[7.0-R] Possible ufs livelock during coredump path?

[Peter Holm]

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> Peter Holm wrote:
> | Hi,
> |
> | It seems that we have a potential livelock during coredump on 7.0-R, the
> | case was that two processes trying to coredump in the same time (e.g. if
> | I configure kern.corefile=/var/tmp/%N.core and a lot of instances
> | coredump in the same time), perhaps when paging involved with it.  Upon
> | reboot, it would not recover but wait infinitely.  The box is running
> | 7.0-R/i386, UP (Origin = "GenuineIntel"  Id = 0xf34  Stepping = 4).
> |
> | Is this an known issue?  This is my own server but I do not have my
> | hands on it because it is in China, however I can provide some help if
> | the experiment can be recovered with a power-cycle :)
> |
> |
> |> AFAIK it is an old problem. I have some test where I had to disable
> core
> |> dumps for the same reason. I seem to remember that the problem is
> related
> |> to running out of VM?
>
> For my case it does not seem to be ran out of VM (at least the system
> did not printed out any messages, the log has a lot of kernel: pid 27223
> (httpd), uid 80: exited on signal 11 (core dumped) but not the out of
> swap one.
>

Nor did I, as I remember.

> So, presumably we can reliably trigger this situation (or at least your
> ones :)?
>

It's a long time since I looked at this problem, but this would seem to be
a good excuse to look at it again.

- Peter

> Cheers,
> - --
> Xin LI <delphij at delphij.net>	http://www.delphij.net/
> FreeBSD - The Power to Serve!
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