ping: don't call monotonic_us twice per sending the ping

function                                             old     new   delta
sendping6                                             80      85      +5
sendping4                                            106     111      +5
sendping_tail                                        209     204      -5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 10/-5)               Total: 5 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/ping.c b/networking/ping.c
index bf750d032f08c5b518b3e13c4fbc0acc2ecea008..8f85d3ec2517b8d42adae6483cbe326af46fe636 100644 (file)
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -380,7 +380,8 @@ struct globals {
        uint8_t pattern;
        unsigned tmin, tmax; /* in us */
        unsigned long long tsum; /* in us, sum of all times */
-       unsigned deadline_ms;
+       unsigned cur_us; /* low word only, we don't need more */
+       unsigned deadline_us;
        unsigned timeout;
        unsigned sizeof_rcv_packet;
        char *rcv_packet; /* [datalen + MAXIPLEN + MAXICMPLEN] */
@@ -455,7 +456,7 @@ static void print_stats_and_exit(int junk UNUSED_PARAM)
                        tmax / 1000, tmax % 1000);
        }
        /* if condition is true, exit with 1 -- 'failure' */
-       exit(nrecv == 0 || (G.deadline_ms && nrecv < pingcount));
+       exit(nrecv == 0 || (G.deadline_us && nrecv < pingcount));
 }
 
 static void sendping_tail(void (*sp)(int), int size_pkt)
@@ -467,8 +468,8 @@ static void sendping_tail(void (*sp)(int), int size_pkt)
 
        size_pkt += datalen;
 
-       if (G.deadline_ms) {
-               unsigned n = ((unsigned)monotonic_ms()) - G.deadline_ms;
+       if (G.deadline_us) {
+               unsigned n = G.cur_us - G.deadline_us;
                if ((int)n >= 0)
                        print_stats_and_exit(0);
        }
@@ -517,7 +518,7 @@ static void sendping4(int junk UNUSED_PARAM)
         */
        /*if (datalen >= 4)*/
                /* No hton: we'll read it back on the same machine */
-               *(uint32_t*)&pkt->icmp_dun = monotonic_us();
+               *(uint32_t*)&pkt->icmp_dun = G.cur_us = monotonic_us();
 
        pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, datalen + ICMP_MINLEN);
 
@@ -536,7 +537,7 @@ static void sendping6(int junk UNUSED_PARAM)
        pkt->icmp6_id = myid;
 
        /*if (datalen >= 4)*/
-               *(bb__aliased_uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();
+               *(bb__aliased_uint32_t*)(&pkt->icmp6_data8[4]) = G.cur_us = monotonic_us();
 
        //TODO? pkt->icmp_cksum = inet_cksum(...);
 
@@ -891,7 +892,7 @@ static int common_ping_main(int opt, char **argv)
                        OPT_STRING
                        /* exactly one arg; -v and -q don't mix */
                        "\0" "=1:q--v:v--q",
-                       &pingcount, &str_s, &opt_ttl, &G.deadline_ms, &timeout, &str_I, &str_p
+                       &pingcount, &str_s, &opt_ttl, &G.deadline_us, &timeout, &str_I, &str_p
        );
        if (opt & OPT_s)
                datalen = xatou16(str_s); // -s
@@ -905,9 +906,9 @@ static int common_ping_main(int opt, char **argv)
        }
        if (opt & OPT_p)
                G.pattern = xstrtou_range(str_p, 16, 0, 255);
-       if (G.deadline_ms) {
-               unsigned d = G.deadline_ms < INT_MAX/1000 ? G.deadline_ms : INT_MAX/1000;
-               G.deadline_ms = 1 | ((d * 1000) + monotonic_ms());
+       if (G.deadline_us) {
+               unsigned d = G.deadline_us < INT_MAX/1000000 ? G.deadline_us : INT_MAX/1000000;
+               G.deadline_us = 1 | ((d * 1000000) + monotonic_us());
        }
 
        myid = (uint16_t) getpid();