>tested on x86, and all other arches should work as well, but if an
>architecture has irqs-off assumptions in its switch_to() logic
>it might break. (I havent found any but there may such assumptions.)
The ia64_switch_to() code includes a section that can change a pinned
MMU mapping (when the stack for the new process is in a different
granule from the stack for the old process). The code beyond the ".map"
label in arch/ia64/kernel/entry.S includes the comment:
.map:
rsm psr.ic // interrupts (psr.i) are already
disabled here
I don't think that it would be sufficient to merely add psr.i to this rsm
(and to the ssm 15 lines above). That would leave a window where we could
take an interrupt, but not be sure that the current stack is pinned.
-Tony
