Horton

Re: OK, so culicidae is *still* broken

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Craig Ringer <craig@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-04-24T18:50:29Z
Lists: pgsql-hackers 
On 2017-04-24 14:43:11 -0400, Tom Lane wrote:
> (We have accepted that kind of overhead for DSM segments, but the
> intention I think is to allow only very trivial data structures in
> the DSM segments.  Losing compiler pointer type checking for data
> structures like the lock or PGPROC tables would be horrid.)

The relptr.h infrastructure brings some of the type-checking back, but
it's still pretty painful.  And just as important, it's quite noticeable
performance-wise.  So we have to do it for dynamic shm (until/unless we
go to using threads), but that doesn't mean we should do it for some of
the most performance critical data structures in PG...

- Andres

Commits

  1. Provide a way to control SysV shmem attach address in EXEC_BACKEND builds.

  2. Disable RandomizedBaseAddress on MSVC builds