On Mon, 09 Feb 2015, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > This (partially) reverts > > commit 5537252b6b6d71fb1a8ed7395a8e5babf91953fd > Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Date: Tue Mar 25 13:23:06 2014 +0000 > > drm/i915: Invalidate our pages under memory pressure > > It appears given the right workload, that pages which are swapped out > more than once are incorrectly invalidated and discarded. I had presumed > that the swapin would mark the pages dirty again and so preserve them > against the next cycle of invalidation - that appears to be false, and > leads to memory corruption (even leak of stale pages to userspace). > > v2: Do a more throughrought revert and als get rid of the hunk in > gem_free_objects which we've tried to patch up already in > > commit 340fbd8ca1c7d6006a6b6afe716c10007bbfde85 > Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Date: Thu May 22 09:16:52 2014 +0100 > > drm/i915: Only discard backing storage on releasing the last ref > > This means this patch also fully reverts this fixup. Apparently this > is just too tricky. > > Reported-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> (v2) Pushed this one to drm-intel-next-fixes, thanks for the patch, and v2 of the patch. BR, Jani. > --- > drivers/gpu/drm/i915/i915_gem.c | 49 ++--------------------------------------- > 1 file changed, 2 insertions(+), 47 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index 36f1093e3c63..39e2af9b5fef 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -1946,26 +1946,6 @@ i915_gem_object_truncate(struct drm_i915_gem_object *obj) > obj->madv = __I915_MADV_PURGED; > } > > -/* Try to discard unwanted pages */ > -static void > -i915_gem_object_invalidate(struct drm_i915_gem_object *obj) > -{ > - struct address_space *mapping; > - > - switch (obj->madv) { > - case I915_MADV_DONTNEED: > - i915_gem_object_truncate(obj); > - case __I915_MADV_PURGED: > - return; > - } > - > - if (obj->base.filp == NULL) > - return; > - > - mapping = file_inode(obj->base.filp)->i_mapping, > - invalidate_mapping_pages(mapping, 0, (loff_t)-1); > -} > - > static void > i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj) > { > @@ -2028,7 +2008,8 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) > ops->put_pages(obj); > obj->pages = NULL; > > - i915_gem_object_invalidate(obj); > + if (i915_gem_object_is_purgeable(obj)) > + i915_gem_object_truncate(obj); > > return 0; > } > @@ -4458,30 +4439,6 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev, > return obj; > } > > -static bool discard_backing_storage(struct drm_i915_gem_object *obj) > -{ > - /* If we are the last user of the backing storage (be it shmemfs > - * pages or stolen etc), we know that the pages are going to be > - * immediately released. In this case, we can then skip copying > - * back the contents from the GPU. > - */ > - > - if (obj->madv != I915_MADV_WILLNEED) > - return false; > - > - if (obj->base.filp == NULL) > - return true; > - > - /* At first glance, this looks racy, but then again so would be > - * userspace racing mmap against close. However, the first external > - * reference to the filp can only be obtained through the > - * i915_gem_mmap_ioctl() which safeguards us against the user > - * acquiring such a reference whilst we are in the middle of > - * freeing the object. > - */ > - return atomic_long_read(&obj->base.filp->f_count) == 1; > -} > - > void i915_gem_free_object(struct drm_gem_object *gem_obj) > { > struct drm_i915_gem_object *obj = to_intel_bo(gem_obj); > @@ -4524,8 +4481,6 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj) > > if (WARN_ON(obj->pages_pin_count)) > obj->pages_pin_count = 0; > - if (discard_backing_storage(obj)) > - obj->madv = I915_MADV_DONTNEED; > i915_gem_object_put_pages(obj); > i915_gem_object_free_mmap_offset(obj); > > -- > 2.1.4 > -- Jani Nikula, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html