Sometimes the drm_mm is searched from within an atomic context (yikes!) so we must be cautious and not insert a schedule() unless the caller indicates it is safe to do so.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1509 Fixes: 7be1b9b8e9d1 ("drm/mm: Break long searches in fragmented address spaces") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Zbigniew Kempczyński zbigniew.kempczynski@intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com --- drivers/gpu/drm/drm_mm.c | 21 ++++++++++--------- .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 3 ++- drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 4 +++- drivers/gpu/drm/i915/i915_gem.c | 3 ++- drivers/gpu/drm/i915/i915_gem_gtt.c | 10 ++++++--- include/drm/drm_mm.h | 11 ++++++++++ 6 files changed, 36 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index bc6e208949e8..794d9d4c2d36 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -344,7 +344,7 @@ first_hole(struct drm_mm *mm, u64 start, u64 end, u64 size, enum drm_mm_insert_mode mode) { - switch (mode) { + switch (mode & DRM_MM_INSERT_MODE) { default: case DRM_MM_INSERT_BEST: return best_hole(mm, size); @@ -367,12 +367,17 @@ next_hole(struct drm_mm *mm, struct drm_mm_node *node, enum drm_mm_insert_mode mode) { + if (mode & DRM_MM_INSERT_ONCE) + return NULL; /* check only the first hit */ + /* Searching is slow; check if we ran out of time/patience */ - cond_resched(); - if (fatal_signal_pending(current)) - return NULL; + if (mode & DRM_MM_INSERT_INTERRUPTIBLE) { + cond_resched(); + if (fatal_signal_pending(current)) + return NULL; + }
- switch (mode) { + switch (mode & DRM_MM_INSERT_MODE) { default: case DRM_MM_INSERT_BEST: return rb_hole_size_to_node(rb_prev(&node->rb_hole_size)); @@ -476,7 +481,6 @@ int drm_mm_insert_node_in_range(struct drm_mm * const mm, { struct drm_mm_node *hole; u64 remainder_mask; - bool once;
DRM_MM_BUG_ON(range_start > range_end);
@@ -489,13 +493,10 @@ int drm_mm_insert_node_in_range(struct drm_mm * const mm, if (alignment <= 1) alignment = 0;
- once = mode & DRM_MM_INSERT_ONCE; - mode &= ~DRM_MM_INSERT_ONCE; - remainder_mask = is_power_of_2(alignment) ? alignment - 1 : 0; for (hole = first_hole(mm, range_start, range_end, size, mode); hole; - hole = once ? NULL : next_hole(mm, hole, mode)) { + hole = next_hole(mm, hole, mode)) { u64 hole_start = __drm_mm_hole_node_start(hole); u64 hole_end = hole_start + hole->hole_size; u64 adj_start, adj_end; diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 6b3013d20851..1e06f5e36bbd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1057,7 +1057,8 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj, (&ggtt->vm.mm, &cache->node, PAGE_SIZE, 0, I915_COLOR_UNEVICTABLE, 0, ggtt->mappable_end, - DRM_MM_INSERT_LOW); + DRM_MM_INSERT_LOW | + DRM_MM_INSERT_INTERRUPTIBLE); mutex_unlock(&ggtt->vm.mutex); if (err) /* no inactive aperture space, use cpu reloc */ return NULL; diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c index 5557dfa83a7b..04403f8a7d3a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c @@ -43,7 +43,9 @@ int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *i915, mutex_lock(&i915->mm.stolen_lock); ret = drm_mm_insert_node_in_range(&i915->mm.stolen, node, size, alignment, 0, - start, end, DRM_MM_INSERT_BEST); + start, end, + DRM_MM_INSERT_BEST | + DRM_MM_INSERT_INTERRUPTIBLE); mutex_unlock(&i915->mm.stolen_lock);
return ret; diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 762b50b08d73..9099c311f984 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -69,7 +69,8 @@ insert_mappable_node(struct i915_ggtt *ggtt, struct drm_mm_node *node, u32 size) err = drm_mm_insert_node_in_range(&ggtt->vm.mm, node, size, 0, I915_COLOR_UNEVICTABLE, 0, ggtt->mappable_end, - DRM_MM_INSERT_LOW); + DRM_MM_INSERT_LOW | + DRM_MM_INSERT_INTERRUPTIBLE);
mutex_unlock(&ggtt->vm.mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index cb43381b0d37..899b2af13840 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -232,7 +232,8 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
err = drm_mm_insert_node_in_range(&vm->mm, node, size, alignment, color, - start, end, mode); + start, end, + mode | DRM_MM_INSERT_INTERRUPTIBLE); if (err != -ENOSPC) return err;
@@ -240,7 +241,8 @@ int i915_gem_gtt_insert(struct i915_address_space *vm, err = drm_mm_insert_node_in_range(&vm->mm, node, size, alignment, color, start, end, - DRM_MM_INSERT_BEST); + DRM_MM_INSERT_BEST | + DRM_MM_INSERT_INTERRUPTIBLE); if (err != -ENOSPC) return err; } @@ -288,7 +290,9 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
return drm_mm_insert_node_in_range(&vm->mm, node, size, alignment, color, - start, end, DRM_MM_INSERT_EVICT); + start, end, + DRM_MM_INSERT_EVICT | + DRM_MM_INSERT_INTERRUPTIBLE); }
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h index ee8b0e80ca90..cc261e33143e 100644 --- a/include/drm/drm_mm.h +++ b/include/drm/drm_mm.h @@ -141,7 +141,18 @@ enum drm_mm_insert_mode { * Does not search all holes. */ DRM_MM_INSERT_LOWEST = DRM_MM_INSERT_LOW | DRM_MM_INSERT_ONCE, + + /** + * @DRM_MM_INSERT_INTERRUPTIBLE: + * + * Check for pending signals and allow rescheduling admist the + * search. In some heavily fragmented cases, searching for an available + * node of just the right size can take a long time, in which case it + * is better to let something else run during our fruitless search. + */ + DRM_MM_INSERT_INTERRUPTIBLE = BIT(30), }; +#define DRM_MM_INSERT_MODE GENMASK(29, 0) /* all but the special bits */
/** * struct drm_mm_node - allocated block in the DRM allocator