drm/i915: mark pwrite/pread slowpaths with unlikely
Beside helping the compiler untangle this maze they double-up as
documentation for which parts of the code aren't performance-critical
but just around to keep old (but already dead-slow) userspace from
breaking.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index c964dfb..b8c6248 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -298,7 +298,7 @@
char *vaddr;
int ret;
- if (page_do_bit17_swizzling)
+ if (unlikely(page_do_bit17_swizzling))
return -EINVAL;
vaddr = kmap_atomic(page);
@@ -317,7 +317,7 @@
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;
@@ -629,7 +629,7 @@
char *vaddr;
int ret;
- if (page_do_bit17_swizzling)
+ if (unlikely(page_do_bit17_swizzling))
return -EINVAL;
vaddr = kmap_atomic(page);
@@ -660,7 +660,7 @@
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);