If we need to make room for some mappable object, then we should only victimize objects that have one or pages that occupy the visible portion of LMEM. Let's also create a new priority hint for objects that are placed in mappable memory, where we know that CPU access was requested, that way we hopefully victimize these last.
v2(Thomas): s/TTM_PL_PRIV/I915_PL_LMEM0/
Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Reviewed-by: Thomas Hellström thomas.hellstrom@linux.intel.com --- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 65 ++++++++++++++++++++++++- 1 file changed, 63 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index 36e77fcf2ef9..3790e569d6a9 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -5,8 +5,10 @@
#include <drm/ttm/ttm_bo_driver.h> #include <drm/ttm/ttm_placement.h> +#include <drm/drm_buddy.h>
#include "i915_drv.h" +#include "i915_ttm_buddy_manager.h" #include "intel_memory_region.h" #include "intel_region_ttm.h"
@@ -20,6 +22,7 @@ #define I915_TTM_PRIO_PURGE 0 #define I915_TTM_PRIO_NO_PAGES 1 #define I915_TTM_PRIO_HAS_PAGES 2 +#define I915_TTM_PRIO_NEEDS_CPU_ACCESS 3
/* * Size of struct ttm_place vector in on-stack struct ttm_placement allocs @@ -337,6 +340,7 @@ static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, const struct ttm_place *place) { struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); + struct ttm_resource *res = bo->resource;
if (!obj) return false; @@ -350,7 +354,48 @@ static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, return false;
/* Will do for now. Our pinned objects are still on TTM's LRU lists */ - return i915_gem_object_evictable(obj); + if (!i915_gem_object_evictable(obj)) + return false; + + switch (res->mem_type) { + case I915_PL_LMEM0: { + struct ttm_resource_manager *man = + ttm_manager_type(bo->bdev, res->mem_type); + struct i915_ttm_buddy_resource *bman_res = + to_ttm_buddy_resource(res); + struct drm_buddy *mm = bman_res->mm; + struct drm_buddy_block *block; + + if (!place->fpfn && !place->lpfn) + return true; + + GEM_BUG_ON(!place->lpfn); + + /* + * If we just want something mappable then we can quickly check + * if the current victim resource is using any of the CPU + * visible portion. + */ + if (!place->fpfn && + place->lpfn == i915_ttm_buddy_man_visible_size(man)) + return bman_res->used_visible_size > 0; + + /* Real range allocation */ + list_for_each_entry(block, &bman_res->blocks, link) { + unsigned long fpfn = + drm_buddy_block_offset(block) >> PAGE_SHIFT; + unsigned long lpfn = fpfn + + (drm_buddy_block_size(mm, block) >> PAGE_SHIFT); + + if (place->fpfn < lpfn && place->lpfn > fpfn) + return true; + } + return false; + } default: + break; + } + + return true; }
static void i915_ttm_evict_flags(struct ttm_buffer_object *bo, @@ -850,7 +895,23 @@ void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) } else if (!i915_gem_object_has_pages(obj)) { bo->priority = I915_TTM_PRIO_NO_PAGES; } else { - bo->priority = I915_TTM_PRIO_HAS_PAGES; + struct ttm_resource_manager *man = + ttm_manager_type(bo->bdev, bo->resource->mem_type); + + /* + * If we need to place an LMEM resource which doesn't need CPU + * access then we should try not to victimize mappable objects + * first, since we likely end up stealing more of the mappable + * portion. And likewise when we try to find space for a mappble + * object, we know not to ever victimize objects that don't + * occupy any mappable pages. + */ + if (i915_ttm_cpu_maps_iomem(bo->resource) && + i915_ttm_buddy_man_visible_size(man) < man->size && + !(obj->flags & I915_BO_ALLOC_GPU_ONLY)) + bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS; + else + bo->priority = I915_TTM_PRIO_HAS_PAGES; }
ttm_bo_move_to_lru_tail(bo, bo->resource, NULL);