Hi Paul, On Sun, Feb 23, 2014 at 10:38 AM, Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > On Sun, Feb 23, 2014 at 01:20:53AM -0600, Joel Fernandes wrote: >> Hi, >> After reading documentation, I follow that NO_HZ_FULL turns off the >> scheduling-clock interrupt on all except the boot CPU, where as >> NO_HZ_IDLE turns it off on all idle CPUs. >> >> I understand the period scheduling-clock interrupt is required to >> compensate for hardware oscillator drift. I believe that's why >> NO_HZ_FULL keeps it ON on atleast one CPU. That way the drift is >> compensated for. >> >> But, with NO_HZ_IDLE, all CPUs turn off interrupt during idle. Then >> how is the drift accounted for? >> >> CC'ing Paul as well for any guidance, thanks :) > > The clock code fixes things up as needed when the first CPU returns > from idle. Thanks a lot for your reply. It makes sense to me now. Also, thanks for the great talk at LCA. :) regards, -Joel -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
