diff options
Diffstat (limited to 'arch/s390/kernel/vtime.c')
| -rw-r--r-- | arch/s390/kernel/vtime.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index b9ce650e9e99..c8653435c70d 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -89,17 +89,21 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset) if (smp_cpu_mtid && time_after64(jiffies_64, __this_cpu_read(mt_scaling_jiffies))) { u64 cycles_new[32], *cycles_old; - u64 delta, mult, div; + u64 delta, fac, mult, div; cycles_old = this_cpu_ptr(mt_cycles); if (stcctm5(smp_cpu_mtid + 1, cycles_new) < 2) { + fac = 1; mult = div = 0; for (i = 0; i <= smp_cpu_mtid; i++) { delta = cycles_new[i] - cycles_old[i]; - mult += delta; - div += (i + 1) * delta; + div += delta; + mult *= i + 1; + mult += delta * fac; + fac *= i + 1; } - if (mult > 0) { + div *= fac; + if (div > 0) { /* Update scaling factor */ __this_cpu_write(mt_scaling_mult, mult); __this_cpu_write(mt_scaling_div, div); |