[Crash-utility] [PATCH] Add -r option to timer

[qiaonuohan]

Hello Dave,

Sorry for late. And I think my last mail is not that clear, so I will
add some explanation here.

And firstly, some answers to your question.

1. offset means the offset of the clock to the monotonic time.

2. If offset is 0 or without offset, the clock gets the monotonic time
with it.

3. If offset is not 0, lick clock 0 on cpu 0, the time of this clock is
monotonic time together with the value of offset. Additionally,
expiration of the clock is also based on the offset.

If I want to compare expiration with current time, I should first add
offset with monotonic time(I use uptime in my command, for accurate time 
is unable to get), then get the current time of the clock.

At 2013-3-2 5:35, Dave Anderson wrote:
>
>
> Hi Qiao,
>
> Clarify this for me -- the offset value for the ktime_get_real() timer is
> presumably the current per-timer clock value for that timer:
>
> cpu: 0  HRTIMER_CPU_BASE: ffff880004159d20
>    clock: 0  HRTIMER_CLOCK_BASE: ffff880004159d28
>      OFFSET:     1277723463192897448
>      GET_TIME:   ktime_get_real
>      ACTIVE TIMERS:
>                        EXPIRES                      HRTIMER           FUNCTION
>        1277723709520405731-1277723709520455731  ffff88001cc71d18  ffffffff81093e00<hrtimer_wakeup>
>
> But what does an offset of 0 mean for ktime_get() timers?
>
>    clock: 1  HRTIMER_CLOCK_BASE: ffff880004159d68
>      OFFSET:     0
>      GET_TIME:   ktime_get
>      ACTIVE TIMERS:
>                  EXPIRES                HRTIMER           FUNCTION
>         205155628339-205156606338   ffff88001dfa1a68  ffffffff81093e00<hrtimer_wakeup>
>         205500000000-205500000000   ffff880004159e20  ffffffff810a0290<tick_sched_timer>
>         212807104852-212807154852   ffff88000355fea8  ffffffff81093e00<hrtimer_wakeup>
>         221875226353-221905226352   ffff880003611a68  ffffffff81093e00<hrtimer_wakeup>
>         237880877947-237880927947   ffff88001df2dea8  ffffffff81093e00<hrtimer_wakeup>
>         254807591647-254877419646   ffff88001d67ba68  ffffffff81093e00<hrtimer_wakeup>
>         347174079293-347174079293   ffff8800035edc68  ffffffff810701a0<it_real_fn>
>
> And for the old-style hrtimers, there is no offset value shown at all.  What would
> their expires values compare to?
>
>    clock: 1  HRTIMER_BASE: ffff810009006500
>      GET_TIME:   ktime_get
>      ACTIVE TIMERS:
>            EXPIRES          HRTIMER           FUNCTION
>        614160200709018  ffff81042e432ab0  ffffffff80095103<it_real_fn>
>        614160235717018  ffff8103d93681b0  ffffffff80095103<it_real_fn>
>
> Dave
>
> --
> Crash-utility mailing list
> Crash-utility at redhat.com
> https://www.redhat.com/mailman/listinfo/crash-utility
>
>


-- 
--
Regards
Qiao Nuohan