Re: [PATCH] The alternate Posix timers patch7

[Jim Houston]

Mika Penttilä wrote:
> 
> Just out of curiosity, how does the "sharing the local APIC timer" work
> with the SMP local APIC timer scheme. Hopefully not disable periodic
> timer tick on that cpu totally...?
> 
> --Mika

Hi Mike,

Here is how I wire into the timer interrupt:

   inline void smp_local_timer_interrupt(struct pt_regs * regs)
   {
        int cpu = smp_processor_id();
 
	if (!run_posix_timers((void *)regs))
                return;
        ... the original code continues.

I keep an in kernel Posix style timer queued for each cpu at
HZ frequency.  If this timer has expired run_posix_timers returns
true and the normal local timer processing is done.

The code is not perfect yet.  I don't honour changes in the 
profiling multiplier.

Jim Houston - Concurrent Computer Corp.