Re: profiling connection overhead

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: profiling connection overhead
Date: 2010-11-24 19:30:47
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

On Wed, Nov 24, 2010 at 1:20 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> I tried configuring oprofile with --callgraph=10 and then running
> oprofile with -c, but it gives kooky looking output I can't interpret.

It looks like the trick is to compile with -fno-omit-frame-pointer.
New profiling run:

27563 10.3470 memset
15162 5.6917 memcpy
13471 5.0569 postgres hash_search_with_hash_value
13465 5.0547 postgres AllocSetAlloc
9513 3.5711 _int_malloc
8729 3.2768 fread
6336 2.3785 do_lookup_x
5788 2.1728 _dl_fixup
4995 1.8751 postgres MemoryContextAllocZero
4978 1.8687 strcmp

Full results, and call graph, attached. The first obvious fact is
that most of the memset overhead appears to be coming from

Robert Haas
The Enterprise PostgreSQL Company

Attachment Content-Type Size
reconnect-callgraph.txt.bz2 application/x-bzip2 34.9 KB
reconnect-opreport.txt.bz2 application/x-bzip2 6.8 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Andres Freund 2010-11-24 19:32:20 Re: profiling connection overhead
Previous Message Gerhard Heift 2010-11-24 18:47:13 Re: profiling connection overhead