eal: roundup TSC frequency when estimating

When estimating tsc frequency using sleep/gettime round it up to the
nearest multiple of 10Mhz for more accuracy.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Reviewed-by: Keith Wiles <keith.wiles@intel.com>

diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/common/eal_common_timer.c
index dcf26bf..68d67e6 100644 (file)
--- a/lib/librte_eal/common/eal_common_timer.c
+++ b/lib/librte_eal/common/eal_common_timer.c
@@ -64,12 +64,14 @@ rte_get_tsc_hz(void)
 static uint64_t
 estimate_tsc_freq(void)
 {
+#define CYC_PER_10MHZ 1E7
        RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
                " - clock timings may be less accurate.\n");
        /* assume that the sleep(1) will sleep for 1 second */
        uint64_t start = rte_rdtsc();
        sleep(1);
-       return rte_rdtsc() - start;
+       /* Round up to 10Mhz. 1E7 ~ 10Mhz */
+       return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ);
 }
 
 void

diff --git a/lib/librte_eal/linux/eal/eal_timer.c b/lib/librte_eal/linux/eal/eal_timer.c
index bc8f051..76ec170 100644 (file)
--- a/lib/librte_eal/linux/eal/eal_timer.c
+++ b/lib/librte_eal/linux/eal/eal_timer.c
@@ -232,6 +232,7 @@ get_tsc_freq(void)
 {
 #ifdef CLOCK_MONOTONIC_RAW
 #define NS_PER_SEC 1E9
+#define CYC_PER_10MHZ 1E7
 
        struct timespec sleeptime = {.tv_nsec = NS_PER_SEC / 10 }; /* 1/10 second */
 
@@ -248,7 +249,8 @@ get_tsc_freq(void)
 
                double secs = (double)ns/NS_PER_SEC;
                tsc_hz = (uint64_t)((end - start)/secs);
-               return tsc_hz;
+               /* Round up to 10Mhz. 1E7 ~ 10Mhz */
+               return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_10MHZ);
        }
 #endif
        return 0;