From: Chris Wilson Date: Fri, 8 Apr 2016 11:11:14 +0000 (+0100) Subject: drm/i915: Avoid allocating a vmap arena for a single page X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fb8621d3bee88badeb25dccce0fb59ad145dba9e;p=deliverable%2Flinux.git drm/i915: Avoid allocating a vmap arena for a single page If we want a contiguous mapping of a single page sized object, we can forgo using vmap() and just use a regular kmap(). Note that this is only suitable if the desired pgprot_t is compatible. v2: Use is_vmalloc_addr() Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Dave Gordon Link: http://patchwork.freedesktop.org/patch/msgid/1460113874-17366-7-git-send-email-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index eaf906875cd8..f1455faecbd2 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) list_del(&obj->global_list); if (obj->mapping) { - vunmap(obj->mapping); + if (is_vmalloc_addr(obj->mapping)) + vunmap(obj->mapping); + else + kunmap(kmap_to_page(obj->mapping)); obj->mapping = NULL; } @@ -2418,13 +2421,19 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj) i915_gem_object_pin_pages(obj); if (obj->mapping == NULL) { - struct sg_page_iter sg_iter; struct page **pages; - int n; - n = obj->base.size >> PAGE_SHIFT; - pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); + pages = NULL; + if (obj->base.size == PAGE_SIZE) + obj->mapping = kmap(sg_page(obj->pages->sgl)); + else + pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, + sizeof(*pages), + GFP_TEMPORARY); if (pages != NULL) { + struct sg_page_iter sg_iter; + int n; + n = 0; for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)