Re: redhat debug info - Mailing list pgsql-general

From Joseph S
Subject Re: redhat debug info
Date
Msg-id 460AB117.3030308@selectacast.net
Whole thread Raw
In response to Re: redhat debug info  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: redhat debug info
List pgsql-general
Tom Lane wrote:
> Joseph Shraibman <jks@selectacast.net> writes:
>> Well 1) I'd like to avoid the performance penalty for including debug
>> symbols
>
> There is none.  If there were, it would certainly apply to debuginfo
> as well --- debuginfo is merely moving the symbols over to a different
> file after the compiler finishes.

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.

>
>> and 2) I already built the binary and it is running on a live
>> system, and I'd like to get debug symbols w/o restarting.
>
> You're contradicting yourself.  You are worried in (1) that the
> generated code isn't the same with -g, but in (2) you fantasize
> that you could use the symbols to debug code built without it?

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.
>
> If you're willing to assume that that works, you can build ordinary
> executables with -g and point gdb to them while attaching to the
> existing processes.

Well I know that wouldn't work.

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