lkml.org 
[lkml]   [2015]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 12/12] clocksource: Add some debug info about clocksources being registered
From
On Sat, Mar 7, 2015 at 1:50 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * John Stultz <john.stultz@linaro.org> wrote:
>
>> Print the mask, max_cycles, and max_idle_ns values for clocksources
>> being registered.
>>
>> Cc: Dave Jones <davej@codemonkey.org.uk>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Richard Cochran <richardcochran@gmail.com>
>> Cc: Prarit Bhargava <prarit@redhat.com>
>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>> ---
>> kernel/time/clocksource.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
>> index 3f24bb3..9b75316 100644
>> --- a/kernel/time/clocksource.c
>> +++ b/kernel/time/clocksource.c
>> @@ -697,6 +697,10 @@ void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq)
>
> So that name should really be something like __clocksource_update_freq_scale(),
> right?

Sure, I can add an extra patch to address that...


>> cs->max_idle_ns = clocks_calc_max_nsecs(cs->mult, cs->shift,
>> cs->maxadj, cs->mask,
>> &cs->max_cycles);
>> +
>> + pr_info("clocksource %s: mask: 0x%llx max_cycles: 0x%llx, max_idle_ns: %lld ns\n",
>> + cs->name, cs->mask, cs->max_cycles, cs->max_idle_ns);
>> +
>
> Also, why is this function exported? No in-tree module uses it.

So, its mostly due to the fact that the inline function
__clocksource_updatefreq_hz() in clocksource.h uses it, which may be
used by some clocksources in their enable() hooks. And those
clocksources may be compiled as a module.


> Also, when I read the code, I noticed:
>
> /**
> * __clocksource_updatefreq_scale - Used update clocksource with new freq
> * @cs: clocksource to be registered
> * @scale: Scale factor multiplied against freq to get clocksource hz
> * @freq: clocksource frequency (cycles per second) divided by scale
> *
> * This should only be called from the clocksource->enable() method.
> *
> * This *SHOULD NOT* be called directly! Please use the
> * clocksource_updatefreq_hz() or clocksource_updatefreq_khz helper functions.
>
> One more reason to not export it?
>
> Also, typo in the description.
>
> Plus, one helper function is marked with '()', the other not ...

I'll address that in the new patch as well.

thanks
-john


\
 
 \ /
  Last update: 2015-03-12 04:21    [W:0.084 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site