Re: clockevent questions

["Francis Moreau" <francis.moro@gmail.com>]

Thomas,

On 5/12/07, Thomas Gleixner <tglx@linutronix.de> wrote:
> Well, it ends up in hrtimer_interrupt() and the code there finds out,
> that the next timer is not due right now, so it simply requests the same
> (absolute) time event again, which is processed by the clock events code
> and eventually limited to the max delta of the device again.

My timer is finally using the clockevent subsystem. Below is the
output of '/proc/timer_list':

cat /proc/timer_list
Timer List Version: v0.3
HRTIMER_MAX_CLOCK_BASES: 2
now at 64696544360531 nsecs

cpu: 0
clock 0:
 .index:      0
 .resolution: 1 nsecs
 .get_time:   ktime_get_real
 .offset:     1179151153000000000 nsecs
active timers:
clock 1:
 .index:      1
 .resolution: 1 nsecs
 .get_time:   ktime_get
 .offset:     0 nsecs
active timers:
#0: <c03fde10>, tick_sched_timer, S:01
# expires at 64696546875000 nsecs [in 2514469 nsecs]
 .expires_next   : 64696546875000 nsecs
 .hres_active    : 1
 .nr_events      : 16562163
 .nohz_mode      : 0
 .idle_tick      : 0 nsecs
 .tick_stopped   : 0
 .idle_jiffies   : 0
 .idle_calls     : 0
 .idle_sleeps    : 0
 .idle_entrytime : 0 nsecs
 .idle_sleeptime : 0 nsecs
 .last_jiffies   : 0
 .next_jiffies   : 0
 .idle_expires   : 0 nsecs
jiffies: 16485515


Tick Device: mode:     1
Clock Event Device: hrt
max_delta_ns:   2147483647
min_delta_ns:   1000
mult:           206158430
shift:          32
mode:           3
next_event:     64696546875000 nsecs
set_next_event: hrt_next_event
set_mode:       hrt_timer_setup
event_handler:  hrtimer_interrupt

My question is about the clock resolution field which is equal to 1ns.
How is this possible since my timer's frequency is only 100Mhz ?

My 2 cents, it looks like some tabs are missing when printing the list
of hrtimers of each clock...

Thanks
--
Francis
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