Re: jiffie
On Sun, Dec 05, 2004 at 03:43:05PM +0100, Paul Akkermans wrote:
> Can anybody tell me what a jiffie is? I've been seeing this term all through the kernel code.
I found this on the net:
> Under Linux the jiffies variable is the number of clock ticks since the
> machine boot. It's rate is defined by (surprise, surprise...) the HZ define
> from the kernel param.h
>
> For a normal (as in - not patched) Linux kernel of versions 2.4.x the value
> of HZ is 100 for the x86 platform and a 1000 for the PowerPC platform. Since
> version 2.6 the x86 port also has a value of 1000 for HZ by default. Patches
> exist to make these variable during compile time.
>
> One issue that is very important to consider is "jiffie warp". The jiffie is
> a 32 bit value, which means it will wrap around somewhere after a year for
> kernel 2.4/x86 and much sooner for 2.6 kernels or on the powerpc.
http://www.mail-archive.com/asterisk-dev@lists.digium.com/msg06930.html
Sam
Reply to:
- References:
- jiffie
- From: "Paul Akkermans" <paulakkermans@wanadoo.nl>