Hello.
Tony Breeds wrote:
Signed-off-by: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>
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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