tree 11fbf5522f332e13f9bfb6cf4552513e4d865003
parent b456d94a9757db54eca4677c1b3a13e7170c9bb3
author Heiko Carstens <heiko.carstens@de.ibm.com> 1306139074 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1306139069 +0200

[S390] pfault: cpu hotplug vs missing completion interrupts

On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor
which in turn will cancel all outstanding pfault requests that have
been issued on that cpu (the same happens with a SIGP cpu reset).

The result is that we end up with uninterruptible processes where
the interrupt that would wake up these processes never arrives.

In order to solve this all processes which wait for a pfault
completion interrupt get woken up after a cpu hot remove. The worst
case that could happen is that they fault again and in turn need to
wait again.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>