Re: Jiffy based timers/timeouts can expire too soon.

[Anton Blanchard]

> Well, hopefully the lost tick detection code won't over compensate, so
> it shouldn't be an issue. However, as Tim Mann pointed out it, due to
> interrupt delay and queuing, it is seen on virtualized systems.

We saw this on ppc64 on earlier 2.6 kernels. There were some bugs with
the VM where interrupts would get disabled for a long time (we saw 20+
second periods). A SCSI timeout would occur on another CPU and at that
time irqs would get reenabled and 20 seconds of time would get replayed.

A bunch of timers would go off early and the SCSI adapter would explode.

Anton
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