Re: [PATCH] check kernel version for io_method

From: Andreas Karlsson <andreas(at)proxel(dot)se>
Sent: Wednesday, January 14, 2026 15:27
To: Steven Niu <niushiji(at)gmail(dot)com>; Pierre <pierre(dot)forstmann(at)gmail(dot)com>; pgsql-hackers(at)lists(dot)postgresql(dot)org <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: [PATCH] check kernel version for io_method

On 1/14/26 8:22 AM, Steven Niu wrote:
> I agree that you are correct for now. But in future, the IoMethod may have new member. Then we have to process it.
>
> How about change to like this:
>   + #else
>   +     if (*newval == IOMETHOD_IO_URING)
>   +     {
>   +             GUC_check_errdetail("io_uring not enabled.");
>   +             return false;
>   +     }

No, that would be incorrect. It would not even compile.
IOMETHOD_IO_URING is not even defined if we do not compile with liburing
enabled. You can try it out yourself by compiling PostgreSQL without
io_uring support and then try to enable it. You will get an error and
that code will never be reached.

Andreas

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Yes, you are definitely correct.
I'd like to withdwar my proposal.