linux-kernel - Re: [RFC patch 4/7] timekeeping: Add NMI safe accessor to mono/boot/real clocks

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Message-ID: <20171117180034.30413b64@gandalf.local.home>
Date:   Fri, 17 Nov 2017 18:00:34 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linus Torvalds <torvalds@...uxfoundation.org>,
        Prarit Bhargava <prarit@...hat.com>,
        Mark Salyzyn <salyzyn@...roid.com>,
        Petr Mladek <pmladek@...e.com>, Ingo Molnar <mingo@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Joe Perches <joe@...ches.com>
Subject: Re: [RFC patch 4/7] timekeeping: Add NMI safe accessor to
 mono/boot/real clocks

On Wed, 15 Nov 2017 19:15:35 +0100
Thomas Gleixner <tglx@...utronix.de> wrote:

> +static notrace u64 __ktime_get_real_fast(struct tk_fast *tkf, u64 *mono)
>  {
>  	struct tk_read_base *tkr;
> +	u64 basem, baser, delta;
>  	unsigned int seq;
> -	u64 now;
>  
>  	do {
>  		seq = raw_read_seqcount_latch(&tkf->seq);
>  		tkr = tkf->base + (seq & 0x01);
> -		now = ktime_to_ns(tkr->base_real);
> +		basem = ktime_to_ns(tkr->base);
> +		baser = ktime_to_ns(tkr->base_real);
>  
> -		now += timekeeping_delta_to_ns(tkr,
> -				clocksource_delta(
> -					tk_clock_read(tkr),
> -					tkr->cycle_last,
> -					tkr->mask));
> +		delta = timekeeping_delta_to_ns(tkr,
> +				clocksource_delta(tk_clock_read(tkr),
> +				tkr->cycle_last, tkr->mask));

Could you indent this better. It looks like timekeeping_delta_to_ns()
takes 4 arguments, when it really only takes two.

		delta = timekeeping_dela_to_ns(tkr,
				clocksource_delta(tk_clock_read(tkr),
					tkr->cycle_last, tkr->mask));

Would point out, at least, that it takes two arguments, and
clocksource_delta() takes three (not one).

-- Steve