comment: block sleep is necessary

diff --git a/pcap-dpdk.c b/pcap-dpdk.c
index a3f8bd5579a85fc169914a93b9d2dd806283da9f..1fcbcd38735e73bc3f74a4f51219b04dbbdbd304 100644 (file)
--- a/pcap-dpdk.c
+++ b/pcap-dpdk.c
@@ -235,7 +235,8 @@ static int dpdk_read_with_timeout(pcap_t *p, uint16_t portid, uint16_t queueid,s
                                if (p->break_loop){
                                        break;
                                }
-                               // sleep for a very short while, but do not block CPU.
+                               // sleep for a very short while.
+                               // block sleep is the only choice, since usleep() will impact performance dramatically.
                                rte_delay_us_block(DPDK_DEF_MIN_SLEEP_MS*1000);
                                sleep_ms += DPDK_DEF_MIN_SLEEP_MS;
                        }