23.06.2020 15:09, Mikko Perttunen пишет:
/* Command is an opcode gather from a GEM handle */ #define DRM_TEGRA_SUBMIT_COMMAND_GATHER 0 /* Command is an opcode gather from a user pointer */ #define DRM_TEGRA_SUBMIT_COMMAND_GATHER_UPTR 1
I'm a bit dubious about whether we really need to retain the non-UPTR variant. The memory-copying overhead is negligible because cmdstream's data usually is hot in CPU's cache
IIRC, the most (if not all) of the modern DRM drivers drivers use the usrptr-only for the cmdstream.
At least there is no any real-world userspace example today that could benefit from a non-UPTR variant.
I'm suggesting to leave out the non-UPTR gather variant for now, keeping it in mind as a potential future extension of the submission UAPI. Any objections?