linux/drivers/s390
Martin Schwidefsky 6377981faf [S390] idle time accounting vs. machine checks
A machine check can interrupt the i/o and external interrupt handler
anytime. If the machine check occurs while the interrupt handler is
waking up from idle vtime_start_cpu can get executed a second time
and the int_clock / async_enter_timer values in the lowcore get
clobbered. This can confuse the cpu time accounting.
To fix this problem two changes are needed. First the machine check
handler has to use its own copies of int_clock and async_enter_timer,
named mcck_clock and mcck_enter_timer. Second the nested execution
of vtime_start_cpu has to be prevented. This is done in s390_idle_check
by checking the wait bit in the program status word.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-17 10:00:15 +02:00
..
block [S390] dasd: fix race between tasklet and dasd_sleep_on 2010-05-12 09:32:26 +02:00
char [S390] zcore: Fix reipl device detection 2010-04-22 17:17:19 +02:00
cio [S390] idle time accounting vs. machine checks 2010-05-17 10:00:15 +02:00
crypto include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
kvm include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
net include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
scsi [SCSI] zfcp: Fix tracing of requests with error status 2010-04-11 13:31:20 -05:00
Makefile [S390] split/move machine check handler code 2009-03-26 15:24:10 +01:00