Re: [Tracker] [Strigi-devel] Indexers comparison

[Michal Pryc <Michal Pryc Sun COM>]

Michael Biebl wrote:
> 2007/1/17, jos poortvliet <jos mijnkamer nl>:
>> Op woensdag 17 januari 2007, schreef Jamie McCracken:
>> > Im not so sure - the problem is on some machines using a sustained 100%
>> > cpu can cause laptops to heat up quickly, become more noisy (fans),
>> > drain battery life faster etc
>>
>> well, that would be a reason not to use 100% cpu, but i guess you can
>> use some
>> interface to tell the kernel to use energy-saving mode even tough you're
>> indexing... would be a much better solution than optimizing for
>> laptops...
> 
> While I like trackers unobtrusive way, the point about longer battery
> life is very likely incorrect.
> Having a processor run for 10min at 100% rather than 20min at 50% (or
> even longer as cpufreq enabled kernels will reduce the cpu frequency
> automatically) will most likely save more power, as the kernel can
> enter deeper sleep states.
> Throttling down the indexer process artifically prevents the
> kernel/cpu from doing that.
> 
> I mostly agree with Jamie though. Having noisy fans and hot laptops is
> not great either and you have to  find a compromise somehow.
> Maybe hal could be used to determine if the system is a desktop
> machine or laptop (on battery) and change the behaviour accordingly.

I have to agree with Michael that spending 20 min on indexingh with 50%
will take probably more power than 10min/100%. The other thing is hard
drive which is spinning much longer during 20min than 10 and also is
power consuming. But to be honest I did not thought from this point of
view, great point! The charts shows the CPU utilisation without other
heavy running tasks. The other thing is about "user feeling" which can
not be measured, because it depends on various things. For example
someone who don't know that `nice` exists will run xmms or mplayer which
might have the same priority that beagle or strigi does (I don't know
why trackerd is using priority 34/35??), so during watching the movie or
listening to the music and running 30 other applications normal user,
would like to run the system with indexer almost without noticing that
something is running.Another use case is to left computer for the night
to index all the things, than we would like to run everything using as
much resources as possible. So this is quite interesting thing to
discuss, what resources should *ideal* indexer uses and what choices for
the user should be left.

-- 
best
Michal Pryc