Re: Bug#608247: dpkg-architecture is slow

[Guillem Jover <guillem@debian.org>]

Hi!

On Wed, 2010-12-29 at 17:54:55 +0100, Raphael Hertzog wrote:
> On Wed, 29 Dec 2010, Thorsten Glaser wrote:
> > >Thorsten, can you generate the profiling data on your machine so that we
> > >have a better idea of how it runs for you?
> > 
> > Sure. It’s a VM though, so someone with real hardware might be able
> > to provide “better” data.
> 
> I was expecting that the problem was with slow I/O but that seems unlikely
> on such a setup. The output does not differ much from my own run except
> that it takes several seconds instead of a few milliseconds.
> 
> It seems really that perl is just slow on your setup. The biggest part of
> the time is spent on the main code which does really nothing fancy. Maybe
> accessing %ENV is really slow for some reason... I don't know.

I'd expect the thing to take the most time would be the forks/execs for
“gcc -dumpmachine” and “dpkg --print-architecture”, but those do not
seem to appear visibly in the profiling output. Thorsten, could you
check to time those independently?

Your initial time showed 7s, but the profile shows only 2s, maybe
those 5s went into those two invokations, and the rest as Raphaël said
is just slow perl on your arch?

thanks,
guillem