diff options
| author | Dave Airlie <airlied@redhat.com> | 2012-09-19 03:12:41 +0200 |
|---|---|---|
| committer | Dave Airlie <airlied@gmail.com> | 2012-09-19 11:59:26 +0200 |
| commit | 87229ad9de079cb12ee09a3dc16113c390b729d5 (patch) | |
| tree | 3f2a198c4c69346656611fe284c17f8a42080541 | |
| parent | Merge branch 'drm-lcdc' of git://linuxtv.org/pinchartl/fbdev into drm-next (diff) | |
| download | linux-87229ad9de079cb12ee09a3dc16113c390b729d5.tar.xz linux-87229ad9de079cb12ee09a3dc16113c390b729d5.zip | |
drm: micro optimise cache flushing
We hit this a lot with i915 and although we'd like to engineer things to hit
it a lot less, this commit at least makes it consume a few less cycles.
from something containing
movzwl 0x0(%rip),%r10d
to
add %r8,%rdx
I only noticed it while using perf to profile something else.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/drm_cache.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c index 08758e061478..3dbc7f17eb11 100644 --- a/drivers/gpu/drm/drm_cache.c +++ b/drivers/gpu/drm/drm_cache.c @@ -37,12 +37,13 @@ drm_clflush_page(struct page *page) { uint8_t *page_virtual; unsigned int i; + const int size = boot_cpu_data.x86_clflush_size; if (unlikely(page == NULL)) return; page_virtual = kmap_atomic(page); - for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size) + for (i = 0; i < PAGE_SIZE; i += size) clflush(page_virtual + i); kunmap_atomic(page_virtual); } |