Hello Robin, On 6/28/22 15:31, Robin Murphy wrote: >> Hello, >> >> This patchset introduces memory shrinker for the VirtIO-GPU DRM driver >> and adds memory purging and eviction support to VirtIO-GPU driver. >> >> The new dma-buf locking convention is introduced here as well. >> >> During OOM, the shrinker will release BOs that are marked as "not needed" >> by userspace using the new madvise IOCTL, it will also evict idling BOs >> to SWAP. The userspace in this case is the Mesa VirGL driver, it will >> mark >> the cached BOs as "not needed", allowing kernel driver to release memory >> of the cached shmem BOs on lowmem situations, preventing OOM kills. >> >> The Panfrost driver is switched to use generic memory shrinker. > > I think we still have some outstanding issues here - Alyssa reported > some weirdness yesterday, so I just tried provoking a low-memory > condition locally with this series applied and a few debug options > enabled, and the results as below were... interesting. The warning and crash that you got actually are the minor issues. Alyssa caught an interesting PREEMPT_DEBUG issue in the shrinker that I haven't seen before. She is also experiencing another problem in the Panfrost driver with a bad shmem pages (I think). It is unrelated to this patchset and apparently require an extra setup for the reproduction. -- Best regards, Dmitry
