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* [sup-talk] ruby/sup causing lots of wakeups-from-idle
@ 2007-11-12  0:49 Phil Snowberger
  2007-11-12  1:24 ` William Morgan
  0 siblings, 1 reply; 3+ messages in thread
From: Phil Snowberger @ 2007-11-12  0:49 UTC (permalink / raw)


I was wondering if anybody else has a problem with sup/ruby causing
lots of wakeups-from-idle?  The following line comes from the output
of powertop on my thinkpad:

...
  20.6% ( 94.8)              ruby : do_nanosleep (hrtimer_wakeup)
...

That is, there are ~94.8 wakeups-from-idle per second occuring because
ruby is do_nanosleep'ing a lot.  Is there any workaround for this?
Cursory searching seems to indicate that lots of wakeups can be caused
by doing usleep()s instead of select()/poll().  I'm trying to save as
much battery power as possible, and I currently leave sup off until I
want to check my email, which introduces startup time, etc.

I could just run it on some other host and access it with ssh, but for
a few reasons (mostly not wanting to do X forwarding), I'd like to try
getting ruby/sup to behave a little better.

Thanks,
--Phil


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [sup-talk] ruby/sup causing lots of wakeups-from-idle
  2007-11-12  0:49 [sup-talk] ruby/sup causing lots of wakeups-from-idle Phil Snowberger
@ 2007-11-12  1:24 ` William Morgan
  2007-11-13 20:26   ` Phil Snowberger
  0 siblings, 1 reply; 3+ messages in thread
From: William Morgan @ 2007-11-12  1:24 UTC (permalink / raw)


Excerpts from Phil Snowberger's message of Sun Nov 11 16:49:55 -0800 2007:
> I was wondering if anybody else has a problem with sup/ruby causing
> lots of wakeups-from-idle?

Does this happen with other multithreaded Ruby apps? Sup uses select()
for input, and the only persistent threads have multi-second sleep
times. But I have no idea how that translates down to the OS level, as
Ruby does its own threading.

-- 
William <wmorgan-sup at masanjin.net>


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [sup-talk] ruby/sup causing lots of wakeups-from-idle
  2007-11-12  1:24 ` William Morgan
@ 2007-11-13 20:26   ` Phil Snowberger
  0 siblings, 0 replies; 3+ messages in thread
From: Phil Snowberger @ 2007-11-13 20:26 UTC (permalink / raw)


On Nov 11, 2007 8:24 PM, William Morgan <wmorgan-sup at masanjin.net> wrote:
> Excerpts from Phil Snowberger's message of Sun Nov 11 16:49:55 -0800 2007:
> > I was wondering if anybody else has a problem with sup/ruby causing
> > lots of wakeups-from-idle?
>
> Does this happen with other multithreaded Ruby apps? Sup uses select()
> for input, and the only persistent threads have multi-second sleep
> times. But I have no idea how that translates down to the OS level, as
> Ruby does its own threading.

I tried raggle to see if it would cause a similar amount of wakeups,
and it does;  Once it settles into a steady state (after it's checked
each feed on startup), it does ~95 wakeups per second, just like sup.

Sorry for what appears to be a false alarm; I'll take this question to
some ruby folks.

Thanks,
--Phil


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2007-11-13 20:26 UTC | newest]

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