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  • Heiko Carstens's avatar
    [S390] pfault: cpu hotplug vs missing completion interrupts · f2db2e6c
    Heiko Carstens authored
    
    
    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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    f2db2e6c