From: Helge Deller deller@gmx.de
commit 340233dcc0160aafcce46ca893d1679f16acf409 upstream.
The cr16 interval timers are not synchronized across CPUs, even with just one dual-core CPU. This becomes visible if the machines have a longer uptime.
Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/parisc/kernel/time.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-)
--- a/arch/parisc/kernel/time.c +++ b/arch/parisc/kernel/time.c @@ -249,33 +249,14 @@ void __init time_init(void) static int __init init_cr16_clocksource(void) { /* - * The cr16 interval timers are not syncronized across CPUs on - * different sockets, so mark them unstable and lower rating on - * multi-socket SMP systems. + * The cr16 interval timers are not synchronized across CPUs. */ if (num_online_cpus() > 1 && !running_on_qemu) { - int cpu; - unsigned long cpu0_loc; - cpu0_loc = per_cpu(cpu_data, 0).cpu_loc; - - for_each_online_cpu(cpu) { - if (cpu == 0) - continue; - if ((cpu0_loc != 0) && - (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc)) - continue; - - clocksource_cr16.name = "cr16_unstable"; - clocksource_cr16.flags = CLOCK_SOURCE_UNSTABLE; - clocksource_cr16.rating = 0; - break; - } + clocksource_cr16.name = "cr16_unstable"; + clocksource_cr16.flags = CLOCK_SOURCE_UNSTABLE; + clocksource_cr16.rating = 0; }
- /* XXX: We may want to mark sched_clock stable here if cr16 clocks are - * in sync: - * (clocksource_cr16.flags == CLOCK_SOURCE_IS_CONTINUOUS) */ - /* register at clocksource framework */ clocksource_register_hz(&clocksource_cr16, 100 * PAGE0->mem_10msec);