src/patches/suse-2.6.27.31/patches.arch/s390-15-09-idle-accounting.diff

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: kernel: fix idle time accounting
   3 References: bnc#518291,LTC#54879
   4
   5 Symptom:     The idle time reported in /proc/stat is too large
   6 Problem:     The time spent with time ticks disabled is accounted twice,
   7              once by the architecture backend and another time by the
   8              generic timer code.
   9 Solution:    Stop accounting idle time in the generic timer code if
  10              CONFIG_VIRT_CPU_ACCOUNTING is enabled.
  11
  12 Acked-by: John Jolly <jjolly@suse.de>
  13 ---
  14
  15  kernel/time/tick-sched.c |    4 ++++
  16  1 file changed, 4 insertions(+)
  17
  18 Index: linux-sles11/kernel/time/tick-sched.c
  19 ===================================================================
  20 --- linux-sles11.orig/kernel/time/tick-sched.c
  21 +++ linux-sles11/kernel/time/tick-sched.c
  22 @@ -377,7 +377,9 @@ void tick_nohz_restart_sched_tick(void)
  23  {
  24         int cpu = smp_processor_id();
  25         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
  26 +#ifndef CONFIG_VIRT_CPU_ACCOUNTING
  27         unsigned long ticks;
  28 +#endif
  29         ktime_t now;
  30
  31         local_irq_disable();
  32 @@ -399,6 +401,7 @@ void tick_nohz_restart_sched_tick(void)
  33         tick_do_update_jiffies64(now);
  34         cpu_clear(cpu, nohz_cpu_mask);
  35
  36 +#ifndef CONFIG_VIRT_CPU_ACCOUNTING
  37         /*
  38          * We stopped the tick in idle. Update process times would miss the
  39          * time we slept as update_process_times does only a 1 tick
  40 @@ -414,6 +417,7 @@ void tick_nohz_restart_sched_tick(void)
  41                                     jiffies_to_cputime(ticks));
  42                 sub_preempt_count(HARDIRQ_OFFSET);
  43         }
  44 +#endif
  45
  46         touch_softlockup_watchdog();
  47         /*