diff options
Diffstat (limited to 'kernel/trace/trace_clock.c')
| -rw-r--r-- | kernel/trace/trace_clock.c | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index b588fd81f7f9..878c03f386ba 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -20,6 +20,8 @@ #include <linux/ktime.h> #include <linux/trace_clock.h> +#include "trace.h" + /* * trace_clock_local(): the simplest and least coherent tracing clock. * @@ -28,17 +30,17 @@ */ u64 notrace trace_clock_local(void) { - unsigned long flags; u64 clock; + int resched; /* * sched_clock() is an architecture implemented, fast, scalable, * lockless clock. It is not guaranteed to be coherent across * CPUs, nor across CPU idle events. */ - raw_local_irq_save(flags); + resched = ftrace_preempt_disable(); clock = sched_clock(); - raw_local_irq_restore(flags); + ftrace_preempt_enable(resched); return clock; } @@ -66,10 +68,14 @@ u64 notrace trace_clock(void) * Used by plugins that need globally coherent timestamps. */ -static u64 prev_trace_clock_time; - -static raw_spinlock_t trace_clock_lock ____cacheline_aligned_in_smp = - (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; +/* keep prev_time and lock in the same cacheline. */ +static struct { + u64 prev_time; + raw_spinlock_t lock; +} trace_clock_struct ____cacheline_aligned_in_smp = + { + .lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED, + }; u64 notrace trace_clock_global(void) { @@ -88,19 +94,19 @@ u64 notrace trace_clock_global(void) if (unlikely(in_nmi())) goto out; - __raw_spin_lock(&trace_clock_lock); + __raw_spin_lock(&trace_clock_struct.lock); /* * TODO: if this happens often then maybe we should reset - * my_scd->clock to prev_trace_clock_time+1, to make sure + * my_scd->clock to prev_time+1, to make sure * we start ticking with the local clock from now on? */ - if ((s64)(now - prev_trace_clock_time) < 0) - now = prev_trace_clock_time + 1; + if ((s64)(now - trace_clock_struct.prev_time) < 0) + now = trace_clock_struct.prev_time + 1; - prev_trace_clock_time = now; + trace_clock_struct.prev_time = now; - __raw_spin_unlock(&trace_clock_lock); + __raw_spin_unlock(&trace_clock_struct.lock); out: raw_local_irq_restore(flags); |