s390/smp: save timestamp on external calls
authorHeiko Carstens <heiko.carstens@de.ibm.com>
Tue, 8 Dec 2015 13:10:12 +0000 (14:10 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 18 Dec 2015 13:59:31 +0000 (14:59 +0100)
commit3dbc78d3a179d99611111d2d86d4283f1f4f82b4
tree7a3bd42badb069791b161b3ef8514b9ea7c8a6bf
parente527aec434b59745654d3b34a3aa7ce3392a85a5
s390/smp: save timestamp on external calls

This is supposed to make debugging easier: if within a dump we can see
that an external call or emergency signal IPI is pending but all cpus
are idle, we have no idea for how long the interrupt is outstanding.

Therefore save a timestamp into the per cpu pcpu array of the target
cpu whenever such an IPI is sent.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/kernel/smp.c