#include <stdlib.h>
#include <string.h>
#include <sys/uio.h>
-#include <sys/utsname.h>
#include <time.h>
#include <unistd.h>
#include <rte_ether.h>
#include <rte_mbuf.h>
#include <rte_pcapng.h>
+#include <rte_reciprocal.h>
#include <rte_time.h>
#include "pcapng_proto.h"
};
/* For converting TSC cycles to PCAPNG ns format */
-struct pcapng_time {
+static struct pcapng_time {
uint64_t ns;
uint64_t cycles;
+ uint64_t tsc_hz;
+ struct rte_reciprocal_u64 tsc_hz_inverse;
} pcapng_time;
-RTE_INIT(pcapng_init)
+static inline void
+pcapng_init(void)
{
struct timespec ts;
pcapng_time.cycles = rte_get_tsc_cycles();
clock_gettime(CLOCK_REALTIME, &ts);
+ pcapng_time.cycles = (pcapng_time.cycles + rte_get_tsc_cycles()) / 2;
pcapng_time.ns = rte_timespec_to_ns(&ts);
+
+ pcapng_time.tsc_hz = rte_get_tsc_hz();
+ pcapng_time.tsc_hz_inverse = rte_reciprocal_value_u64(pcapng_time.tsc_hz);
}
/* PCAPNG timestamps are in nanoseconds */
static uint64_t pcapng_tsc_to_ns(uint64_t cycles)
{
- uint64_t delta;
-
+ uint64_t delta, secs;
+
+ if (!pcapng_time.tsc_hz)
+ pcapng_init();
+
+ /* In essence the calculation is:
+ * delta = (cycles - pcapng_time.cycles) * NSEC_PRE_SEC / rte_get_tsc_hz()
+ * but this overflows within 4 to 8 seconds depending on TSC frequency.
+ * Instead, if delta >= pcapng_time.tsc_hz:
+ * Increase pcapng_time.ns and pcapng_time.cycles by the number of
+ * whole seconds in delta and reduce delta accordingly.
+ * delta will therefore always lie in the interval [0, pcapng_time.tsc_hz),
+ * which will not overflow when multiplied by NSEC_PER_SEC provided the
+ * TSC frequency < approx 18.4GHz.
+ *
+ * Currently all TSCs operate below 5GHz.
+ */
delta = cycles - pcapng_time.cycles;
- return pcapng_time.ns + (delta * NSEC_PER_SEC) / rte_get_tsc_hz();
+ if (unlikely(delta >= pcapng_time.tsc_hz)) {
+ if (likely(delta < pcapng_time.tsc_hz * 2)) {
+ delta -= pcapng_time.tsc_hz;
+ pcapng_time.cycles += pcapng_time.tsc_hz;
+ pcapng_time.ns += NSEC_PER_SEC;
+ } else {
+ secs = rte_reciprocal_divide_u64(delta, &pcapng_time.tsc_hz_inverse);
+ delta -= secs * pcapng_time.tsc_hz;
+ pcapng_time.cycles += secs * pcapng_time.tsc_hz;
+ pcapng_time.ns += secs * NSEC_PER_SEC;
+ }
+ }
+
+ return pcapng_time.ns + rte_reciprocal_divide_u64(delta * NSEC_PER_SEC,
+ &pcapng_time.tsc_hz_inverse);
}
/* length of option including padding */
"%s-%s", dev->bus->name, dev->name);
/* DPDK reports in units of Mbps */
- rte_eth_link_get(port, &link);
- if (link.link_status == ETH_LINK_UP)
+ if (rte_eth_link_get(port, &link) == 0 &&
+ link.link_status == RTE_ETH_LINK_UP)
speed = link.link_speed * PCAPNG_MBPS_SPEED;
if (rte_eth_macaddr_get(port, &macaddr) < 0)