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@xxxxxxxxxxxxxxxx/msg06930.html Sam -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
