drm/i915: Avoid recursing onto active vma from the shrinker

We mark the vma as active while binding it in order to protect outselves
from being shrunk under mempressure. This only works if we are strict in
not attempting to shrink active objects.

<6> [472.618968] Workqueue: events_unbound fence_work [i915]
<4> [472.618970] Call Trace:
<4> [472.618974]  ? __schedule+0x2e5/0x810
<4> [472.618978]  schedule+0x37/0xe0
<4> [472.618982]  schedule_preempt_disabled+0xf/0x20
<4> [472.618984]  __mutex_lock+0x281/0x9c0
<4> [472.618987]  ? mark_held_locks+0x49/0x70
<4> [472.618989]  ? _raw_spin_unlock_irqrestore+0x47/0x60
<4> [472.619038]  ? i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619084]  ? i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619122]  i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619165]  i915_gem_object_unbind+0x1dc/0x400 [i915]
<4> [472.619208]  i915_gem_shrink+0x328/0x660 [i915]
<4> [472.619250]  ? i915_gem_shrink_all+0x38/0x60 [i915]
<4> [472.619282]  i915_gem_shrink_all+0x38/0x60 [i915]
<4> [472.619325]  vm_alloc_page.constprop.25+0x1aa/0x240 [i915]
<4> [472.619330]  ? rcu_read_lock_sched_held+0x4d/0x80
<4> [472.619363]  ? __alloc_pd+0xb/0x30 [i915]
<4> [472.619366]  ? module_assert_mutex_or_preempt+0xf/0x30
<4> [472.619368]  ? __module_address+0x23/0xe0
<4> [472.619371]  ? is_module_address+0x26/0x40
<4> [472.619374]  ? static_obj+0x34/0x50
<4> [472.619376]  ? lockdep_init_map+0x4d/0x1e0
<4> [472.619407]  setup_page_dma+0xd/0x90 [i915]
<4> [472.619437]  alloc_pd+0x29/0x50 [i915]
<4> [472.619470]  __gen8_ppgtt_alloc+0x443/0x6b0 [i915]
<4> [472.619503]  gen8_ppgtt_alloc+0xd7/0x300 [i915]
<4> [472.619535]  ppgtt_bind_vma+0x2a/0xe0 [i915]
<4> [472.619577]  __vma_bind+0x26/0x40 [i915]
<4> [472.619611]  fence_work+0x1c/0x90 [i915]
<4> [472.619617]  process_one_work+0x26a/0x620

Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200221221818.2861432-1-chris@chris-wilson.co.uk
(cherry picked from commit 6f24e41022f28061368776ea1514db0a6e67a9b1)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
index f7e4b39..59b387a 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
@@ -256,8 +256,7 @@ unsigned long i915_gem_shrink_all(struct drm_i915_private *i915)
        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                freed = i915_gem_shrink(i915, -1UL, NULL,
                                        I915_SHRINK_BOUND |
-                                       I915_SHRINK_UNBOUND |
-                                       I915_SHRINK_ACTIVE);
+                                       I915_SHRINK_UNBOUND);
        }
 
        return freed;
@@ -336,7 +335,6 @@ i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
        freed_pages = 0;
        with_intel_runtime_pm(&i915->runtime_pm, wakeref)
                freed_pages += i915_gem_shrink(i915, -1UL, NULL,
-                                              I915_SHRINK_ACTIVE |
                                               I915_SHRINK_BOUND |
                                               I915_SHRINK_UNBOUND |
                                               I915_SHRINK_WRITEBACK);