27-06-2012, 01:16 PM
Windows Graphics Overview
Windows Graphics Overview.ppt (Size: 171.5 KB / Downloads: 45)
Longhorn Display Driver Model
Graphics Just Works
Fundamental principle
New driver model delivers:
Stability
Security
Availability (virtualization)
Performance
Staged introduction of driver model
Basic model supports current hardware (planned for Longhorn)
e.g., pre-Longhorn hardware
Advanced model utilizes new hardware features (post-Longhorn)
More efficient virtualization
Old XP driver model still supported for compatibility
No new features
Stability & Security
Application graphics state isolated from other applications
Surface data (textures, render targets, etc)
Virtual address spaces
Current rendering state
Shaders, etc
Command stream is validated
Prevents access to unauthorized resources
e.g., another application’s surfaces
Prevents illegal command streams
Avoid sending bad commands to hardware
But, still have a watchdog timer
Time out if not making forward progress
Basic driver model does sw validation in kernel
Advanced driver model does hw validation
Virtualization
Allow multiple applications to “time slice” the graphics hardware
Scheduler determines which commandstream to run
Basic driver model schedules batches
Batch = sequence of commands submitted by application
Batch can’t be interrupted once started
Advanced driver model schedules contexts
Batches accumulated in application context
Can interrupt a context and run a different one
More responsive to input changes (new work, priority changes)
Better user experience