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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2006-01-14 13:21:03 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-14 18:27:09 -0800
commit1f1c12afe5c3e0ef901eec12dee09df4947462ee (patch)
tree157f01441ef5ddc0810d0bfebca4667c21254529 /arch/s390
parentbcc132651d384ad115a275868effb49c64b348ce (diff)
[PATCH] s390: cputime misaccounting
finish_arch_switch needs to update the user cpu time as well, not just the system cpu time. Otherwise the partial user cpu time of a process that is stored in the lowcore will be (mis-)accounted to the next process. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/time.c2
-rw-r--r--arch/s390/kernel/vtime.c27
2 files changed, 27 insertions, 2 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index b0d8ca8e5ee..7c0fe152a11 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -214,7 +214,7 @@ void account_ticks(struct pt_regs *regs)
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
- account_user_vtime(current);
+ account_tick_vtime(current);
#else
while (ticks--)
update_process_times(user_mode(regs));
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 22a895ecb7a..dfe6f085661 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -32,7 +32,7 @@ DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
-void account_user_vtime(struct task_struct *tsk)
+void account_tick_vtime(struct task_struct *tsk)
{
cputime_t cputime;
__u64 timer, clock;
@@ -76,6 +76,31 @@ void account_user_vtime(struct task_struct *tsk)
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
+void account_vtime(struct task_struct *tsk)
+{
+ cputime_t cputime;
+ __u64 timer;
+
+ timer = S390_lowcore.last_update_timer;
+ asm volatile (" STPT %0" /* Store current cpu timer value */
+ : "=m" (S390_lowcore.last_update_timer) );
+ S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
+
+ cputime = S390_lowcore.user_timer >> 12;
+ S390_lowcore.user_timer -= cputime << 12;
+ S390_lowcore.steal_clock -= cputime << 12;
+ account_user_time(tsk, cputime);
+
+ cputime = S390_lowcore.system_timer >> 12;
+ S390_lowcore.system_timer -= cputime << 12;
+ S390_lowcore.steal_clock -= cputime << 12;
+ account_system_time(tsk, 0, cputime);
+}
+
+/*
+ * Update process times based on virtual cpu times stored by entry.S
+ * to the lowcore fields user_timer, system_timer & steal_clock.
+ */
void account_system_vtime(struct task_struct *tsk)
{
cputime_t cputime;