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SubjectRe: [PATCH 1/2] timekeeping: add missing non-_ns functions for fast accessors
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On 6/25/19 1:19 AM, Jason A. Donenfeld wrote:
> Previously there was no analogue to get proper ktime_t versions of the
> fast variety of ktime invocations. This commit makes the interface
> uniform with the other accessors.
>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
> Documentation/core-api/timekeeping.rst | 7 +++-
> include/linux/timekeeping.h | 28 ++++++++++++--
> kernel/time/timekeeping.c | 52 +++++++++++++-------------
> 3 files changed, 55 insertions(+), 32 deletions(-)
>

Hi,
There are a few minor documentation problems here. See below.

> diff --git a/Documentation/core-api/timekeeping.rst b/Documentation/core-api/timekeeping.rst
> index 20ee447a50f3..29d38a86faac 100644
> --- a/Documentation/core-api/timekeeping.rst
> +++ b/Documentation/core-api/timekeeping.rst
> @@ -94,7 +94,7 @@ different format depending on what is required by the user:
> down the seconds to the full seconds of the last timer tick
> using the respective reference.
>
> -Coarse and fast_ns access
> +Coarse and fast access
> -------------------------

The "underline ---" length should match the heading length.

>
> Some additional variants exist for more specialized cases:

> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index d911c8470149..db0081a14b90 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c

> @@ -497,47 +496,46 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
> * partially updated. Since the tk->offs_boot update is a rare event, this
> * should be a rare occurrence which postprocessing should be able to handle.
> */
> -u64 notrace ktime_get_boot_fast_ns(void)
> +ktime_t notrace ktime_get_boottime_fast(void)
> {
> struct timekeeper *tk = &tk_core.timekeeper;
>
> - return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
> + return ktime_add(ktime_get_mono_fast(), tk->offs_boot);
> }
> -EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
> +EXPORT_SYMBOL_GPL(ktime_get_boottime_fast);
>
>
> /*
> - * See comment for __ktime_get_fast_ns() vs. timestamp ordering
> + * See comment for __ktime_get_fast() vs. timestamp ordering
> */
> -static __always_inline u64 __ktime_get_real_fast_ns(struct tk_fast *tkf)
> +static __always_inline ktime_t __ktime_get_real_fast(struct tk_fast *tkf)
> {
> struct tk_read_base *tkr;
> unsigned int seq;
> - u64 now;
> + ktime_t now;
>
> do {
> seq = raw_read_seqcount_latch(&tkf->seq);
> tkr = tkf->base + (seq & 0x01);
> - now = ktime_to_ns(tkr->base_real);
> -
> - now += timekeeping_delta_to_ns(tkr,
> + now = ktime_add_ns(tkr->base_real,
> + timekeeping_delta_to_ns(tkr,
> clocksource_delta(
> tk_clock_read(tkr),
> tkr->cycle_last,
> - tkr->mask));
> + tkr->mask)));
> } while (read_seqcount_retry(&tkf->seq, seq));
>
> return now;
> }
>
> /**
> - * ktime_get_real_fast_ns: - NMI safe and fast access to clock realtime.
> + * ktime_get_real_fast: - NMI safe and fast access to clock realtime.

The function name line should not contain a ':' character.
(I know, you didn't change that.)

> */
> -u64 ktime_get_real_fast_ns(void)
> +ktime_t ktime_get_real_fast(void)
> {
> - return __ktime_get_real_fast_ns(&tk_fast_mono);
> + return __ktime_get_real_fast(&tk_fast_mono);
> }
> -EXPORT_SYMBOL_GPL(ktime_get_real_fast_ns);
> +EXPORT_SYMBOL_GPL(ktime_get_real_fast);
>
> /**
> * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource.
>

thnx.
--
~Randy

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