On 23/12/2020 11:48, Dmitry Kadashev wrote: > On Wed, Dec 23, 2020 at 4:38 PM Dmitry Kadashev <dkadashev@xxxxxxxxx> wrote: >> Please ignore the results from the real box above (5.9.5). The memlock limit >> interfered with this, since our app was running in the background and it had a >> few rings running (most failed to be created, but not all). I'll try to make it >> fully stuck and repeat the test with the app dead. > > I've experimented with the 5.9 live boxes that were showing signs of the problem > a bit more, and I'm not entirely sure they get stuck until reboot anymore. > > I'm pretty sure it is the case with 5.6, but probably a bug was fixed since > then - the fact that 5.8 in particular had quite a few fixes that seemed > relevant is the reason we've tried 5.9 in the first place. > > And on 5.9 we might be seeing fragmentation issues indeed. I shouldn't have been > mixing my kernel versions :) Also, I did not realize a ring of size=1024 > requires 16 contiguous pages. We will experiment and observe a bit more, and > meanwhile let's consider the case closed. If the issue surfaces again I'll > update this thread. If fragmentation is to blame, it's still a problem. Let us know if you find out anything. And thanks for keeping debugging -- Pavel Begunkov
