drm/i915: Store the execution priority on the context

In order to support userspace defining different levels of importance to
different contexts, and in particular the preferred order of execution,
store a priority value on each context. By default, the kernel's
context, which is used for idling and other background tasks, is given
minimum priority (i.e. all user contexts will execute before the kernel).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161114204105.29171-9-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 00a0c6c..0e7e33b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -936,6 +936,7 @@ struct i915_gem_context {
        /* Unique identifier for this context, used by the hw for tracking */
        unsigned int hw_id;
        u32 user_handle;
+       int priority; /* greater priorities are serviced first */
 
        u32 ggtt_alignment;
 

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 6dd4757..1f94b8d 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -476,6 +476,7 @@ int i915_gem_context_init(struct drm_device *dev)
                return PTR_ERR(ctx);
        }
 
+       ctx->priority = I915_PRIORITY_MIN; /* lowest priority; idle task */
        dev_priv->kernel_context = ctx;
 
        DRM_DEBUG_DRIVER("%s context support initialized\n",

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 13574a1..b9b5253 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -867,7 +867,7 @@ void __i915_add_request(struct drm_i915_gem_request *request, bool flush_caches)
         * run at the earliest possible convenience.
         */
        if (engine->schedule)
-               engine->schedule(request, 0);
+               engine->schedule(request, request->ctx->priority);
 
        local_bh_disable();
        i915_sw_fence_commit(&request->submit);