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Re: redhat debug info

From: Joseph S <jks(at)selectacast(dot)net>
To: kleptog(at)svana(dot)org, pgsql-general(at)postgresql(dot)org
Subject: Re: redhat debug info
Date: 2007-03-28 19:41:32
Message-ID: 460AC4EC.7050909@selectacast.net (view raw or flat)
Thread:
Lists: pgsql-general
Martijn van Oosterhout wrote:
> On Wed, Mar 28, 2007 at 02:16:55PM -0400, Joseph S wrote:
>> I thought the performance penalty came from making the executable 
>> bigger, which means the executor has to skip over the debug symbols 
>> somehow, which eats up cpu.  If the symbols are in a different file this 
>> wouldn't apply.
> 
> When running the executable is mmaped into memory. So any extra data in
> the executable has absolutly zero effect.
> 
Good to know.  I'll always compile with debug info from now on.

>> Well I don't really know how debug symbols work.  It seems that maybe 
>> all the debug info is is the source files with some mappling info then 
>> maybe it might.
> 
> No, the info is in the debug info (gdb can't be expected to understand
> the source of every language you might want to debug).

I slipped up a little when typing that.  What I meant to say is that the 
files that are dumped into /usr/src/debug seem to be .c and .h files, 
with one binary file.  If that binary file is a map that matches 
statements in the executable to text in the .c and .h then it could be 
possible for those files to be generated w/o having to recompile the 
executable, but no one here seems to know how to do that, so I'll just 
have to recompile and restart.

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