| /* |
| * Copyright © 2008-2015 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| * |
| */ |
| |
| #include <linux/oom.h> |
| #include <linux/shmem_fs.h> |
| #include <linux/slab.h> |
| #include <linux/swap.h> |
| #include <linux/pci.h> |
| #include <linux/dma-buf.h> |
| #include <drm/drmP.h> |
| #include <drm/i915_drm.h> |
| |
| #include "i915_drv.h" |
| #include "i915_trace.h" |
| |
| static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task) |
| { |
| if (!mutex_is_locked(mutex)) |
| return false; |
| |
| #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES) |
| return mutex->owner == task; |
| #else |
| /* Since UP may be pre-empted, we cannot assume that we own the lock */ |
| return false; |
| #endif |
| } |
| |
| /** |
| * i915_gem_shrink - Shrink buffer object caches |
| * @dev_priv: i915 device |
| * @target: amount of memory to make available, in pages |
| * @flags: control flags for selecting cache types |
| * |
| * This function is the main interface to the shrinker. It will try to release |
| * up to @target pages of main memory backing storage from buffer objects. |
| * Selection of the specific caches can be done with @flags. This is e.g. useful |
| * when purgeable objects should be removed from caches preferentially. |
| * |
| * Note that it's not guaranteed that released amount is actually available as |
| * free system memory - the pages might still be in-used to due to other reasons |
| * (like cpu mmaps) or the mm core has reused them before we could grab them. |
| * Therefore code that needs to explicitly shrink buffer objects caches (e.g. to |
| * avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all(). |
| * |
| * Also note that any kind of pinning (both per-vma address space pins and |
| * backing storage pins at the buffer object level) result in the shrinker code |
| * having to skip the object. |
| * |
| * Returns: |
| * The number of pages of backing storage actually released. |
| */ |
| unsigned long |
| i915_gem_shrink(struct drm_i915_private *dev_priv, |
| unsigned long target, unsigned flags) |
| { |
| const struct { |
| struct list_head *list; |
| unsigned int bit; |
| } phases[] = { |
| { &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND }, |
| { &dev_priv->mm.bound_list, I915_SHRINK_BOUND }, |
| { NULL, 0 }, |
| }, *phase; |
| unsigned long count = 0; |
| |
| trace_i915_gem_shrink(dev_priv, target, flags); |
| i915_gem_retire_requests(dev_priv->dev); |
| |
| /* |
| * As we may completely rewrite the (un)bound list whilst unbinding |
| * (due to retiring requests) we have to strictly process only |
| * one element of the list at the time, and recheck the list |
| * on every iteration. |
| * |
| * In particular, we must hold a reference whilst removing the |
| * object as we may end up waiting for and/or retiring the objects. |
| * This might release the final reference (held by the active list) |
| * and result in the object being freed from under us. This is |
| * similar to the precautions the eviction code must take whilst |
| * removing objects. |
| * |
| * Also note that although these lists do not hold a reference to |
| * the object we can safely grab one here: The final object |
| * unreferencing and the bound_list are both protected by the |
| * dev->struct_mutex and so we won't ever be able to observe an |
| * object on the bound_list with a reference count equals 0. |
| */ |
| for (phase = phases; phase->list; phase++) { |
| struct list_head still_in_list; |
| |
| if ((flags & phase->bit) == 0) |
| continue; |
| |
| INIT_LIST_HEAD(&still_in_list); |
| while (count < target && !list_empty(phase->list)) { |
| struct drm_i915_gem_object *obj; |
| struct i915_vma *vma, *v; |
| |
| obj = list_first_entry(phase->list, |
| typeof(*obj), global_list); |
| list_move_tail(&obj->global_list, &still_in_list); |
| |
| if (flags & I915_SHRINK_PURGEABLE && |
| obj->madv != I915_MADV_DONTNEED) |
| continue; |
| |
| drm_gem_object_reference(&obj->base); |
| |
| /* For the unbound phase, this should be a no-op! */ |
| list_for_each_entry_safe(vma, v, |
| &obj->vma_list, vma_link) |
| if (i915_vma_unbind(vma)) |
| break; |
| |
| if (i915_gem_object_put_pages(obj) == 0) |
| count += obj->base.size >> PAGE_SHIFT; |
| |
| drm_gem_object_unreference(&obj->base); |
| } |
| list_splice(&still_in_list, phase->list); |
| } |
| |
| i915_gem_retire_requests(dev_priv->dev); |
| |
| return count; |
| } |
| |
| /** |
| * i915_gem_shrink_all - Shrink buffer object caches completely |
| * @dev_priv: i915 device |
| * |
| * This is a simple wraper around i915_gem_shrink() to aggressively shrink all |
| * caches completely. It also first waits for and retires all outstanding |
| * requests to also be able to release backing storage for active objects. |
| * |
| * This should only be used in code to intentionally quiescent the gpu or as a |
| * last-ditch effort when memory seems to have run out. |
| * |
| * Returns: |
| * The number of pages of backing storage actually released. |
| */ |
| unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv) |
| { |
| return i915_gem_shrink(dev_priv, -1UL, |
| I915_SHRINK_BOUND | I915_SHRINK_UNBOUND); |
| } |
| |
| static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock) |
| { |
| if (!mutex_trylock(&dev->struct_mutex)) { |
| if (!mutex_is_locked_by(&dev->struct_mutex, current)) |
| return false; |
| |
| if (to_i915(dev)->mm.shrinker_no_lock_stealing) |
| return false; |
| |
| *unlock = false; |
| } else |
| *unlock = true; |
| |
| return true; |
| } |
| |
| static int num_vma_bound(struct drm_i915_gem_object *obj) |
| { |
| struct i915_vma *vma; |
| int count = 0; |
| |
| list_for_each_entry(vma, &obj->vma_list, vma_link) { |
| if (drm_mm_node_allocated(&vma->node)) |
| count++; |
| if (vma->pin_count) |
| count++; |
| } |
| |
| return count; |
| } |
| |
| static unsigned long |
| i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(shrinker, struct drm_i915_private, mm.shrinker); |
| struct drm_device *dev = dev_priv->dev; |
| struct drm_i915_gem_object *obj; |
| unsigned long count; |
| bool unlock; |
| |
| if (!i915_gem_shrinker_lock(dev, &unlock)) |
| return 0; |
| |
| count = 0; |
| list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) |
| if (obj->pages_pin_count == 0) |
| count += obj->base.size >> PAGE_SHIFT; |
| |
| list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) { |
| if (obj->pages_pin_count == num_vma_bound(obj)) |
| count += obj->base.size >> PAGE_SHIFT; |
| } |
| |
| if (unlock) |
| mutex_unlock(&dev->struct_mutex); |
| |
| return count; |
| } |
| |
| static unsigned long |
| i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(shrinker, struct drm_i915_private, mm.shrinker); |
| struct drm_device *dev = dev_priv->dev; |
| unsigned long freed; |
| bool unlock; |
| |
| if (!i915_gem_shrinker_lock(dev, &unlock)) |
| return SHRINK_STOP; |
| |
| freed = i915_gem_shrink(dev_priv, |
| sc->nr_to_scan, |
| I915_SHRINK_BOUND | |
| I915_SHRINK_UNBOUND | |
| I915_SHRINK_PURGEABLE); |
| if (freed < sc->nr_to_scan) |
| freed += i915_gem_shrink(dev_priv, |
| sc->nr_to_scan - freed, |
| I915_SHRINK_BOUND | |
| I915_SHRINK_UNBOUND); |
| if (unlock) |
| mutex_unlock(&dev->struct_mutex); |
| |
| return freed; |
| } |
| |
| static int |
| i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(nb, struct drm_i915_private, mm.oom_notifier); |
| struct drm_device *dev = dev_priv->dev; |
| struct drm_i915_gem_object *obj; |
| unsigned long timeout = msecs_to_jiffies(5000) + 1; |
| unsigned long pinned, bound, unbound, freed_pages; |
| bool was_interruptible; |
| bool unlock; |
| |
| while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) { |
| schedule_timeout_killable(1); |
| if (fatal_signal_pending(current)) |
| return NOTIFY_DONE; |
| } |
| if (timeout == 0) { |
| pr_err("Unable to purge GPU memory due lock contention.\n"); |
| return NOTIFY_DONE; |
| } |
| |
| was_interruptible = dev_priv->mm.interruptible; |
| dev_priv->mm.interruptible = false; |
| |
| freed_pages = i915_gem_shrink_all(dev_priv); |
| |
| dev_priv->mm.interruptible = was_interruptible; |
| |
| /* Because we may be allocating inside our own driver, we cannot |
| * assert that there are no objects with pinned pages that are not |
| * being pointed to by hardware. |
| */ |
| unbound = bound = pinned = 0; |
| list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) { |
| if (!obj->base.filp) /* not backed by a freeable object */ |
| continue; |
| |
| if (obj->pages_pin_count) |
| pinned += obj->base.size; |
| else |
| unbound += obj->base.size; |
| } |
| list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) { |
| if (!obj->base.filp) |
| continue; |
| |
| if (obj->pages_pin_count) |
| pinned += obj->base.size; |
| else |
| bound += obj->base.size; |
| } |
| |
| if (unlock) |
| mutex_unlock(&dev->struct_mutex); |
| |
| if (freed_pages || unbound || bound) |
| pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n", |
| freed_pages << PAGE_SHIFT, pinned); |
| if (unbound || bound) |
| pr_err("%lu and %lu bytes still available in the " |
| "bound and unbound GPU page lists.\n", |
| bound, unbound); |
| |
| *(unsigned long *)ptr += freed_pages; |
| return NOTIFY_DONE; |
| } |
| |
| /** |
| * i915_gem_shrinker_init - Initialize i915 shrinker |
| * @dev_priv: i915 device |
| * |
| * This function registers and sets up the i915 shrinker and OOM handler. |
| */ |
| void i915_gem_shrinker_init(struct drm_i915_private *dev_priv) |
| { |
| dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan; |
| dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count; |
| dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS; |
| register_shrinker(&dev_priv->mm.shrinker); |
| |
| dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom; |
| register_oom_notifier(&dev_priv->mm.oom_notifier); |
| } |