Talk:Jiffy (time)
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[edit] 1779?
I removed this:
The origin of the word is unknown, but it is believed to have first appeared in 1779.
how do you know it appeared in 1779, if the origin is unknown? Hotdogger 23:04, 4 February 2007 (UTC)
[edit] Original text from jiffie
The following text used was merged into the 'use in computing' section from jiffie:
A jiffie is a count of the number of clock interrupts that have occurred. It is not an absolute time interval unit, since its duration depends on the clock interrupt frequency of the particular hardware platform under review.
Within the Linux 2.6 operating system kernel, on the Intel i386 platform, a jiffie is 1 ms, or 1/1000th of a second. It is different on other hardware platforms. For example, on Sparc, it is 10 ms.
Jiffies are used to report timing stats for processes in the /proc (pseudo-)filesystem in the Linux kernel.
[edit] Jiffies are no absolute time-value in Linux
As far as i read in the kernel jiffies are dependant on the timer-frequency, which is adjustable. So I suppose to remove any references to exact time-values from the article.
#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ)) #define HZ CONFIG_HZ /* Internal kernel timer frequency */
(Source: kernel/sched.c, line 81, /include/asm-i386/param.h, line 5 - 2.6.20 kernel) It would be nice, if somebody could verify this and then edit the article.
[edit] See also
[edit] External links
- KernelAnalysis-HOWTO-6 (Be aware that HZ has gone from 100 to 1000 since that article was written.)
Simply seeking clarification over the length of a Jiffy offered in the text, as defined in 1981 by Edward Harrison. According to Rudy Rucker's book, "Infinity and the Mind: The Science and Philosophy of the Infinite," copyright 1982, a Jiffy, in quantum mechanics, is roughly equal to 10 to the negative 44 or negative 43rd power. (Paperback, page 320). The author goes on to state that a further discussion of this is also found in Paul Davies, "Other Worlds", (Simon & Schuster, New York, 1980). Omnivata 20:50, 10 May 2006 (UTC)
