These are critical fast paths. Using a segment override instead of an address calculation is reducing overhead. Signed-off-by: Christoph LAmeter --- arch/x86/kernel/nmi_64.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: linux-2.6/arch/x86/kernel/nmi_64.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/nmi_64.c 2007-11-19 15:38:59.522056618 -0800 +++ linux-2.6/arch/x86/kernel/nmi_64.c 2007-11-19 15:40:04.481556226 -0800 @@ -291,7 +291,7 @@ void stop_apic_nmi_watchdog(void *unused */ static DEFINE_PER_CPU(unsigned, last_irq_sum); -static DEFINE_PER_CPU(local_t, alert_counter); +static DEFINE_PER_CPU(int, alert_counter); static DEFINE_PER_CPU(int, nmi_touch); void touch_nmi_watchdog(void) @@ -355,13 +355,13 @@ int __kprobes nmi_watchdog_tick(struct p * Ayiee, looks like this CPU is stuck ... * wait a few IRQs (5 seconds) before doing the oops ... */ - local_inc(&__get_cpu_var(alert_counter)); - if (local_read(&__get_cpu_var(alert_counter)) == 5*nmi_hz) + CPU_INC(get_cpu_var(alert_counter)); + if (CPU_READ(get_cpu_var(alert_counter)) == 5*nmi_hz) die_nmi("NMI Watchdog detected LOCKUP on CPU %d\n", regs, panic_on_timeout); } else { __get_cpu_var(last_irq_sum) = sum; - local_set(&__get_cpu_var(alert_counter), 0); + CPU_WRITE(get_cpu_var(alert_counter), 0); } /* see if the nmi watchdog went off */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/