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be6a0376 DV |
1 | /* |
2 | * Copyright © 2008-2015 Intel Corporation | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice (including the next | |
12 | * paragraph) shall be included in all copies or substantial portions of the | |
13 | * Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
21 | * IN THE SOFTWARE. | |
22 | * | |
23 | */ | |
24 | ||
25 | #include <linux/oom.h> | |
26 | #include <linux/shmem_fs.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/swap.h> | |
29 | #include <linux/pci.h> | |
30 | #include <linux/dma-buf.h> | |
31 | #include <drm/drmP.h> | |
32 | #include <drm/i915_drm.h> | |
33 | ||
34 | #include "i915_drv.h" | |
35 | #include "i915_trace.h" | |
36 | ||
37 | static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task) | |
38 | { | |
39 | if (!mutex_is_locked(mutex)) | |
40 | return false; | |
41 | ||
42 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES) | |
43 | return mutex->owner == task; | |
44 | #else | |
45 | /* Since UP may be pre-empted, we cannot assume that we own the lock */ | |
46 | return false; | |
47 | #endif | |
48 | } | |
49 | ||
eb0b44ad DV |
50 | /** |
51 | * i915_gem_shrink - Shrink buffer object caches | |
52 | * @dev_priv: i915 device | |
53 | * @target: amount of memory to make available, in pages | |
54 | * @flags: control flags for selecting cache types | |
55 | * | |
56 | * This function is the main interface to the shrinker. It will try to release | |
57 | * up to @target pages of main memory backing storage from buffer objects. | |
58 | * Selection of the specific caches can be done with @flags. This is e.g. useful | |
59 | * when purgeable objects should be removed from caches preferentially. | |
60 | * | |
61 | * Note that it's not guaranteed that released amount is actually available as | |
62 | * free system memory - the pages might still be in-used to due to other reasons | |
63 | * (like cpu mmaps) or the mm core has reused them before we could grab them. | |
64 | * Therefore code that needs to explicitly shrink buffer objects caches (e.g. to | |
65 | * avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all(). | |
66 | * | |
67 | * Also note that any kind of pinning (both per-vma address space pins and | |
68 | * backing storage pins at the buffer object level) result in the shrinker code | |
69 | * having to skip the object. | |
70 | * | |
71 | * Returns: | |
72 | * The number of pages of backing storage actually released. | |
73 | */ | |
be6a0376 DV |
74 | unsigned long |
75 | i915_gem_shrink(struct drm_i915_private *dev_priv, | |
76 | long target, unsigned flags) | |
77 | { | |
78 | const struct { | |
79 | struct list_head *list; | |
80 | unsigned int bit; | |
81 | } phases[] = { | |
82 | { &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND }, | |
83 | { &dev_priv->mm.bound_list, I915_SHRINK_BOUND }, | |
84 | { NULL, 0 }, | |
85 | }, *phase; | |
86 | unsigned long count = 0; | |
87 | ||
88 | /* | |
89 | * As we may completely rewrite the (un)bound list whilst unbinding | |
90 | * (due to retiring requests) we have to strictly process only | |
91 | * one element of the list at the time, and recheck the list | |
92 | * on every iteration. | |
93 | * | |
94 | * In particular, we must hold a reference whilst removing the | |
95 | * object as we may end up waiting for and/or retiring the objects. | |
96 | * This might release the final reference (held by the active list) | |
97 | * and result in the object being freed from under us. This is | |
98 | * similar to the precautions the eviction code must take whilst | |
99 | * removing objects. | |
100 | * | |
101 | * Also note that although these lists do not hold a reference to | |
102 | * the object we can safely grab one here: The final object | |
103 | * unreferencing and the bound_list are both protected by the | |
104 | * dev->struct_mutex and so we won't ever be able to observe an | |
105 | * object on the bound_list with a reference count equals 0. | |
106 | */ | |
107 | for (phase = phases; phase->list; phase++) { | |
108 | struct list_head still_in_list; | |
109 | ||
110 | if ((flags & phase->bit) == 0) | |
111 | continue; | |
112 | ||
113 | INIT_LIST_HEAD(&still_in_list); | |
114 | while (count < target && !list_empty(phase->list)) { | |
115 | struct drm_i915_gem_object *obj; | |
116 | struct i915_vma *vma, *v; | |
117 | ||
118 | obj = list_first_entry(phase->list, | |
119 | typeof(*obj), global_list); | |
120 | list_move_tail(&obj->global_list, &still_in_list); | |
121 | ||
122 | if (flags & I915_SHRINK_PURGEABLE && | |
123 | obj->madv != I915_MADV_DONTNEED) | |
124 | continue; | |
125 | ||
126 | drm_gem_object_reference(&obj->base); | |
127 | ||
128 | /* For the unbound phase, this should be a no-op! */ | |
129 | list_for_each_entry_safe(vma, v, | |
130 | &obj->vma_list, vma_link) | |
131 | if (i915_vma_unbind(vma)) | |
132 | break; | |
133 | ||
134 | if (i915_gem_object_put_pages(obj) == 0) | |
135 | count += obj->base.size >> PAGE_SHIFT; | |
136 | ||
137 | drm_gem_object_unreference(&obj->base); | |
138 | } | |
139 | list_splice(&still_in_list, phase->list); | |
140 | } | |
141 | ||
142 | return count; | |
143 | } | |
144 | ||
eb0b44ad DV |
145 | /** |
146 | * i915_gem_shrink - Shrink buffer object caches completely | |
147 | * @dev_priv: i915 device | |
148 | * | |
149 | * This is a simple wraper around i915_gem_shrink() to aggressively shrink all | |
150 | * caches completely. It also first waits for and retires all outstanding | |
151 | * requests to also be able to release backing storage for active objects. | |
152 | * | |
153 | * This should only be used in code to intentionally quiescent the gpu or as a | |
154 | * last-ditch effort when memory seems to have run out. | |
155 | * | |
156 | * Returns: | |
157 | * The number of pages of backing storage actually released. | |
158 | */ | |
be6a0376 DV |
159 | unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv) |
160 | { | |
161 | i915_gem_evict_everything(dev_priv->dev); | |
162 | return i915_gem_shrink(dev_priv, LONG_MAX, | |
163 | I915_SHRINK_BOUND | I915_SHRINK_UNBOUND); | |
164 | } | |
165 | ||
166 | static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock) | |
167 | { | |
168 | if (!mutex_trylock(&dev->struct_mutex)) { | |
169 | if (!mutex_is_locked_by(&dev->struct_mutex, current)) | |
170 | return false; | |
171 | ||
172 | if (to_i915(dev)->mm.shrinker_no_lock_stealing) | |
173 | return false; | |
174 | ||
175 | *unlock = false; | |
176 | } else | |
177 | *unlock = true; | |
178 | ||
179 | return true; | |
180 | } | |
181 | ||
182 | static int num_vma_bound(struct drm_i915_gem_object *obj) | |
183 | { | |
184 | struct i915_vma *vma; | |
185 | int count = 0; | |
186 | ||
187 | list_for_each_entry(vma, &obj->vma_list, vma_link) | |
188 | if (drm_mm_node_allocated(&vma->node)) | |
189 | count++; | |
190 | ||
191 | return count; | |
192 | } | |
193 | ||
194 | static unsigned long | |
195 | i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) | |
196 | { | |
197 | struct drm_i915_private *dev_priv = | |
198 | container_of(shrinker, struct drm_i915_private, mm.shrinker); | |
199 | struct drm_device *dev = dev_priv->dev; | |
200 | struct drm_i915_gem_object *obj; | |
201 | unsigned long count; | |
202 | bool unlock; | |
203 | ||
204 | if (!i915_gem_shrinker_lock(dev, &unlock)) | |
205 | return 0; | |
206 | ||
207 | count = 0; | |
208 | list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) | |
209 | if (obj->pages_pin_count == 0) | |
210 | count += obj->base.size >> PAGE_SHIFT; | |
211 | ||
212 | list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) { | |
213 | if (!i915_gem_obj_is_pinned(obj) && | |
214 | obj->pages_pin_count == num_vma_bound(obj)) | |
215 | count += obj->base.size >> PAGE_SHIFT; | |
216 | } | |
217 | ||
218 | if (unlock) | |
219 | mutex_unlock(&dev->struct_mutex); | |
220 | ||
221 | return count; | |
222 | } | |
223 | ||
224 | static unsigned long | |
225 | i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) | |
226 | { | |
227 | struct drm_i915_private *dev_priv = | |
228 | container_of(shrinker, struct drm_i915_private, mm.shrinker); | |
229 | struct drm_device *dev = dev_priv->dev; | |
230 | unsigned long freed; | |
231 | bool unlock; | |
232 | ||
233 | if (!i915_gem_shrinker_lock(dev, &unlock)) | |
234 | return SHRINK_STOP; | |
235 | ||
236 | freed = i915_gem_shrink(dev_priv, | |
237 | sc->nr_to_scan, | |
238 | I915_SHRINK_BOUND | | |
239 | I915_SHRINK_UNBOUND | | |
240 | I915_SHRINK_PURGEABLE); | |
241 | if (freed < sc->nr_to_scan) | |
242 | freed += i915_gem_shrink(dev_priv, | |
243 | sc->nr_to_scan - freed, | |
244 | I915_SHRINK_BOUND | | |
245 | I915_SHRINK_UNBOUND); | |
246 | if (unlock) | |
247 | mutex_unlock(&dev->struct_mutex); | |
248 | ||
249 | return freed; | |
250 | } | |
251 | ||
252 | static int | |
253 | i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr) | |
254 | { | |
255 | struct drm_i915_private *dev_priv = | |
256 | container_of(nb, struct drm_i915_private, mm.oom_notifier); | |
257 | struct drm_device *dev = dev_priv->dev; | |
258 | struct drm_i915_gem_object *obj; | |
259 | unsigned long timeout = msecs_to_jiffies(5000) + 1; | |
260 | unsigned long pinned, bound, unbound, freed_pages; | |
261 | bool was_interruptible; | |
262 | bool unlock; | |
263 | ||
264 | while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) { | |
265 | schedule_timeout_killable(1); | |
266 | if (fatal_signal_pending(current)) | |
267 | return NOTIFY_DONE; | |
268 | } | |
269 | if (timeout == 0) { | |
270 | pr_err("Unable to purge GPU memory due lock contention.\n"); | |
271 | return NOTIFY_DONE; | |
272 | } | |
273 | ||
274 | was_interruptible = dev_priv->mm.interruptible; | |
275 | dev_priv->mm.interruptible = false; | |
276 | ||
277 | freed_pages = i915_gem_shrink_all(dev_priv); | |
278 | ||
279 | dev_priv->mm.interruptible = was_interruptible; | |
280 | ||
281 | /* Because we may be allocating inside our own driver, we cannot | |
282 | * assert that there are no objects with pinned pages that are not | |
283 | * being pointed to by hardware. | |
284 | */ | |
285 | unbound = bound = pinned = 0; | |
286 | list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) { | |
287 | if (!obj->base.filp) /* not backed by a freeable object */ | |
288 | continue; | |
289 | ||
290 | if (obj->pages_pin_count) | |
291 | pinned += obj->base.size; | |
292 | else | |
293 | unbound += obj->base.size; | |
294 | } | |
295 | list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) { | |
296 | if (!obj->base.filp) | |
297 | continue; | |
298 | ||
299 | if (obj->pages_pin_count) | |
300 | pinned += obj->base.size; | |
301 | else | |
302 | bound += obj->base.size; | |
303 | } | |
304 | ||
305 | if (unlock) | |
306 | mutex_unlock(&dev->struct_mutex); | |
307 | ||
308 | if (freed_pages || unbound || bound) | |
309 | pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n", | |
310 | freed_pages << PAGE_SHIFT, pinned); | |
311 | if (unbound || bound) | |
312 | pr_err("%lu and %lu bytes still available in the " | |
313 | "bound and unbound GPU page lists.\n", | |
314 | bound, unbound); | |
315 | ||
316 | *(unsigned long *)ptr += freed_pages; | |
317 | return NOTIFY_DONE; | |
318 | } | |
319 | ||
eb0b44ad DV |
320 | /** |
321 | * i915_gem_shrinker_init - Initialize i915 shrinker | |
322 | * @dev_priv: i915 device | |
323 | * | |
324 | * This function registers and sets up the i915 shrinker and OOM handler. | |
325 | */ | |
be6a0376 DV |
326 | void i915_gem_shrinker_init(struct drm_i915_private *dev_priv) |
327 | { | |
328 | dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan; | |
329 | dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count; | |
330 | dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS; | |
331 | register_shrinker(&dev_priv->mm.shrinker); | |
332 | ||
333 | dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom; | |
334 | register_oom_notifier(&dev_priv->mm.oom_notifier); | |
335 | } |