Re: Supporting huge pages on Windows

From: pgsql-hackers-owner(at)postgresql(dot)org
> [mailto:pgsql-hackers-owner(at)postgresql(dot)org] On Behalf Of Andres Freund
> I don't think the errdetail is quite right - OpenProcessToken isn't really
> a syscall, is it? But then it's a common pattern already in wind32_shmem.c...

Yes, "Win32 API function" would be correct, but I followed the existing code...

> > + errdetail("Failed system call was %s.",
> > +"LookupPrivilegeValue")));
>
> Other places in the file actually log the arguments to the function...

The only place is CreateFileMapping. Other places (DuplicateHandle and MapViewOfFileEx) don't log arguments. I guess the original developer thought that size and name arguments to CreateFileMapping() might be useful for troubleshooting.

> Wonder if we should quote "Lock Pages in Memory" or add dashes, to make
> sure it's clear that that's the right?

I saw several Microsoft pages, including a page someone introduced me here, and they didn't quote the user right. I'm comfortable with the current code, but I don't mind if the committer adds some quotation.

> > + flProtect = PAGE_READWRITE | SEC_COMMIT |
> SEC_LARGE_PAGES;
>
> Why don't we just add the relevant flag, instead of overwriting the previous
> contents?

I don't have strong opinion on this...

> Uh - isn't that a behavioural change? Was this discussed?

Yes, I described this in the first mail. Magnus asked about this later and I replied.

Regards
Takayuki Tsunakawa