is then less likely for a hanging context to cause collateral damage as the system is reset in order to recover. The corollary is that the reset itself may take longer and so be more disruptive to interactive or low latency workloads. This is adjustable via /sys/class/drm/card?/engine/*/stop_timeout_ms config DRM_I915_TIMESLICE_DURATION int "Scheduling quantum for userspace batches (ms, jiffy granularity)" default 1 # milliseconds help When two user batches of equal priority are executing, we will alternate execution of each batch to ensure forward progress of all users. This is necessary in some cases where there may be an implicit dependency between those batches that requires concurrent execution in order for them to proceed, e.g. they interact with each other via userspace semaphores. Each context is scheduled for execution for the timeslice duration, before switching to the next context. This is adjustable via /sys/class/drm/card?/engine/*/timeslice_duration_ms May be 0 to disable timeslicing.