eal/bsd: use sysctl to get TSC frequency

BSD provides the TSC frequency value through sysctl.

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>

diff --git a/lib/librte_eal/bsdapp/eal/eal_timer.c b/lib/librte_eal/bsdapp/eal/eal_timer.c
index fd800b9..67da167 100644 (file)
--- a/lib/librte_eal/bsdapp/eal/eal_timer.c
+++ b/lib/librte_eal/bsdapp/eal/eal_timer.c
@@ -41,6 +41,8 @@
 #include <sys/mman.h>
 #include <sys/queue.h>
 #include <pthread.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
 #include <errno.h>
 
 #include <rte_common.h>
@@ -241,29 +243,34 @@ rte_eal_hpet_init(int make_default)
 #endif
 
 static int
-set_tsc_freq_from_clock(void)
+set_tsc_freq_from_sysctl(void)
 {
-#ifdef CLOCK_MONOTONIC_RAW
-#define NS_PER_SEC 1E9
+       size_t sz;
+       int tmp;
 
-       struct timespec sleeptime = {.tv_nsec = 5E8 }; /* 1/2 second */
+       sz = sizeof(tmp);
+       tmp = 0;
 
-       struct timespec t_start, t_end;
+       if (sysctlbyname("kern.timecounter.smp_tsc", &tmp, &sz, NULL, 0))
+               RTE_LOG(WARNING, EAL, "%s\n", strerror(errno));
+       else if (tmp != 1)
+               RTE_LOG(WARNING, EAL, "TSC is not safe to use in SMP mode\n");
 
-       if (clock_gettime(CLOCK_MONOTONIC_RAW, &t_start) == 0) {
-               uint64_t ns, end, start = rte_rdtsc();
-               nanosleep(&sleeptime,NULL);
-               clock_gettime(CLOCK_MONOTONIC_RAW, &t_end);
-               end = rte_rdtsc();
-               ns = ((t_end.tv_sec - t_start.tv_sec) * NS_PER_SEC);
-               ns += (t_end.tv_nsec - t_start.tv_nsec);
+       tmp = 0;
 
-               double secs = (double)ns/NS_PER_SEC;
-               eal_tsc_resolution_hz = (uint64_t)((end - start)/secs);
-               return 0;
+       if (sysctlbyname("kern.timecounter.invariant_tsc", &tmp, &sz, NULL, 0))
+               RTE_LOG(WARNING, EAL, "%s\n", strerror(errno));
+       else if (tmp != 1)
+               RTE_LOG(WARNING, EAL, "TSC is not invariant\n");
+
+       sz = sizeof(eal_tsc_resolution_hz);
+
+       if (sysctlbyname("machdep.tsc_freq", &eal_tsc_resolution_hz, &sz, NULL, 0)) {
+               RTE_LOG(WARNING, EAL, "%s\n", strerror(errno));
+               return -1;
        }
-#endif
-       return -1;
+
+       return 0;
 }
 
 static void
@@ -277,10 +284,11 @@ set_tsc_freq_fallback(void)
        sleep(1);
        eal_tsc_resolution_hz = rte_rdtsc() - start;
 }
+
 /*
  * This function measures the TSC frequency. It uses a variety of approaches.
  *
- * 1. If kernel provides CLOCK_MONOTONIC_RAW we use that to tune the TSC value
+ * 1. Read the TSC frequency value provided by the kernel
  * 2. If kernel does not provide that, and we have HPET support, tune using HPET
  * 3. Lastly, if neither of the above can be used, just sleep for 1 second and
  * tune off that, printing a warning about inaccuracy of timing
@@ -288,7 +296,7 @@ set_tsc_freq_fallback(void)
 static void
 set_tsc_freq(void)
 {
-       if (set_tsc_freq_from_clock() < 0)
+       if (set_tsc_freq_from_sysctl() < 0)
                set_tsc_freq_fallback();
 
        RTE_LOG(INFO, EAL, "TSC frequency is ~%"PRIu64" KHz\n",