[Intel-gfx] [PATCH 2/2] drm/i915: mark pwrite/pread slowpaths with unlikely

[Daniel Vetter]

Beside helping the compiler untangle this maze they double-up as
documentation for which a parts aren't performance-critical but just
around to keep old (but already dead-slow) userspace from breaking.

Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 4219bd1..c5f4eb7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -318,7 +318,7 @@ shmem_pread_fast(struct page *page, int shmem_page_offset, int page_length,
 	char *vaddr;
 	int ret;
 
-	if (page_do_bit17_swizzling)
+	if (unlikely(page_do_bit17_swizzling))
 		return -EINVAL;
 
 	vaddr = kmap_atomic(page);
@@ -337,7 +337,7 @@ static void
 shmem_clflush_swizzled_range(char *addr, unsigned long length,
 			     bool swizzled)
 {
-	if (swizzled) {
+	if (unlikely(swizzled)) {
 		unsigned long start = (unsigned long) addr;
 		unsigned long end = (unsigned long) addr + length;
 
@@ -648,7 +648,7 @@ shmem_pwrite_fast(struct page *page, int shmem_page_offset, int page_length,
 	char *vaddr;
 	int ret;
 
-	if (page_do_bit17_swizzling)
+	if (unlikely(page_do_bit17_swizzling))
 		return -EINVAL;
 
 	vaddr = kmap_atomic(page);
@@ -678,7 +678,7 @@ shmem_pwrite_slow(struct page *page, int shmem_page_offset, int page_length,
 	int ret;
 
 	vaddr = kmap(page);
-	if (needs_clflush_before || page_do_bit17_swizzling)
+	if (unlikely(needs_clflush_before || page_do_bit17_swizzling))
 		shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
 					     page_length,
 					     page_do_bit17_swizzling);
-- 
1.7.8.3