2 * Copyright © 2008-2015 Intel Corporation
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:
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
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
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 <linux/vmalloc.h>
33 #include <drm/i915_drm.h>
36 #include "i915_trace.h"
38 static bool mutex_is_locked_by(struct mutex
*mutex
, struct task_struct
*task
)
40 if (!mutex_is_locked(mutex
))
43 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
44 return mutex
->owner
== task
;
46 /* Since UP may be pre-empted, we cannot assume that we own the lock */
51 static int num_vma_bound(struct drm_i915_gem_object
*obj
)
56 list_for_each_entry(vma
, &obj
->vma_list
, obj_link
) {
57 if (drm_mm_node_allocated(&vma
->node
))
66 static bool swap_available(void)
68 return get_nr_swap_pages() > 0;
71 static bool can_release_pages(struct drm_i915_gem_object
*obj
)
73 /* Only report true if by unbinding the object and putting its pages
74 * we can actually make forward progress towards freeing physical
77 * If the pages are pinned for any other reason than being bound
78 * to the GPU, simply unbinding from the GPU is not going to succeed
79 * in releasing our pin count on the pages themselves.
81 if (obj
->pages_pin_count
!= num_vma_bound(obj
))
84 /* We can only return physical pages to the system if we can either
85 * discard the contents (because the user has marked them as being
86 * purgeable) or if we can move their contents out to swap.
88 return swap_available() || obj
->madv
== I915_MADV_DONTNEED
;
92 * i915_gem_shrink - Shrink buffer object caches
93 * @dev_priv: i915 device
94 * @target: amount of memory to make available, in pages
95 * @flags: control flags for selecting cache types
97 * This function is the main interface to the shrinker. It will try to release
98 * up to @target pages of main memory backing storage from buffer objects.
99 * Selection of the specific caches can be done with @flags. This is e.g. useful
100 * when purgeable objects should be removed from caches preferentially.
102 * Note that it's not guaranteed that released amount is actually available as
103 * free system memory - the pages might still be in-used to due to other reasons
104 * (like cpu mmaps) or the mm core has reused them before we could grab them.
105 * Therefore code that needs to explicitly shrink buffer objects caches (e.g. to
106 * avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all().
108 * Also note that any kind of pinning (both per-vma address space pins and
109 * backing storage pins at the buffer object level) result in the shrinker code
110 * having to skip the object.
113 * The number of pages of backing storage actually released.
116 i915_gem_shrink(struct drm_i915_private
*dev_priv
,
117 unsigned long target
, unsigned flags
)
120 struct list_head
*list
;
123 { &dev_priv
->mm
.unbound_list
, I915_SHRINK_UNBOUND
},
124 { &dev_priv
->mm
.bound_list
, I915_SHRINK_BOUND
},
127 unsigned long count
= 0;
129 trace_i915_gem_shrink(dev_priv
, target
, flags
);
130 i915_gem_retire_requests(dev_priv
->dev
);
133 * As we may completely rewrite the (un)bound list whilst unbinding
134 * (due to retiring requests) we have to strictly process only
135 * one element of the list at the time, and recheck the list
136 * on every iteration.
138 * In particular, we must hold a reference whilst removing the
139 * object as we may end up waiting for and/or retiring the objects.
140 * This might release the final reference (held by the active list)
141 * and result in the object being freed from under us. This is
142 * similar to the precautions the eviction code must take whilst
145 * Also note that although these lists do not hold a reference to
146 * the object we can safely grab one here: The final object
147 * unreferencing and the bound_list are both protected by the
148 * dev->struct_mutex and so we won't ever be able to observe an
149 * object on the bound_list with a reference count equals 0.
151 for (phase
= phases
; phase
->list
; phase
++) {
152 struct list_head still_in_list
;
154 if ((flags
& phase
->bit
) == 0)
157 INIT_LIST_HEAD(&still_in_list
);
158 while (count
< target
&& !list_empty(phase
->list
)) {
159 struct drm_i915_gem_object
*obj
;
160 struct i915_vma
*vma
, *v
;
162 obj
= list_first_entry(phase
->list
,
163 typeof(*obj
), global_list
);
164 list_move_tail(&obj
->global_list
, &still_in_list
);
166 if (flags
& I915_SHRINK_PURGEABLE
&&
167 obj
->madv
!= I915_MADV_DONTNEED
)
170 if (flags
& I915_SHRINK_VMAPS
&&
171 !is_vmalloc_addr(obj
->mapping
))
174 if ((flags
& I915_SHRINK_ACTIVE
) == 0 && obj
->active
)
177 if (!can_release_pages(obj
))
180 drm_gem_object_reference(&obj
->base
);
182 /* For the unbound phase, this should be a no-op! */
183 list_for_each_entry_safe(vma
, v
,
184 &obj
->vma_list
, obj_link
)
185 if (i915_vma_unbind(vma
))
188 if (i915_gem_object_put_pages(obj
) == 0)
189 count
+= obj
->base
.size
>> PAGE_SHIFT
;
191 drm_gem_object_unreference(&obj
->base
);
193 list_splice(&still_in_list
, phase
->list
);
196 i915_gem_retire_requests(dev_priv
->dev
);
202 * i915_gem_shrink_all - Shrink buffer object caches completely
203 * @dev_priv: i915 device
205 * This is a simple wraper around i915_gem_shrink() to aggressively shrink all
206 * caches completely. It also first waits for and retires all outstanding
207 * requests to also be able to release backing storage for active objects.
209 * This should only be used in code to intentionally quiescent the gpu or as a
210 * last-ditch effort when memory seems to have run out.
213 * The number of pages of backing storage actually released.
215 unsigned long i915_gem_shrink_all(struct drm_i915_private
*dev_priv
)
217 return i915_gem_shrink(dev_priv
, -1UL,
219 I915_SHRINK_UNBOUND
|
223 static bool i915_gem_shrinker_lock(struct drm_device
*dev
, bool *unlock
)
225 if (!mutex_trylock(&dev
->struct_mutex
)) {
226 if (!mutex_is_locked_by(&dev
->struct_mutex
, current
))
229 if (to_i915(dev
)->mm
.shrinker_no_lock_stealing
)
240 i915_gem_shrinker_count(struct shrinker
*shrinker
, struct shrink_control
*sc
)
242 struct drm_i915_private
*dev_priv
=
243 container_of(shrinker
, struct drm_i915_private
, mm
.shrinker
);
244 struct drm_device
*dev
= dev_priv
->dev
;
245 struct drm_i915_gem_object
*obj
;
249 if (!i915_gem_shrinker_lock(dev
, &unlock
))
253 list_for_each_entry(obj
, &dev_priv
->mm
.unbound_list
, global_list
)
254 if (can_release_pages(obj
))
255 count
+= obj
->base
.size
>> PAGE_SHIFT
;
257 list_for_each_entry(obj
, &dev_priv
->mm
.bound_list
, global_list
) {
258 if (!obj
->active
&& can_release_pages(obj
))
259 count
+= obj
->base
.size
>> PAGE_SHIFT
;
263 mutex_unlock(&dev
->struct_mutex
);
269 i915_gem_shrinker_scan(struct shrinker
*shrinker
, struct shrink_control
*sc
)
271 struct drm_i915_private
*dev_priv
=
272 container_of(shrinker
, struct drm_i915_private
, mm
.shrinker
);
273 struct drm_device
*dev
= dev_priv
->dev
;
277 if (!i915_gem_shrinker_lock(dev
, &unlock
))
280 freed
= i915_gem_shrink(dev_priv
,
283 I915_SHRINK_UNBOUND
|
284 I915_SHRINK_PURGEABLE
);
285 if (freed
< sc
->nr_to_scan
)
286 freed
+= i915_gem_shrink(dev_priv
,
287 sc
->nr_to_scan
- freed
,
289 I915_SHRINK_UNBOUND
);
291 mutex_unlock(&dev
->struct_mutex
);
296 struct shrinker_lock_uninterruptible
{
297 bool was_interruptible
;
302 i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private
*dev_priv
,
303 struct shrinker_lock_uninterruptible
*slu
,
306 unsigned long timeout
= msecs_to_jiffies(timeout_ms
) + 1;
308 while (!i915_gem_shrinker_lock(dev_priv
->dev
, &slu
->unlock
)) {
309 schedule_timeout_killable(1);
310 if (fatal_signal_pending(current
))
312 if (--timeout
== 0) {
313 pr_err("Unable to lock GPU to purge memory.\n");
318 slu
->was_interruptible
= dev_priv
->mm
.interruptible
;
319 dev_priv
->mm
.interruptible
= false;
324 i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private
*dev_priv
,
325 struct shrinker_lock_uninterruptible
*slu
)
327 dev_priv
->mm
.interruptible
= slu
->was_interruptible
;
329 mutex_unlock(&dev_priv
->dev
->struct_mutex
);
333 i915_gem_shrinker_oom(struct notifier_block
*nb
, unsigned long event
, void *ptr
)
335 struct drm_i915_private
*dev_priv
=
336 container_of(nb
, struct drm_i915_private
, mm
.oom_notifier
);
337 struct shrinker_lock_uninterruptible slu
;
338 struct drm_i915_gem_object
*obj
;
339 unsigned long pinned
, bound
, unbound
, freed_pages
;
341 if (!i915_gem_shrinker_lock_uninterruptible(dev_priv
, &slu
, 5000))
344 freed_pages
= i915_gem_shrink_all(dev_priv
);
346 /* Because we may be allocating inside our own driver, we cannot
347 * assert that there are no objects with pinned pages that are not
348 * being pointed to by hardware.
350 unbound
= bound
= pinned
= 0;
351 list_for_each_entry(obj
, &dev_priv
->mm
.unbound_list
, global_list
) {
352 if (!obj
->base
.filp
) /* not backed by a freeable object */
355 if (obj
->pages_pin_count
)
356 pinned
+= obj
->base
.size
;
358 unbound
+= obj
->base
.size
;
360 list_for_each_entry(obj
, &dev_priv
->mm
.bound_list
, global_list
) {
364 if (obj
->pages_pin_count
)
365 pinned
+= obj
->base
.size
;
367 bound
+= obj
->base
.size
;
370 i915_gem_shrinker_unlock_uninterruptible(dev_priv
, &slu
);
372 if (freed_pages
|| unbound
|| bound
)
373 pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
374 freed_pages
<< PAGE_SHIFT
, pinned
);
375 if (unbound
|| bound
)
376 pr_err("%lu and %lu bytes still available in the "
377 "bound and unbound GPU page lists.\n",
380 *(unsigned long *)ptr
+= freed_pages
;
385 i915_gem_shrinker_vmap(struct notifier_block
*nb
, unsigned long event
, void *ptr
)
387 struct drm_i915_private
*dev_priv
=
388 container_of(nb
, struct drm_i915_private
, mm
.vmap_notifier
);
389 struct shrinker_lock_uninterruptible slu
;
390 unsigned long freed_pages
;
392 if (!i915_gem_shrinker_lock_uninterruptible(dev_priv
, &slu
, 5000))
395 freed_pages
= i915_gem_shrink(dev_priv
, -1UL,
397 I915_SHRINK_UNBOUND
|
401 i915_gem_shrinker_unlock_uninterruptible(dev_priv
, &slu
);
403 *(unsigned long *)ptr
+= freed_pages
;
408 * i915_gem_shrinker_init - Initialize i915 shrinker
409 * @dev_priv: i915 device
411 * This function registers and sets up the i915 shrinker and OOM handler.
413 void i915_gem_shrinker_init(struct drm_i915_private
*dev_priv
)
415 dev_priv
->mm
.shrinker
.scan_objects
= i915_gem_shrinker_scan
;
416 dev_priv
->mm
.shrinker
.count_objects
= i915_gem_shrinker_count
;
417 dev_priv
->mm
.shrinker
.seeks
= DEFAULT_SEEKS
;
418 WARN_ON(register_shrinker(&dev_priv
->mm
.shrinker
));
420 dev_priv
->mm
.oom_notifier
.notifier_call
= i915_gem_shrinker_oom
;
421 WARN_ON(register_oom_notifier(&dev_priv
->mm
.oom_notifier
));
423 dev_priv
->mm
.vmap_notifier
.notifier_call
= i915_gem_shrinker_vmap
;
424 WARN_ON(register_vmap_purge_notifier(&dev_priv
->mm
.vmap_notifier
));
428 * i915_gem_shrinker_cleanup - Clean up i915 shrinker
429 * @dev_priv: i915 device
431 * This function unregisters the i915 shrinker and OOM handler.
433 void i915_gem_shrinker_cleanup(struct drm_i915_private
*dev_priv
)
435 WARN_ON(unregister_vmap_purge_notifier(&dev_priv
->mm
.vmap_notifier
));
436 WARN_ON(unregister_oom_notifier(&dev_priv
->mm
.oom_notifier
));
437 unregister_shrinker(&dev_priv
->mm
.shrinker
);