linux-kernel - Re: [PATCH 2/2] time: Cleanup offs_real/wall_to_mono and offs_boot/total_sleep

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Date:	Mon, 23 Jul 2012 12:31:48 -0700
From:	John Stultz <john.stultz@...aro.org>
To:	Ingo Molnar <mingo@...nel.org>
CC:	lkml <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Richard Cochran <richardcochran@...il.com>,
	Prarit Bhargava <prarit@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 2/2] time: Cleanup offs_real/wall_to_mono and offs_boot/total_sleep_time
 updates

On 07/19/2012 02:33 AM, Ingo Molnar wrote:
> * John Stultz <john.stultz@...aro.org> wrote:
>
>> +static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
>> +{
>> +	/* Verify consistency before modifying */
>> +	WARN_ON_ONCE(tk->offs_boot.tv64 !=
>> +				timespec_to_ktime(tk->total_sleep_time).tv64);
> asserts like this can be put into a single line - we rarely need
> to read them if they don't trigger - and making them
> non-intrusive oneliners is a bonus.

Ack.

>>   @@ -456,8 +478,8 @@ int timekeeping_inject_offset(struct timespec *ts)
>>   
>>   
>>   	tk_xtime_add(&timekeeper, ts);
>> -	timekeeper.wall_to_monotonic =
>> -				timespec_sub(timekeeper.wall_to_monotonic, *ts);
>> +	tk_set_wall_to_mono(&timekeeper,
>> +			timespec_sub(timekeeper.wall_to_monotonic, *ts));
> There's a *lot* of unnecessary ugliness here and in many other
> places in kernel/time/ due to repeating patterns of
> "timekeeper.", which gets repeated many times and blows up line
> length.
>
> Please add this to the highest level (system call, irq handler,
> etc.) code:
>
> 	struct timekeeper *tk = &timekeeper;
>
> and pass that down to lower levels. The tk-> pattern will be the
> obvious thing to type in typical time handling functions.
>
> This increases readability and clarifies the data flow and might
> bring other advantages in the future.

Sounds good. Are you ok if this is done in a follow-on patch?

> Stray newline.
>
> I see a pattern with the newlines there - and this isnt the
> first patch from you that has that problem.

Yea, I personally prefer more space between functions, so its a bad 
habit I have (and checkpatch doesn't catch). I'll try to be more 
watchful of it going forward.

thanks
-john


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