From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 15 Jan 2018 21:24:46 +0000
Subject: drm/i915: Only attempt to scan the requested number of shrinker slabs
Git-commit: c5bd1fc9a6c843c85a5cea5765cdc997f832df3c
Patch-mainline: v4.16-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Since commit 4e773c3a8a69 ("drm/i915: Wire up shrinkctl->nr_scanned"),
we track the number of objects we scan and do not wish to exceed that as
it will overly penalise our own slabs under mempressure. Given that we
now know the target number of objects to scan, use that as our guide for
deciding to shrink as opposed to the number of objects we manage to
shrink (which doesn't correspond to the numbers we report to shrinkctl).

Fixes: 4e773c3a8a69 ("drm/i915: Wire up shrinkctl->nr_scanned")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180115212455.24046-2-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
(cherry picked from commit 29d384e34c55d696cf37bd4159e05f4b14d45da0)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_gem_shrinker.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -363,13 +363,13 @@ i915_gem_shrinker_scan(struct shrinker *
 				I915_SHRINK_BOUND |
 				I915_SHRINK_UNBOUND |
 				I915_SHRINK_PURGEABLE);
-	if (freed < sc->nr_to_scan)
+	if (sc->nr_scanned < sc->nr_to_scan)
 		freed += i915_gem_shrink(i915,
 					 sc->nr_to_scan - sc->nr_scanned,
 					 &sc->nr_scanned,
 					 I915_SHRINK_BOUND |
 					 I915_SHRINK_UNBOUND);
-	if (freed < sc->nr_to_scan && current_is_kswapd()) {
+	if (sc->nr_scanned < sc->nr_to_scan && current_is_kswapd()) {
 		intel_runtime_pm_get(i915);
 		freed += i915_gem_shrink(i915,
 					 sc->nr_to_scan - sc->nr_scanned,