[PATCH] time: jiffies.c: fix typos in comment

[PATCH] time: jiffies.c: fix typos in comment

[Serafeim Zanikolas]

Signed-off-by: Serafeim Zanikolas <sez@debian.org>
---
 kernel/time/jiffies.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 5404a84..12ba9a7 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -30,8 +30,8 @@
  * the timer interrupt frequency HZ and it suffers
  * inaccuracies caused by missed or lost timer
  * interrupts and the inability for the timer
- * interrupt hardware to accuratly tick at the
- * requested HZ value. It is also not reccomended
+ * interrupt hardware to accurately tick at the
+ * requested HZ value. It is also not recommended
  * for "tick-less" systems.
  */
 #define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
-- 
1.7.1

Re: [PATCH] time: jiffies.c: fix typos in comment

[Thomas Gleixner]

On Sat, 23 Oct 2010, Serafeim Zanikolas wrote:

> 
> Signed-off-by: Serafeim Zanikolas <sez@debian.org>
> ---
>  kernel/time/jiffies.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
> index 5404a84..12ba9a7 100644
> --- a/kernel/time/jiffies.c
> +++ b/kernel/time/jiffies.c
> @@ -30,8 +30,8 @@
>   * the timer interrupt frequency HZ and it suffers
>   * inaccuracies caused by missed or lost timer
>   * interrupts and the inability for the timer
> - * interrupt hardware to accuratly tick at the
> - * requested HZ value. It is also not reccomended
> + * interrupt hardware to accurately tick at the
> + * requested HZ value. It is also not recommended
>   * for "tick-less" systems.

You are not only correcting a typo. You are changing the sense of the
comment, unfortunately in the wrong way.

Why wouldn't it be recommended that the interrupt hardware ticks at
the requested HZ value ? 

The inability of it to tick accurately at the requested HZ value is
one of the causes which make jiffies clocksource inaccurate. And that
what the comment says.

Thanks,

	tglx

Re: [PATCH] time: jiffies.c: fix typos in comment

[Kyle Moffett]

On Sun, Oct 24, 2010 at 10:22, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Sat, 23 Oct 2010, Serafeim Zanikolas wrote:
>> diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
>> index 5404a84..12ba9a7 100644
>> --- a/kernel/time/jiffies.c
>> +++ b/kernel/time/jiffies.c
>> @@ -30,8 +30,8 @@
>>   * the timer interrupt frequency HZ and it suffers
>>   * inaccuracies caused by missed or lost timer
>>   * interrupts and the inability for the timer
>> - * interrupt hardware to accuratly tick at the
>> - * requested HZ value. It is also not reccomended
>> + * interrupt hardware to accurately tick at the
>> + * requested HZ value. It is also not recommended
>>   * for "tick-less" systems.
>
> You are not only correcting a typo. You are changing the sense of the
> comment, unfortunately in the wrong way.
>
> Why wouldn't it be recommended that the interrupt hardware ticks at
> the requested HZ value ?
>
> The inability of it to tick accurately at the requested HZ value is
> one of the causes which make jiffies clocksource inaccurate. And that
> what the comment says.

Thomas,

Please reread the patch again, I think it does exactly what he said it
did.  Specifically, the old text is:
>>   * the timer interrupt frequency HZ and it suffers
>>   * inaccuracies caused by missed or lost timer
>>   * interrupts and the inability for the timer
>>   * interrupt hardware to accuratly tick at the
>>   * requested HZ value. It is also not reccomended
>>   * for "tick-less" systems.

While the new text is:
>>   * the timer interrupt frequency HZ and it suffers
>>   * inaccuracies caused by missed or lost timer
>>   * interrupts and the inability for the timer
>>   * interrupt hardware to accurately tick at the
>>   * requested HZ value. It is also not recommended
>>   * for "tick-less" systems.

I misread it the first time myself, mentally combining the second line
of the old text with the new text; what you probably saw was:

>> - * requested HZ value. It is also not reccomended
>> + * interrupt hardware to accurately tick at the
>> + * requested HZ value.

Cheers,
Kyle Moffett

Re: [PATCH] time: jiffies.c: fix typos in comment

[Thomas Gleixner]

On Sun, 24 Oct 2010, Kyle Moffett wrote:
> Thomas,
> 
> Please reread the patch again, I think it does exactly what he said it
> did.  Specifically, the old text is:
> >>   * the timer interrupt frequency HZ and it suffers
> >>   * inaccuracies caused by missed or lost timer
> >>   * interrupts and the inability for the timer
> >>   * interrupt hardware to accuratly tick at the
> >>   * requested HZ value. It is also not reccomended
> >>   * for "tick-less" systems.
> 
> While the new text is:
> >>   * the timer interrupt frequency HZ and it suffers
> >>   * inaccuracies caused by missed or lost timer
> >>   * interrupts and the inability for the timer
> >>   * interrupt hardware to accurately tick at the
> >>   * requested HZ value. It is also not recommended
> >>   * for "tick-less" systems.
> 
> I misread it the first time myself, mentally combining the second line
> of the old text with the new text; what you probably saw was:
> 
> >> - * requested HZ value. It is also not reccomended
> >> + * interrupt hardware to accurately tick at the
> >> + * requested HZ value.

Crap yes. I read it twice and still failed to parse it correctly.

Thanks,

	tglx