Re: VM corruption on standby - Mailing list pgsql-hackers

From Andrey Borodin
Subject Re: VM corruption on standby
Date
Msg-id C94A8AF6-92AE-4F1A-B029-81E34DA831F2@yandex-team.ru
Whole thread Raw
In response to Re: VM corruption on standby  (Kirill Reshke <reshkekirill@gmail.com>)
Responses Re: VM corruption on standby
List pgsql-hackers

> On 19 Aug 2025, at 23:23, Kirill Reshke <reshkekirill@gmail.com> wrote:
>
>> We'd probably be best off to get back to the actual bug the
>> thread started with, namely whether we aren't doing the wrong
>> thing with VM-update order of operations.
>>
>>                        regards, tom lane
>
> My understanding is that there is no bug in the VM. At least not in
> [0] test, because it uses an injection point in the CRIT section,
> making the server exit too early.
> So, behaviour with inj point and without are very different.
> The corruption we are looking for has to reproducer (see [1]).

I believe there is a bug with PageIsAllVisible(page) && visibilitymap_clear(). But I cannot prove it with an injection
pointtest. Because injections points rely on CondVar, that per se creates corruption in critical section. So I'm
readingthis discussion and wonder if CondVar will be fixed in some clever way or I'd better invent new injection point
waitmechanism. 


Best regards, Andrey Borodin.


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