@@ -965,6 +965,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
u32 old_read = obj->base.read_domains;
u32 old_write = obj->base.write_domain;
+ obj->dirty = 1; /* be paranoid */
obj->base.write_domain = obj->base.pending_write_domain;
if (obj->base.write_domain == 0)
obj->base.pending_read_domains |= obj->base.read_domains;
@@ -973,7 +974,6 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
i915_vma_move_to_active(vma, ring);
if (obj->base.write_domain) {
- obj->dirty = 1;
obj->last_write_seqno = intel_ring_get_seqno(ring);
/* check for potential scanout */
if (i915_gem_obj_ggtt_bound(obj) &&
This is a note to let you know that I have just added a patch titled drm/i915: Always mark the object as dirty when used by the GPU to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt18. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 5297e6701d03da45f1022951d903399c4b726f38 Mon Sep 17 00:00:00 2001 From: Chris Wilson <chris@chris-wilson.co.uk> Date: Mon, 31 Aug 2015 15:10:39 +0100 Subject: drm/i915: Always mark the object as dirty when used by the GPU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 51bc140431e233284660b1d22c47dec9ecdb521e upstream. There have been many hard to track down bugs whereby userspace forgot to flag a write buffer and then cause graphics corruption or a hung GPU when that buffer was later purged under memory pressure (as the buffer appeared clean, its pages would have been evicted rather than preserved and any changes more recent than in the backing storage would be lost). In retrospect this is a rare optimisation against memory pressure, already the slow path. If we always mark the buffer as dirty when accessed by the GPU, anything not used can still be evicted cheaply (ideal behaviour for mark-and-sweep eviction) but we do not run the risk of corruption. For correct read serialisation, userspace still has to notify when the GPU writes to an object. However, there are certain situations under which userspace may wish to tell white lies to the kernel... Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Kristian Høgsberg <krh@bitplanet.net> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: "Goel, Akash" <akash.goel@intel.co> Cc: Michał Winiarski <michal.winiarski@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)