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drm/i915: Replace a calloc followed by copying data over it with malloc.

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Execbufs involve quite a bit of payload, to the extent that cache misses
show up in the profiles here, and a suspicion that some of those cachelines
may get evicted and then reloaded in the subsequent copy.

This is still abstracted like drm_calloc_large since we want to check for
size overflow, and because we want to choose between kmalloc and vmalloc
on the fly.  cairo's interface for malloc-with-calloc's-args was used as
the model.

Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Eric Anholt 2009-11-22 03:49:37 +01:00
commit c8e0f93a38
2 changed files with 18 additions and 5 deletions
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4
drivers/gpu/drm/i915/i915_gem.c
View file

@ -3563,8 +3563,8 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
return -EINVAL; return -EINVAL;
} }
/* Copy in the exec list from userland */ /* Copy in the exec list from userland */
exec_list = drm_calloc_large(sizeof(*exec_list), args->buffer_count); exec_list = drm_malloc_ab(sizeof(*exec_list), args->buffer_count);
object_list = drm_calloc_large(sizeof(*object_list), args->buffer_count); object_list = drm_malloc_ab(sizeof(*object_list), args->buffer_count);
if (exec_list == NULL || object_list == NULL) { if (exec_list == NULL || object_list == NULL) {
DRM_ERROR("Failed to allocate exec or object list " DRM_ERROR("Failed to allocate exec or object list "
"for %d buffers\n", "for %d buffers\n",

19
include/drm/drmP.h
View file

@ -1545,16 +1545,29 @@ static __inline__ void drm_core_dropmap(struct drm_local_map *map)
static __inline__ void *drm_calloc_large(size_t nmemb, size_t size) static __inline__ void *drm_calloc_large(size_t nmemb, size_t size)
{ {
if (size * nmemb <= PAGE_SIZE)
return kcalloc(nmemb, size, GFP_KERNEL);
if (size != 0 && nmemb > ULONG_MAX / size) if (size != 0 && nmemb > ULONG_MAX / size)
return NULL; return NULL;
if (size * nmemb <= PAGE_SIZE)
return kcalloc(nmemb, size, GFP_KERNEL);
return __vmalloc(size * nmemb, return __vmalloc(size * nmemb,
GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
} }
/* Modeled after cairo's malloc_ab, it's like calloc but without the zeroing. */
static __inline__ void *drm_malloc_ab(size_t nmemb, size_t size)
{
if (size != 0 && nmemb > ULONG_MAX / size)
return NULL;
if (size * nmemb <= PAGE_SIZE)
return kmalloc(nmemb * size, GFP_KERNEL);
return __vmalloc(size * nmemb,
GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
}
static __inline void drm_free_large(void *ptr) static __inline void drm_free_large(void *ptr)
{ {
if (!is_vmalloc_addr(ptr)) if (!is_vmalloc_addr(ptr))