Does thread safety give any performance penalties?

[Palle Girgensohn]

Hi!

Please see discussion on postgresql hackers list below. Anyone with better 
knowledge about this might have some input here?

Thanks,
Palle


---------- Forwarded Message ----------
Date: onsdag, maj 11, 2005 00.58.38 -0400
From: Tom Lane <tgl at sss.pgh.pa.us>
To: Bruce Momjian <pgman at candle.pha.pa.us>
Subject: Re: [HACKERS] --enable-thread-safety?

Bruce Momjian <pgman at candle.pha.pa.us> writes:
> Palle Girgensohn wrote:
>> Need a piece of advice here. I'm wrapping up the ports for FreeBSD, and
>> jus  wonder if it is perhaps clever to always add --enable-thread-safety
>> to the  configure args. Is there a big enough penalty for having it off
>> by default,  or can I just have it on always?

> I don't think there is any real penalty in PostgreSQL for having it on.
> I don't know what the operating system overhead is on FreeBSD.

More to the point: the overhead if any is all at the libc level.
If your libc is such that there isn't any penalty for thread support
(perhaps better stated "you pay the overhead whether you want it or
not") then go for it.  I believe this is the case in recent Linuxen,
but I don't know the state of play in BSDen.

			regards, tom lane

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