Verbose builds slow

[John (J5) Palmieri]

On Tue, 2005-10-18 at 16:38 +0100, Ross Burton wrote:
> Hi,
> 
> I just had a heart attack when I re-ran by benchmark and discovered that
> what used to take 3 seconds now takes 9, and when I double the number of
> iterations instead of taking 6 seconds now takes 58.
> 
> After some profiling and compiling by own DBus, I discovered that the
> culprit here is the --enable-verbose flag, which Debian/Ubuntu have
> enabled to get more information when dbus crashes.
> 
> Is the overhead from verbose mode supposed to be O(n^2)?  My benchmark
> is frantically sending string arrays over the bus and the profiles show
> that vsprintf() is being called 20% of the time in the daemon.  Should
> using --enable-verbose cause a warning about the performance hit and be
> removed from the Debian packages?
> 
> Ross

Doesn't it already produce a warning?  If not it should.  And yes I
think D-Bus is at the point that in production builds --enable-verbose
should be turned off, though for unstable builds it should be turned on.
If it is not noticeable right now (besides in your tests) I wouldn't
worry about it and just inform whoever takes care of the Debian packages
to turn it off in the next release.  

-- 
John (J5) Palmieri <johnp at redhat.com>