Re: Performance degradation in trunk

[Evan Huus <eapache () gmail com>]

Alright, so there isn't a clear culprit, but there's a good chance it's the
heuristics for STUN - after 1.8 a conversation lookup was added (r44068),
and that uses a g_hash_table. The only major difference between the two
profiles that I found was a significant increase in calls to
g_hash_table_lookup from the conversation code.

If you don't need STUN decoding, try disabling its heuristic (there's no
preference, but just commenting out the heur_dissector_add call should
work) and see if that improves things.

If that doesn't work I'm not sure what the problem could be.

Evan

PS the new name-resolution code also uses g_hash_tables now, but the call
source is comparatively small next to the conversation code, so I don't
think that's the problem. It may be worth trying a 1.10 build as well
though, just for comparison (since that will have the STUN changes but not
the name-resolution changes).


On Thu, Sep 12, 2013 at 9:40 AM, Anders Broman
<anders.broman () ericsson com>wrote:

> File from tshark 1.8.2
> /Anders
> -----Original Message-----
> From: wireshark-dev-bounces () wireshark org [mailto:
> wireshark-dev-bounces () wireshark org] On Behalf Of Anders Broman
> Sent: den 12 september 2013 14:54
> To: Developer support list for Wireshark
> Subject: Re: [Wireshark-dev] Performance degradation in trunk
>
>
>
> -----Original Message-----
> From: wireshark-dev-bounces () wireshark org [mailto:
> wireshark-dev-bounces () wireshark org] On Behalf Of Evan Huus
> Sent: den 12 september 2013 13:15
> To: balint () balintreczey hu; Developer support list for Wireshark
> Subject: Re: [Wireshark-dev] Performance degradation in trunk
>
> On 2013-09-12, at 5:40 AM, Bálint Réczey <balint () balintreczey hu> wrote:
>
> > > Could they analyze perf results or run git bisect to find the point
> > > when the degradation started?
>
> > Since this is on Ubuntu (which can run valgrind) just use the -p option
> to tools/valgrind-wireshark.sh and it will produce a performance profile.
> Do that for >both builds and we'll have something to work with.
> > Evan
>
> Here's the output from "trunk", how do you get anything useful from it?
> /Anders
>
> > PS I suspect some new heuristic dissector has been introduced, since none
> of the other changes from 1.8 to trunk are likely to have such a
> significant >performance impact.
>
> > Cheers,
> > Balint
> >
> > 2013/9/12 Anders Broman <anders.broman () ericsson com>:
> > > Hi,
> > >
> > > I recently supplied some people with an internal build from recent
> > > trunk and got complaints on performance. Switching back
> > >
> > > To the default Wireshark on the Ubuntu 13.04 system 1.8.2 reading of
> > > a 400M trace file with SIP Diameter etc traffic is more than twice as
> fast.
> > > Regards
> > >
> > > Anders
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