Hello.
Tony Breeds wrote:
> Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
I don't see my own signoff or at least a reference to my prior work in
this patch or even at -rt patch -- despite this code ha clearly borrowed from
it. And I'm not sure why this crippled version (lacking 40x/ Book E specific
clockevents implementation) is preferred over mine, unless this implementation
was only aimed at PPC64 machines...
> Index: working/arch/powerpc/Kconfig
> ===================================================================
> --- working.orig/arch/powerpc/Kconfig
> +++ working/arch/powerpc/Kconfig
> @@ -30,6 +30,9 @@ config GENERIC_TIME
> config GENERIC_TIME_VSYSCALL
> def_bool y
>
> +config GENERIC_CLOCKEVENTS
> + def_bool y
> +
> config GENERIC_HARDIRQS
> bool
> default y
Also, have the deterministic CPU accounting incompatibility with
clockevents been dealt with?
> Index: working/arch/powerpc/kernel/time.c
> ===================================================================
> --- working.orig/arch/powerpc/kernel/time.c
> +++ working/arch/powerpc/kernel/time.c
[...]
> @@ -519,10 +541,12 @@ void __init iSeries_time_init_early(void
> void timer_interrupt(struct pt_regs * regs)
> {
> struct pt_regs *old_regs;
> - int next_dec;
> int cpu = smp_processor_id();
> - unsigned long ticks;
> - u64 tb_next_jiffy;
> + struct clock_event_device *evt = &per_cpu(decrementers, cpu);
> +
> + /* Ensure a positive value is written to the decrementer, or else
> + * some CPUs will continuue to take decrementer exceptions */
> + set_dec(DECREMENTER_MAX);
BookE and 40x CPUs don't need this.
> #ifdef CONFIG_PPC32
> if (atomic_read(&ppc_n_lost_interrupts) != 0)
> @@ -532,7 +556,6 @@ void timer_interrupt(struct pt_regs * re
> old_regs = set_irq_regs(regs);
> irq_enter();
>
> - profile_tick(CPU_PROFILING);
> calculate_steal_time();
>
> #ifdef CONFIG_PPC_ISERIES
> @@ -540,44 +563,20 @@ void timer_interrupt(struct pt_regs * re
> get_lppaca()->int_dword.fields.decr_int = 0;
> #endif
>
> - while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu)))
> - >= tb_ticks_per_jiffy) {
> - /* Update last_jiffy */
> - per_cpu(last_jiffy, cpu) += tb_ticks_per_jiffy;
> - /* Handle RTCL overflow on 601 */
> - if (__USE_RTC() && per_cpu(last_jiffy, cpu) >= 1000000000)
> - per_cpu(last_jiffy, cpu) -= 1000000000;
I don't see where the patch removes those variables themselves...
[...]
> - write_seqlock(&xtime_lock);
> - tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
> - if (__USE_RTC() && tb_next_jiffy >= 1000000000)
> - tb_next_jiffy -= 1000000000;
> - if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
> - tb_last_jiffy = tb_next_jiffy;
> - do_timer(1);
> - }
> - write_sequnlock(&xtime_lock);
> - }
Again, where those variables are removed?
> -
> - next_dec = tb_ticks_per_jiffy - ticks;
> - set_dec(next_dec);
> + if (evt->event_handler)
> + evt->event_handler(evt);
> + else
> + evt->set_next_event(DECREMENTER_MAX, evt);
We have already set it to DECREMENTER_MAX at the start of the function.
Please remove the 'else' part...
> @@ -797,6 +796,53 @@ void __init clocksource_init(void)
> clock->name, clock->mult, clock->shift);
> }
>
> +static int decrementer_set_next_event(unsigned long evt,
> + struct clock_event_device *dev)
> +{
> + set_dec(evt);
I'd use (evt - 1) since the interrupt gets generated at 0xffffffff count,
not 0 (on classic CPUs). With you removing of the code that compensated for
the errors, they will accumulate. And no, this wouldn't be enough anyway,
since on 40x and Book E you'll need to set it for evt anyway, since the
interrupt happens at 0 count...
NAK the patch. And I really don't understand why you're throwing alway
already tested/working code...
> + return 0;
> +}
> +
> +static void decrementer_set_mode(enum clock_event_mode mode,
> + struct clock_event_device *dev)
> +{
> + if (mode != CLOCK_EVT_MODE_ONESHOT)
> + decrementer_set_next_event(DECREMENTER_MAX, dev);
> +}
> +
> +static void register_decrementer_clockevent(int cpu)
> +{
> + struct clock_event_device *dec = &per_cpu(decrementers, cpu);
> +
> + *dec = decrementer_clockevent;
> + dec->cpumask = cpumask_of_cpu(cpu);
> +
> + printk(KERN_ERR "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n",
This is a mistake indeed. :-P
WBR, Sergei
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