Vaidyanathan Srinivasan wrote: > * Arjan van de Ven <[EMAIL PROTECTED]> [2008-03-28 12:56:13]: > >> Vaidyanathan Srinivasan wrote: >>> Hi Arjan, >>> >>> I have been using powertop to find wakeup events and try to correlate >>> with total interrupts received by the idle system. I want to see the >>> rate of local timer interrupts go down as we optimise the drivers and >>> user-space applications to avoid polling. >>> >>> I observed that powertop shows very low wake-from-idle rate on SMP >>> system and the wake-from-idle rate is very high when all other CPUs are >>> offlined and only CPU0 is operational. I have routed all irqs to CPUs >>> before the experiment. >> powertop shows wakeups *per cpu* ... > > Ok, so the wakeups are averaged out? Total wake-ups divided by current > number of CPUs? > > Another related question is how is wake *from idle* computed, how is > the wakeup of non-idle CPUs and idle CPUs distinguished? >
on new enough kernels, or on CPUs with more than 1 c-state, the idle handlers actually do accounting for this and expose it via /proc and sysfs _______________________________________________ Discuss mailing list [email protected] http://mail.lesswatts.org/mailman/listinfo/discuss
