Am 27.09.2019 20:07 schrieb Ilia Mirkin <[email protected]>: On Thu, Sep 26, 2019 at 5:44 PM Ben Skeggs <[email protected]> wrote: > > On Tue, 24 Sep 2019 at 22:19, Christian König > <[email protected]> wrote: > > > > Hi guys, > > > > while working through more old TTM functionality I stumbled over the > > io_reserve_lru. > > > > Basic idea is that when this flag is set the driver->io_mem_reserve() > > callback can return -EAGAIN resulting in unmapping of other BOs. > > > > But Nouveau doesn't seem to return -EAGAIN in the call path of > > io_mem_reserve anywhere. > I believe this is a bug in Nouveau. We *should* be returning -EAGAIN > if we fail to find space in BAR1 to map the BO into.
Could this lead to SIGBUS in userspace, esp related to resume and similar situations? Yes, I would say that's exactly what would happen. Christian. A user has been experiencing this in a tricky-to-reproduce scenario with a ton of vram dedicated to framebuffers and so on (3x 4K), and the nouveau ddx falls back to memcpy in certain cases. -ilia
_______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
