[Intel-gfx] [PATCH 5/6] drm/i915: Split idling from forcing context switch
Joonas Lahtinen
joonas.lahtinen at linux.intel.com
Wed May 25 12:57:04 UTC 2016
On ke, 2016-05-25 at 12:48 +0100, Chris Wilson wrote:
> We only need to force a switch to the kernel context placeholder during
> eviction. All other uses of i915_gpu_idle() just want to wait until
> existing work on the GPU is idle. Rename i915_gpu_idle() to
> i915_gem_wait_for_idle() to avoid any implications about "parking" the
> context first.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 2 +-
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> drivers/gpu/drm/i915/i915_gem.c | 20 +++----------
> drivers/gpu/drm/i915/i915_gem_evict.c | 51 +++++++++++++++++++++++++++++---
> drivers/gpu/drm/i915/i915_gem_gtt.c | 2 +-
> drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +-
> 6 files changed, 55 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index ac7e5692496d..615cef736356 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4941,7 +4941,7 @@ i915_drop_caches_set(void *data, u64 val)
> return ret;
>
> if (val & DROP_ACTIVE) {
> - ret = i915_gpu_idle(dev);
> + ret = i915_gem_wait_for_idle(dev_priv);
> if (ret)
> goto unlock;
> }
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index e4c8e341655c..d2719d96a274 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3283,7 +3283,7 @@ int i915_gem_init_engines(struct drm_device *dev);
> int __must_check i915_gem_init_hw(struct drm_device *dev);
> void i915_gem_init_swizzling(struct drm_device *dev);
> void i915_gem_cleanup_engines(struct drm_device *dev);
> -int __must_check i915_gpu_idle(struct drm_device *dev);
> +int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv);
> int __must_check i915_gem_suspend(struct drm_device *dev);
> void __i915_add_request(struct drm_i915_gem_request *req,
> struct drm_i915_gem_object *batch_obj,
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 61812a53e56d..e94758850c77 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3420,29 +3420,17 @@ int __i915_vma_unbind_no_wait(struct i915_vma *vma)
> return __i915_vma_unbind(vma, false);
> }
>
> -int i915_gpu_idle(struct drm_device *dev)
> +int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv)
> {
> - struct drm_i915_private *dev_priv = dev->dev_private;
> struct intel_engine_cs *engine;
> int ret;
>
> + lockdep_assert_held(&dev_priv->dev->struct_mutex);
> +
> for_each_engine(engine, dev_priv) {
> if (engine->last_context == NULL)
> continue;
>
> - if (!i915.enable_execlists) {
> - struct drm_i915_gem_request *req;
> -
> - req = i915_gem_request_alloc(engine, NULL);
> - if (IS_ERR(req))
> - return PTR_ERR(req);
> -
> - ret = i915_switch_context(req);
> - i915_add_request_no_flush(req);
> - if (ret)
> - return ret;
> - }
> -
> ret = intel_engine_idle(engine);
> if (ret)
> return ret;
> @@ -4703,7 +4691,7 @@ i915_gem_suspend(struct drm_device *dev)
> int ret = 0;
>
> mutex_lock(&dev->struct_mutex);
> - ret = i915_gpu_idle(dev);
> + ret = i915_gem_wait_for_idle(dev_priv);
> if (ret)
> goto err;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
> index b144c3f5c650..5741b58d186c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_evict.c
> +++ b/drivers/gpu/drm/i915/i915_gem_evict.c
> @@ -33,6 +33,37 @@
> #include "intel_drv.h"
> #include "i915_trace.h"
>
> +static int switch_to_pinned_context(struct drm_i915_private *dev_priv)
Why not switch_to_kernel_context as it's effectively what this does (-
execlist behaviour)?
> +{
> + struct intel_engine_cs *engine;
> +
> + if (i915.enable_execlists)
> + return 0;
> +
> + for_each_engine(engine, dev_priv) {
> + struct drm_i915_gem_request *req;
> + int ret;
> +
> + if (engine->last_context == NULL)
> + continue;
> +
> + if (engine->last_context == dev_priv->kernel_context)
> + continue;
> +
> + req = i915_gem_request_alloc(engine, dev_priv->kernel_context);
> + if (IS_ERR(req))
> + return PTR_ERR(req);
> +
> + ret = i915_switch_context(req);
> + i915_add_request_no_flush(req);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +
> static bool
> mark_free(struct i915_vma *vma, struct list_head *unwind)
> {
> @@ -150,11 +181,17 @@ none:
>
> /* Only idle the GPU and repeat the search once */
> if (pass++ == 0) {
> - ret = i915_gpu_idle(dev);
> + struct drm_i915_private *dev_priv = to_i915(dev);
> +
> + ret = switch_to_pinned_context(dev_priv);
> if (ret)
> return ret;
>
> - i915_gem_retire_requests(to_i915(dev));
> + ret = i915_gem_wait_for_idle(dev_priv);
> + if (ret)
> + return ret;
> +
> + i915_gem_retire_requests(dev_priv);
> goto search_again;
> }
>
> @@ -261,11 +298,17 @@ int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
> trace_i915_gem_evict_vm(vm);
>
> if (do_idle) {
> - ret = i915_gpu_idle(vm->dev);
> + struct drm_i915_private *dev_priv = to_i915(vm->dev);
> +
> + ret = switch_to_pinned_context(dev_priv);
> + if (ret)
> + return ret;
> +
> + ret = i915_gem_wait_for_idle(dev_priv);
> if (ret)
> return ret;
>
> - i915_gem_retire_requests(to_i915(vm->dev));
> + i915_gem_retire_requests(dev_priv);
>
> WARN_ON(!list_empty(&vm->active_list));
> }
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 46684779d4d6..84f2ed78cf88 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -2261,7 +2261,7 @@ static bool do_idling(struct drm_i915_private *dev_priv)
>
> if (unlikely(ggtt->do_idle_maps)) {
> dev_priv->mm.interruptible = false;
> - if (i915_gpu_idle(dev_priv->dev)) {
> + if (i915_gem_wait_for_idle(dev_priv)) {
> DRM_ERROR("Couldn't idle GPU\n");
This wait_for scheme and the error message do not make sense together.
> /* Wait a bit, in hopes it avoids the hang */
> udelay(10);
> diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> index 538c30499848..886a8797566d 100644
> --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
> +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> @@ -408,7 +408,7 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
> return NOTIFY_DONE;
>
> /* Force everything onto the inactive lists */
> - ret = i915_gpu_idle(dev_priv->dev);
> + ret = i915_gem_wait_for_idle(dev_priv);
> if (ret)
> goto out;
>
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
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