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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-14 15:36:26 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-14 15:37:26 +0200
commitb86ccca49cd8f22086c1d135ab3051cf48fb1688 (patch)
tree2351a8a7680325262cdef293b624fd997ff226bd /arch/s390
parent88e012856d05a5d00ae80c691fb7aa5adda268d7 (diff)
downloadlwn-b86ccca49cd8f22086c1d135ab3051cf48fb1688.tar.gz
lwn-b86ccca49cd8f22086c1d135ab3051cf48fb1688.zip
[S390] fix idle time accounting
The steal time is calculated by subtracting the time the virtual cpu has been running on a physical cpu from the wall clock time. To make that work all wall time needs to be added to the steal time field first before the virtual cpu time is subtracted. The time between the last clock update and the load of the enabled wait psw needs to be added to the steal_time field as well to make the sum over all cpu accounting numbers match the wall clock. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/vtime.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 694b44374a2b..c0870a61f90f 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -134,6 +134,8 @@ void vtime_start_cpu(void)
/* Account time spent with enabled wait psw loaded as idle time. */
idle_time = S390_lowcore.int_clock - idle->idle_enter;
account_idle_time(idle_time);
+ S390_lowcore.steal_timer +=
+ idle->idle_enter - S390_lowcore.last_update_clock;
S390_lowcore.last_update_clock = S390_lowcore.int_clock;
/* Account system time spent going idle. */