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Subjectcpu load calculation
Hi there,

We think we might have encountered a problem with the cpu load
calculation in Linux (2.2.x). The current calculation is based on
dividing the jiffies to user, system and idle jiffies according to the
process the timer hardware interrupt interrupts.

In our case the timer interrupt generates some kernel processing in the
bottom half. After that finishes, the idle process takes over.

The system therefore seems completely idle while in actuality if the
kernel processing takes 50% of a jiffie the system is 50% loaded (with
system processing).

The problem obviously results from synchronization of processing with
the timer interrupt used to calculate the load.

- Did anybody encounter this problem?
- Know any solutions?
- Recommend any specific solution?

Many thanks,
Gilad.

--
Gilad Ben-Yossef <gilad@benyossef.com>
http://benyossef.com :: +972(54)756701
"Anything that can go wrong, will go wrong, while interrupts are disabled. "
-- Murphey's law of kernel programing.

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