From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Date: Mon, 27 Nov 2017 11:12:33 +0200
Subject: drm/i915: Disable THP until we have a GPU read BW W/A
Git-commit: fd50fbb6bfdea5daa4ae4dd7b7082485ac44bdf5
Patch-mainline: v4.15-rc2
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
We seem to be missing some W/A for 2M pages and are getting
a hit on raw GPU read bandwidths (even 30%) even though the
GPU write bandwidths improve (even 10%).
For now, disable THP, which is our only practical source of
2M pages until we have a W/A for the issue.
v2:
- Be explicit that we talk about GPU bandwidths (Eero)
- s/deny/never/ because that's why (Chris)
Reported-by: Valtteri Rantala <valtteri.rantala@intel.com>
Fixes: b901bb89324a ("drm/i915/gemfs: enable THP")
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Valtteri Rantala <valtteri.rantala@intel.com>
Cc: Eero Tamminen <eero.t.tamminen@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Tested-by: Valtteri Rantala <valtteri.rantala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171127091233.7001-1-joonas.lahtinen@linux.intel.com
(cherry picked from commit 9987da4b5dcfc8b94b702d4bb94b30955eb73c75)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_gemfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/i915_gemfs.c
+++ b/drivers/gpu/drm/i915/i915_gemfs.c
@@ -52,7 +52,8 @@ int i915_gemfs_init(struct drm_i915_priv
if (has_transparent_hugepage()) {
struct super_block *sb = gemfs->mnt_sb;
- char options[] = "huge=within_size";
+ /* FIXME: Disabled until we get W/A for read BW issue. */
+ char options[] = "huge=never";
int flags = 0;
int err;