[S390] cputime: initialize per thread timer values on fork

Initialize per thread timer values instead of just copying them from
the parent. That way it is easily possible to tell how much time a
thread spent in user/system context.
Doesn't fix a bug, this is just for debugging purposes.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index e0563baa1cfe009f5d43510df2dd72c0a0d3696a..e6b480625cb394685803b878147f59e4611f7888 100644 (file)
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -163,6 +163,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
                unsigned long unused,
                struct task_struct *p, struct pt_regs *regs)
 {
+       struct thread_info *ti;
        struct fake_frame
        {
                struct stack_frame sf;
@@ -214,6 +215,10 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
        p->thread.mm_segment = get_fs();
        /* Don't copy debug registers */
        memset(&p->thread.per_info, 0, sizeof(p->thread.per_info));
+       /* Initialize per thread user and system timer values */
+       ti = task_thread_info(p);
+       ti->user_timer = 0;
+       ti->system_timer = 0;
        return 0;
 }