Re: Fwd: 8.0 Beta3 worked, RC1 didn't!

Tom Lane wrote:
> Forwarding the attached in case anyone missed it on -general.
>
> The shmem attach address shown in his messages (00DC0000) seems mighty
> low.  What I am suspecting is:
>    1. Postmaster boots, creates shmem, and for some idiotic reason
>       2003 Server creates the shmem segment just above the end of
>       regular memory.
>    2. When subprocesses launch and re-read GUC settings, for one
>       reason or another they use up a little more RAM than the
>       postmaster did.
>    3. Subprocesses fail to attach to shmem because the target
>       address is now in their regular RAM range.
>
> I don't know why 2003 Server has such a brain-dead choice of shmem
> address assignment, nor why listen_addresses might prompt a little extra
> growth of RAM usage.  But the theory seems to fit the available facts.
>
> If this is correct then we have to do something to force a smarter
> choice of shmem address on Windows.  One brute-force way to do it
> might be to malloc a couple hundred K just before the postmaster
> attaches to shmem, and then release?
>
> Theory B is that somehow UsedShmemSegAddr is not being passed down
> accurately in this case, but that seems a mite improbable.

I am confused.  I thought we used a hard-coded location for shared
memory on Win32.

I thought it was 00xDB0000 something but I can't find any mention of
that.  Was it removed?  Are we now starting the postgres.exe binary and
assuming we can map to the same shared memory address as postmaster.exe?

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