2003-11-04 12:36:12

by Ihar 'Philips' Filipau

[permalink] [raw]
Subject: [2.4] Are jiffies in jiffies?

Hello!

[ I beleive this is real FAQ - so responding with private e-mails
more appropriate.
ptr("RTFM") != 0 are welcome. ]

jiffies declared in kernel/timer.c.
Name suggests that it is incremented 100 times per second.
LDD2 suggests that it is incremented every 1000/HZ per second.

Is it just name misleading - or I really miss the point?

So to translate this to seconds i need (jiffies*1000/HZ)
and milliseconds are just (jiffies/HZ) then.

Am I right?
I need this for {add,mod}_timer() calls.

--
Ihar 'Philips' Filipau / with best regards from Saarbruecken.
-- _ _ _
"... and for $64000 question, could you get yourself |_|*|_|
vaguely familiar with the notion of on-topic posting?" |_|_|*|
-- Al Viro @ LKML |*|*|*|


2003-11-04 12:52:41

by Tomas Telensky

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Subject: Re: [2.4] Are jiffies in jiffies?


> Hello!
>
> [ I beleive this is real FAQ - so responding with private e-mails
> more appropriate.
> ptr("RTFM") != 0 are welcome. ]
>
> jiffies declared in kernel/timer.c.
> Name suggests that it is incremented 100 times per second.
> LDD2 suggests that it is incremented every 1000/HZ per second.
>
> Is it just name misleading - or I really miss the point?
>
> So to translate this to seconds i need (jiffies*1000/HZ)
> and milliseconds are just (jiffies/HZ) then.

No. seconds are jiffies/HZ.
HZ = Herz = something per second :-)
HZ = something / second => second = something / HZ :-)

Tomas

2003-11-04 13:04:42

by Bernd Petrovitsch

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Subject: Re: [2.4] Are jiffies in jiffies?

On Die, 2003-11-04 at 13:52, Tomas Telensky wrote:
> HZ = Herz = something per second :-)
<nitpick>
It is "Hertz".
</nitpick>

Bernd
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