TSTILE lockups on disk dump/backups

[Don Lee <MacPPC2%c.icompute.com@localhost>]

I’ve been seeing problems with my backups, which I do with dump, and pipe the data to gzip, and to an NFS-mounted filesystem.

I’ve had trouble with this from back in March of 2013. I posted to this list in June and July of 2013 when I was running MetBSD 6.0.2, also as recently as Feb 2019 when I was running NetBSD 7.2.

I thought this bug had been licked in 8.2, because I have not seen it in the past few years while running 8.2.

Unfortunately it’s back now that I have upgraded to NetBSD 9.4.

I thought that there was a bug report, but scanning in my email, I don’t see it. I did see chatter with the subject: "Re: tstile lockups - side note” and “Re: TSTILE lockups - not dead yet”.

I’ve only been on 9.4 a month or two, and I’ve already seen the lockup at least 3 times. The dump processes get stuck on “tstile” status, and can’t be killed. I have to reboot the system. If I wait too long, the whole system piles up on the tstiles and locks up hard.

Any thought about how I should deal with this? My kernel debugging skills are weak. Is there anything I can do to produce useful debug information next time this happens?

Many thanks,

-dgl-