Re: [HACKERS] why do shmem attach? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] why do shmem attach?
Date
Msg-id 199909200404.AAA06848@candle.pha.pa.us
Whole thread Raw
In response to why do shmem attach?  (Vadim Mikheev <vadim@krs.ru>)
List pgsql-hackers
[Charset koi8-r unsupported, filtering to ASCII...]
> Exec-on-startup was removed by Bruce long time ago.
> Why we still attach to shmem after fork?

No idea.  I know the shared memory stuff is not copy-on-write for forked
children, so I am not sure why you would have to attach to it.


> Or shmem inheritance is not portable?

If it works on your machine with it removed, commit the change and I can
test it here.   I don't know of any portability problems with shared
memory children.

> Also, all this ShmemIndex stuff seems to be useless
> (except of backend PID lookup but it's for sure
> should be in separate hash table).
> And why separate shmem segment (!!!) is used for 
> Slocks (ipc.c:CreateAndInitSLockMemory(), etc) - they
> use so small amount of memory!

No idea.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
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