Re: VM corruption on standby

> On 20 Aug 2025, at 00:55, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Andrey Borodin <x4mmm(at)yandex-team(dot)ru> writes:
>> I believe there is a bug with PageIsAllVisible(page) && visibilitymap_clear(). But I cannot prove it with an injection point test. Because injections points rely on CondVar, that per se creates corruption in critical section. So I'm reading this discussion and wonder if CondVar will be fixed in some clever way or I'd better invent new injection point wait mechanism.
>
> Yeah, I was coming to similar conclusions in the reply I just sent:
> we don't really want a policy that we can't put injection-point-based
> delays inside critical sections. So that infrastructure is leaving
> something to be desired.
>
> Having said that, the test script is also doing something we tell
> people not to do, namely SIGKILL the postmaster. Could we use
> SIGQUIT (immediate shutdown) instead?

I'm working backwards from corruptions I see on our production.
And almost always I see stormbringers like OOM, power outage or Debian scripts that (I think) do kill -9 when `service postgresql stop` takes too long.

Best regards, Andrey Borodin.