From 821188778b9be2050d45490c4b2b009d51f041e0 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 18 Aug 2016 17:17:05 +0100 Subject: [PATCH] drm/i915: Choose not to evict faultable objects from the GGTT Often times we do not want to evict mapped objects from the GGTT as these are quite expensive to teardown and frequently reused (causing an equally, if not more so, expensive setup). In particular, when faulting in a new object we want to avoid evicting an active object, or else we may trigger a page-fault-of-doom as we ping-pong between evicting two objects. Signed-off-by: Chris Wilson Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-26-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 12 ++++++++++-- drivers/gpu/drm/i915/i915_gem_evict.c | 7 +++++-- drivers/gpu/drm/i915/i915_gem_gtt.h | 1 + 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 9811980d6837..a13290a8ba30 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1706,6 +1706,7 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) struct i915_vma *vma; pgoff_t page_offset; unsigned long pfn; + unsigned int flags; int ret; /* We don't use vmf->pgoff since that has the fake offset */ @@ -1735,9 +1736,16 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) goto err_unlock; } + /* If the object is smaller than a couple of partial vma, it is + * not worth only creating a single partial vma - we may as well + * clear enough space for the full object. + */ + flags = PIN_MAPPABLE; + if (obj->base.size > 2 * MIN_CHUNK_PAGES << PAGE_SHIFT) + flags |= PIN_NONBLOCK | PIN_NONFAULT; + /* Now pin it into the GTT as needed */ - vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, - PIN_MAPPABLE | PIN_NONBLOCK); + vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, flags); if (IS_ERR(vma)) { struct i915_ggtt_view view; unsigned int chunk_size; diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c index f76c06e92677..815d5fbe07ac 100644 --- a/drivers/gpu/drm/i915/i915_gem_evict.c +++ b/drivers/gpu/drm/i915/i915_gem_evict.c @@ -47,7 +47,7 @@ gpu_is_idle(struct drm_i915_private *dev_priv) } static bool -mark_free(struct i915_vma *vma, struct list_head *unwind) +mark_free(struct i915_vma *vma, unsigned int flags, struct list_head *unwind) { if (i915_vma_is_pinned(vma)) return false; @@ -55,6 +55,9 @@ mark_free(struct i915_vma *vma, struct list_head *unwind) if (WARN_ON(!list_empty(&vma->exec_list))) return false; + if (flags & PIN_NONFAULT && vma->obj->fault_mappable) + return false; + list_add(&vma->exec_list, unwind); return drm_mm_scan_add_block(&vma->node); } @@ -129,7 +132,7 @@ i915_gem_evict_something(struct i915_address_space *vm, phase = phases; do { list_for_each_entry(vma, *phase, vm_link) - if (mark_free(vma, &eviction_list)) + if (mark_free(vma, flags, &eviction_list)) goto found; } while (*++phase); diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h index c88af2ab5538..9248a0e0b286 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.h +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h @@ -637,6 +637,7 @@ void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj); #define PIN_NONBLOCK BIT(0) #define PIN_MAPPABLE BIT(1) #define PIN_ZONE_4G BIT(2) +#define PIN_NONFAULT BIT(3) #define PIN_MBZ BIT(5) /* I915_VMA_PIN_OVERFLOW */ #define PIN_GLOBAL BIT(6) /* I915_VMA_GLOBAL_BIND */ -- GitLab