From 8a2421bd0d9abb3a599969d88e1910a2a101eccc Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 16 Jun 2017 15:05:22 +0100 Subject: [PATCH] drm/i915: Wait upon userptr get-user-pages within execbuffer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This simply hides the EAGAIN caused by userptr when userspace causes resource contention. However, it is quite beneficial with highly contended userptr users as we avoid repeating the setup costs and kernel-user context switches. Signed-off-by: Chris Wilson Reviewed-by: Michał Winiarski --- drivers/gpu/drm/i915/i915_drv.c | 1 + drivers/gpu/drm/i915/i915_drv.h | 10 +++++++++- drivers/gpu/drm/i915/i915_gem.c | 4 +++- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 +++ drivers/gpu/drm/i915/i915_gem_userptr.c | 18 +++++++++++++++--- 5 files changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index a534412a5551..e33a2ed9244c 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -579,6 +579,7 @@ static void i915_gem_fini(struct drm_i915_private *dev_priv) intel_uc_fini_hw(dev_priv); i915_gem_cleanup_engines(dev_priv); i915_gem_context_fini(dev_priv); + i915_gem_cleanup_userptr(dev_priv); mutex_unlock(&dev_priv->drm.struct_mutex); i915_gem_drain_freed_objects(dev_priv); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 7e182dd7e356..e750be52b04b 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1453,6 +1453,13 @@ struct i915_gem_mm { /** LRU list of objects with fence regs on them. */ struct list_head fence_list; + /** + * Workqueue to fault in userptr pages, flushed by the execbuf + * when required but otherwise left to userspace to try again + * on EAGAIN. + */ + struct workqueue_struct *userptr_wq; + u64 unordered_timeline; /* the indicator for dispatch video commands on two BSD rings */ @@ -3228,7 +3235,8 @@ int i915_gem_set_tiling_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); int i915_gem_get_tiling_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); -void i915_gem_init_userptr(struct drm_i915_private *dev_priv); +int i915_gem_init_userptr(struct drm_i915_private *dev_priv); +void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv); int i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file); int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data, diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index fcdc452f28bb..96b344901a7b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4804,7 +4804,9 @@ int i915_gem_init(struct drm_i915_private *dev_priv) */ intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL); - i915_gem_init_userptr(dev_priv); + ret = i915_gem_init_userptr(dev_priv); + if (ret) + goto out_unlock; ret = i915_gem_init_ggtt(dev_priv); if (ret) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 3eaf07dfbe62..f4b02ef3987f 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1499,6 +1499,9 @@ repeat: goto out; } + /* A frequent cause for EAGAIN are currently unavailable client pages */ + flush_workqueue(eb->i915->mm.userptr_wq); + err = i915_mutex_lock_interruptible(dev); if (err) { mutex_lock(&dev->struct_mutex); diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c index 05c36f663550..ccd09e8419f5 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -378,7 +378,7 @@ __i915_mm_struct_free(struct kref *kref) mutex_unlock(&mm->i915->mm_lock); INIT_WORK(&mm->work, __i915_mm_struct_free__worker); - schedule_work(&mm->work); + queue_work(mm->i915->mm.userptr_wq, &mm->work); } static void @@ -598,7 +598,7 @@ __i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj) get_task_struct(work->task); INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker); - schedule_work(&work->work); + queue_work(to_i915(obj->base.dev)->mm.userptr_wq, &work->work); return ERR_PTR(-EAGAIN); } @@ -830,8 +830,20 @@ i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file return 0; } -void i915_gem_init_userptr(struct drm_i915_private *dev_priv) +int i915_gem_init_userptr(struct drm_i915_private *dev_priv) { mutex_init(&dev_priv->mm_lock); hash_init(dev_priv->mm_structs); + + dev_priv->mm.userptr_wq = + alloc_workqueue("i915-userptr-acquire", WQ_HIGHPRI, 0); + if (!dev_priv->mm.userptr_wq) + return -ENOMEM; + + return 0; +} + +void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv) +{ + destroy_workqueue(dev_priv->mm.userptr_wq); } -- 2.20.1