Timeout Detection and Recovery: Difference between revisions

Revision as of 10:33, 23 March 2023

Revision as of 10:54, 23 March 2023

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'''Timeout Detection and Recovery''' or '''TDR''' is a feature of the [[Windows]] operating system (OS) introduced in [[Windows Vista]]. It detects response problems from a [[graphics card]] (GPU), and if a timeout occurs, the OS will attempt a card reset to recover a functional and responsive [[desktop environment]]. However, if the attempt was unsuccessful, it results in the [[Blue Screen of Death]] (BSOD). This mitigates the scenario where the end user superfluously reboots their device should it become unresponsive.<ref name=ms>{{Cite web|url=https://docs.microsoft.com/en-us/windows-hardware/drivers/display/timeout-detection-and-recovery|title=Timeout detection and recovery (TDR) - Windows drivers|access-date=2022-03-23}}</ref>

==Timeline==

When the GPU takes more than the allotted time to process a request, the system's GPU scheduler will pick up the anomaly. It then tries to preempt the particular task, this operation has the TDR timeout.<ref name=ms/>

Once the timeout is up and the task is not completed or preempted, the kernel determines that the GPU is frozen and proceeds to inform the respective driver about the detected timeout. It is then the driver's responsibility to properly reset and reinitialize the underlying GPU.<ref name=ms/>

The OS will then do a bunch of other recovery steps needed for the system to regain responsiveness. If the entire operation was successful, the end user might see some visual artefacts and a message will be shown on the screen describing what had happened, else a BSOD might ensue.<ref name=ms/>

==See also==