On 05/17/11 18:28, Mulyadi Santosa wrote: > Hi Chris.... > > On Wed, May 18, 2011 at 03:11, Christopher Harvey > <chris@xxxxxxxxxxxxxxxx> wrote: >> I'm having a hard time finding out by reading documentation and source >> code if a system timer IRQ is supposed to be directed at all cores of a >> processor or if just interrupting one core is enough. > > my take is if we don't use local timer interrupt, then logically > (global timer) should interrupt all cores. > > I came to this understanding after recalling a fact that timer is a > way to trigger rescheduling after a time slice of a task is expired. > SInce we can't assume anything on which core a task is currently > running, then it would be easier if we just send interrupt to all > cores. > > Not sure if you are agree with my deduction above.... > I half agree. The way I see it now, WITHOUT local timers a timer only needs to interrupt one core, and an IPI will interrupt the other. My question is: Does a global timer need to send an interrupt to both cores when local timers are enabled or is a a global timer interrupt on one core combined with the local timers enough? Thanks _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
