From: Chris Wilson chris@chris-wilson.co.uk
commit b925708f28c2b7a3a362d709bd7f77bc75c1daac upstream.
Since dropping the set-to-gtt-domain in commit a679f58d0510 ("drm/i915: Flush pages on acquisition"), we no longer mark the contents as dirty on a write fault. This has the issue of us then not marking the pages as dirty on releasing the buffer, which means the contents are not written out to the swap device (should we ever pick that buffer as a victim). Notably, this is visible in the dumb buffer interface used for cursors. Having updated the cursor contents via mmap, and swapped away, if the shrinker should evict the old cursor, upon next reuse, the cursor would be invisible.
E.g. echo 80 > /proc/sys/kernel/sysrq ; echo f > /proc/sysrq-trigger
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111541 Fixes: a679f58d0510 ("drm/i915: Flush pages on acquisition") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Matthew Auld matthew.william.auld@gmail.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: stable@vger.kernel.org # v5.2+ Reviewed-by: Matthew Auld matthew.william.auld@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20190920121821.7223-1-chris@ch... (cherry picked from commit 5028851cdfdf78dc22eacbc44a0ab0b3f599ee4a) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -317,7 +317,11 @@ vm_fault_t i915_gem_fault(struct vm_faul msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)); GEM_BUG_ON(!obj->userfault_count);
- i915_vma_set_ggtt_write(vma); + if (write) { + GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj)); + i915_vma_set_ggtt_write(vma); + obj->mm.dirty = true; + }
err_fence: i915_vma_unpin_fence(vma);