On 16/02/16 05:27, sourab.gupta@xxxxxxxxx wrote:
From: Robert Bragg <robert@xxxxxxxxxxxxx> The newly added intel_context::global_id is suitable (a globally unique 20 bit ID) for giving to the hardware as a unique context identifier. Compared to using the pinned address of a logical ring context these IDs are constant for the lifetime of a context whereas a context could be repinned at different addresses during its lifetime. Having a stable ID is useful when we need to buffer information associated with a context based on this ID so the association can't be lost. For example the OA unit writes out counter reports to a circular buffer tagged with this ID and we want to be able to accurately filter reports for a specific context, ideally without the added complexity of tracking context re-pinning while the OA buffer may contain reports with older IDs.
Unfortunately, I suspect that the GuC firmware has conflated the context ID (which ought to be a purely software-defined tag) with the (hardware) GTT page address of the LRC. So this will probably break GuC submission.
But it looks like a good idea otherwise; maybe we can get the GuC firmware updated so it doesn't make this assumption ...
.Dave. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
