The xcall(9) manual page says,
xcall provides a mechanism for making ``low priority'' cross calls. The
function to be executed runs on the remote CPU within a thread context,
and not from a software interrupt, so it can ensure that it is not inter-
rupting other code running on the CPU, and so has exclusive access to the
CPU. Keep in mind that unless disabled, it may cause a kernel preemp-
tion.
I take that last sentence to mean that a low-priority cross call *may*
preempt a thread on the remote CPU. Is that correct?
In other words, can we rephrase that, "A low-priority cross call may
preempt a thread running on the remote CPU unless preemption is disabled
on that CPU."
Dave
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David Young
[email protected] Urbana, IL (217) 721-9981
