From ee286370d6233da01788c942c2dd7e450078eb27 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 7 Apr 2015 16:20:25 +0100
Subject: [PATCH] drm/i915: Cache last obj->pages location for
 i915_gem_object_get_page()

The biggest user of i915_gem_object_get_page() is the relocation
processing during execbuffer. Typically userspace passes in a set of
relocations in sorted order. Sadly, we alternate between relocations
increasing from the start of the buffers, and relocations decreasing
from the end. However the majority of consecutive lookups will still be
in the same page. We could cache the start of the last sg chain, however
for most callers, the entire sgl is inside a single chain and so we see
no improve from the extra layer of caching.

v2: Avoid the double increment inside unlikely()

References: https://bugs.freedesktop.org/show_bug.cgi?id=88308
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
Reading git-format-patch failed