>>I reall wish this wasn't the case because I would dearly love to be able to
>>have interrupt latency as a benchmark test in lmbench. Are you sure there
>>is no way to do this in software? What if you had some way to generate
>>interrupts essentially continuously?
>
>I can't think of any way it could be done, certainly not sufficiently portably
It' s possible to generate interrupt easily triggering the PCI irq from
edge to level continuosly if I remeber well. So should be pretty easy
write a irq interrupt latency bentchmarking kernel module doing something
similar this:
kernel module
{
volatile check = 0;
gen_pci_irq();
old_time = time_now();
while(volatile check == 0 && !timeout);
print(time_now() - old_time);
}
and the IRQ code should be something like this:
{
volatile check = 1;
}
It' s impossible to measure irq latency from user level.
Andrea[s] Arcangeli
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