1config DRM_I915_USERFAULT_AUTOSUSPEND 2 int "Runtime autosuspend delay for userspace GGTT mmaps (ms)" 3 default 250 # milliseconds 4 help 5 On runtime suspend, as we suspend the device, we have to revoke 6 userspace GGTT mmaps and force userspace to take a pagefault on 7 their next access. The revocation and subsequent recreation of 8 the GGTT mmap can be very slow and so we impose a small hysteris 9 that complements the runtime-pm autosuspend and provides a lower 10 floor on the autosuspend delay. 11 12 May be 0 to disable the extra delay and solely use the device level 13 runtime pm autosuspend delay tunable. 14 15config DRM_I915_HEARTBEAT_INTERVAL 16 int "Interval between heartbeat pulses (ms)" 17 default 2500 # milliseconds 18 help 19 The driver sends a periodic heartbeat down all active engines to 20 check the health of the GPU and undertake regular house-keeping of 21 internal driver state. 22 23 May be 0 to disable heartbeats and therefore disable automatic GPU 24 hang detection. 25 26config DRM_I915_PREEMPT_TIMEOUT 27 int "Preempt timeout (ms, jiffy granularity)" 28 default 640 # milliseconds 29 help 30 How long to wait (in milliseconds) for a preemption event to occur 31 when submitting a new context via execlists. If the current context 32 does not hit an arbitration point and yield to HW before the timer 33 expires, the HW will be reset to allow the more important context 34 to execute. 35 36 May be 0 to disable the timeout. 37 38config DRM_I915_SPIN_REQUEST 39 int "Busywait for request completion (us)" 40 default 5 # microseconds 41 help 42 Before sleeping waiting for a request (GPU operation) to complete, 43 we may spend some time polling for its completion. As the IRQ may 44 take a non-negligible time to setup, we do a short spin first to 45 check if the request will complete in the time it would have taken 46 us to enable the interrupt. 47 48 May be 0 to disable the initial spin. In practice, we estimate 49 the cost of enabling the interrupt (if currently disabled) to be 50 a few microseconds. 51 52config DRM_I915_STOP_TIMEOUT 53 int "How long to wait for an engine to quiesce gracefully before reset (ms)" 54 default 100 # milliseconds 55 help 56 By stopping submission and sleeping for a short time before resetting 57 the GPU, we allow the innocent contexts also on the system to quiesce. 58 It is then less likely for a hanging context to cause collateral 59 damage as the system is reset in order to recover. The corollary is 60 that the reset itself may take longer and so be more disruptive to 61 interactive or low latency workloads. 62 63config DRM_I915_TIMESLICE_DURATION 64 int "Scheduling quantum for userspace batches (ms, jiffy granularity)" 65 default 1 # milliseconds 66 help 67 When two user batches of equal priority are executing, we will 68 alternate execution of each batch to ensure forward progress of 69 all users. This is necessary in some cases where there may be 70 an implicit dependency between those batches that requires 71 concurrent execution in order for them to proceed, e.g. they 72 interact with each other via userspace semaphores. Each context 73 is scheduled for execution for the timeslice duration, before 74 switching to the next context. 75 76 May be 0 to disable timeslicing. 77