diff options
Diffstat (limited to 'src/vppinfra/time.c')
| -rw-r--r-- | src/vppinfra/time.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/vppinfra/time.c b/src/vppinfra/time.c index 770ed8b6807..1626ff4ed38 100644 --- a/src/vppinfra/time.c +++ b/src/vppinfra/time.c @@ -142,17 +142,20 @@ done: f64 os_cpu_clock_frequency (void) { +#if defined (__aarch64__) + /* The system counter increments at a fixed frequency. It is distributed + * to each core which has registers for reading the current counter value + * as well as the clock frequency. The system counter is not clocked at + * the same frequency as the core. */ + u32 hz; + asm volatile ("mrs %0, cntfrq_el0":"=r" (hz)); + return (f64) hz; +#endif f64 cpu_freq; if (clib_cpu_supports_invariant_tsc ()) return estimate_clock_frequency (1e-3); -#if defined (__aarch64__) - u64 tsc; - asm volatile ("mrs %0, CNTFRQ_EL0":"=r" (tsc)); - return (f64) tsc; -#endif - /* First try /sys version. */ cpu_freq = clock_frequency_from_sys_filesystem (); if (cpu_freq != 0) |