WARNING in amdgpu_sync_keep_later / dma_fence_is_later should be rate limited

[Deucher, Alexander]

[Public]

> -----Original Message-----
> From: Rafał Miłecki <zajec5 at gmail.com>
> Sent: Thursday, September 21, 2023 3:41 PM
> To: Deucher, Alexander <Alexander.Deucher at amd.com>; Koenig, Christian
> <Christian.Koenig at amd.com>; Pan, Xinhui <Xinhui.Pan at amd.com>; amd-
> gfx at lists.freedesktop.org; dri-devel <dri-devel at lists.freedesktop.org>; Yu,
> Lang <Lang.Yu at amd.com>
> Subject: WARNING in amdgpu_sync_keep_later / dma_fence_is_later should
> be rate limited
>
> Hi,
>
> backporting commit 187916e6ed9d ("drm/amdgpu: install stub fence into
> potential unused fence pointers") to stable kernels resulted in lots of
> WARNINGs on some devices. In my case I was getting 3 WARNINGs per
> second (~150 lines logged every second). Commit ended up being reverted for
> stable but it exposed a potential problem. My messages log size was reaching
> gigabytes and was running my /tmp/ out of space.
>
> Could someone take a look at amdgpu_sync_keep_later / dma_fence_is_later
> and make sure its logging is rate limited to avoid such situations in the future,
> please?
>
> Revert in linux-5.15.x:
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=li
> nux-5.15.y&id=fae2d591f3cb31f722c7f065acf586830eab8c2a
>
> openSUSE bug report:
> https://bugzilla.opensuse.org/show_bug.cgi?id=1215523

These patches were never intended for stable.  They were picked up by Sasha's stable autoselect tools and automatically applied to stable kernels.

Alex