Re: Kernel preemption, yes or no? (was: Filesystem gets a hugeperformance boost)

[Rik van Riel]

On Tue, 17 Apr 2001, Matt Dillon wrote:

>     Under a full load polling would work just as well as an interrupt.
>     With NT for the network tests they hardwired each NIC to a particular
>     CPU.  I don't know if they did any polling or not.

Not true. Interrupts work worse than polling because the interrupt
top halves can keep the CPU busy, whereas with polling you only
peek at the card when you have time.

This means pure interrupts can possibly DoS a CPU (think about a
gigabit ping flood) while polling leaves the box alive and still
allows it to process as much as it can (while not wasting CPU on
taking in packets it cannot process higher up the stack).

regards,

Rik
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