From: Michel Dänzer michel.daenzer@amd.com
Doing so can cause things to become slow.
Print a warning at compile time and an informative message at runtime in that case.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88758 Cc: stable@vger.kernel.org Signed-off-by: Michel Dänzer michel.daenzer@amd.com --- drivers/gpu/drm/radeon/radeon_object.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 7d68223..bd3df10 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -238,6 +238,18 @@ int radeon_bo_create(struct radeon_device *rdev, * See https://bugs.freedesktop.org/show_bug.cgi?id=84627 */ bo->flags &= ~RADEON_GEM_GTT_WC; +#elif defined(CONFIG_X86) && !defined(CONFIG_X86_PAT) + /* Don't try to enable write-combining when it can't work, or things + * may be slow + * See https://bugs.freedesktop.org/show_bug.cgi?id=88758 + */ + +#warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \ + thanks to write-combining + + DRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for " + "better performance thanks to write-combining\n"); + bo->flags &= ~RADEON_GEM_GTT_WC; #endif
radeon_ttm_placement_from_domain(bo, domain);
Am 04.02.2015 um 02:19 schrieb Michel Dänzer:
From: Michel Dänzer michel.daenzer@amd.com
Doing so can cause things to become slow.
Print a warning at compile time and an informative message at runtime in that case.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88758 Cc: stable@vger.kernel.org Signed-off-by: Michel Dänzer michel.daenzer@amd.com
Interesting I wonder what the rational behind this is. I mean CONFIG_X86_PAT will obviously affect write combining, but why does it slow down things if we request something that the kernel isn't configured for?
Anyway, patch is Reviewed-by: Christian König christian.koenig@amd.com
Regards, Christian.
drivers/gpu/drm/radeon/radeon_object.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 7d68223..bd3df10 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -238,6 +238,18 @@ int radeon_bo_create(struct radeon_device *rdev, * See https://bugs.freedesktop.org/show_bug.cgi?id=84627 */ bo->flags &= ~RADEON_GEM_GTT_WC; +#elif defined(CONFIG_X86) && !defined(CONFIG_X86_PAT)
- /* Don't try to enable write-combining when it can't work, or things
* may be slow* See https://bugs.freedesktop.org/show_bug.cgi?id=88758*/+#warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \
thanks to write-combiningDRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for "
"better performance thanks to write-combining\n");bo->flags &= ~RADEON_GEM_GTT_WC; #endif
radeon_ttm_placement_from_domain(bo, domain);
On Wed, Feb 4, 2015 at 4:49 AM, Christian König deathsimple@vodafone.de wrote:
Am 04.02.2015 um 02:19 schrieb Michel Dänzer:
From: Michel Dänzer michel.daenzer@amd.com
Doing so can cause things to become slow.
Print a warning at compile time and an informative message at runtime in that case.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88758 Cc: stable@vger.kernel.org Signed-off-by: Michel Dänzer michel.daenzer@amd.com
Interesting I wonder what the rational behind this is. I mean CONFIG_X86_PAT will obviously affect write combining, but why does it slow down things if we request something that the kernel isn't configured for?
Anyway, patch is Reviewed-by: Christian König christian.koenig@amd.com
Applied to my 3.20 tree.
Thanks!
Alex
Regards, Christian.
drivers/gpu/drm/radeon/radeon_object.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 7d68223..bd3df10 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -238,6 +238,18 @@ int radeon_bo_create(struct radeon_device *rdev, * See https://bugs.freedesktop.org/show_bug.cgi?id=84627 */ bo->flags &= ~RADEON_GEM_GTT_WC; +#elif defined(CONFIG_X86) && !defined(CONFIG_X86_PAT)
/* Don't try to enable write-combining when it can't work, orthings
* may be slow* See https://bugs.freedesktop.org/show_bug.cgi?id=88758*/+#warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \
thanks to write-combiningDRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for ""better performance thanks to write-combining\n");bo->flags &= ~RADEON_GEM_GTT_WC;
dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
On 04.02.2015 18:49, Christian König wrote:
Am 04.02.2015 um 02:19 schrieb Michel Dänzer:
From: Michel Dänzer michel.daenzer@amd.com
Doing so can cause things to become slow.
Print a warning at compile time and an informative message at runtime in that case.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88758 Cc: stable@vger.kernel.org Signed-off-by: Michel Dänzer michel.daenzer@amd.com
Interesting I wonder what the rational behind this is. I mean CONFIG_X86_PAT will obviously affect write combining, but why does it slow down things if we request something that the kernel isn't configured for?
Yeah, I'm not sure exactly what happens in that case, but I don't care too much, since PAT is clearly desirable anyway.
Anyway, patch is Reviewed-by: Christian König christian.koenig@amd.com
Thanks!
dri-devel@lists.freedesktop.org
-
Alex Deucher -
Christian König -
Michel Dänzer