softirq remains raised for such tasklet. Old times softirq was processed
once per invocation, in schedule and on syscall exit and this was relatively
harmless. Since softirqs are very weakly moderated, it results in strong
cpu hogging.
With current tasklets this can be fixed only introducing additional
synchronization cost to tasklet schedule. Not good. Better to fix
caller.
If Ingo knows about this, I guess it is already fixed in -rt tasklet
or can be fixed. They are really flexible and extensible:
-rt tasklet cost is so high, that even another thousand of cycles
will remain unnnoticed. :-)
Alexey
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