Re: Self-modifying code - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Self-modifying code
Date
Msg-id 20051216220048.GA28739@surnet.cl
Whole thread Raw
In response to Re: Self-modifying code  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > I just read an article on LWN.net about the usage of self-modifying code
> > for selecting the optimum code for a given operation at run time.
> 
> That went out with hula hoops, I think.  For sure the security
> implications of making your code segment writable mean that the bar for
> "is it worth it" is a WHOLE lot higher than "it might possibly make TAS
> a bit faster".

Actually I was thinking in the issue with defining different sets of TAS
for SMP versus non-SMP.  There was discussion that suggested handing off
two set of binaries, one for each configuration.  So it's not just "it
might possibly" but rather a possible answer to that problem, which was
not mentioned as minor and for which a solution was not found AFAIR.

However it's not something that I'll personally code, so I'll let
somebody else argue about it if they really care about the issue.  I
just felt the need to mention it.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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