Merge pull request #86 from kylestanfield/tcpSmallPackets

Add no_delay and no_cork flags to help tcp_stream send small packets

Author: hi-rajat-kumar

common.c

@@ -233,6 +233,13 @@ void set_tcp_tx_delay(int fd, int delay, struct callbacks *cb)
                 PLOG_ERROR(cb, "setsockopt(TCP_TX_DELAY)");
 }
 
+void set_tcp_no_delay(int fd, struct callbacks *cb)
+{
+        int value = true;
+        if (setsockopt(fd, SOL_TCP, TCP_NODELAY, &value, sizeof(value)))
+                PLOG_ERROR(cb, "setsockopt(TCP_NODELAY)");	
+}
+
 void fill_random(char *buf, int size)
 {
         int fd, chunk, done = 0;

common.h

@@ -157,6 +157,7 @@ void set_freebind(int fd, struct callbacks *cb);
 void set_debug(int fd, int onoff, struct callbacks *cb);
 void set_mark(int fd, int mark, struct callbacks *cb);
 void set_tcp_tx_delay(int fd, int delay, struct callbacks *cb);
+void set_tcp_no_delay(int fd, struct callbacks *cb);
 void fill_random(char *buf, int size);
 int do_close(int fd);
 struct addrinfo *copy_addrinfo(const struct addrinfo *);

define_all_flags.c

@@ -72,6 +72,7 @@ struct flags_parser *add_flags_tcp(struct flags_parser *fp)
         DEFINE_FLAG(fp, bool,         pin_numa,       false,  'N', "Pin threads to CPU cores");
 #endif
         DEFINE_FLAG(fp, int,          tcp_tx_delay,   0,      't', "Force usec delay in TCP flows");
+        DEFINE_FLAG(fp, bool,         no_delay,       false,   0,  "Set TCP_NODELAY sockopt on data sockets to disable Nagle's algorithm");
 
         /* Return the updated fp */
         return (fp);
@@ -149,6 +150,7 @@ struct flags_parser *add_flags_tcp_stream(struct flags_parser *fp)
         DEFINE_FLAG(fp, bool,          split_bidir ,    false,    0,  "Bidirectional using separate tx/rx sockets");
         DEFINE_FLAG(fp, bool,          enable_tcp_maerts,    false,   'M', "Enables TCP_MAERTS test (server writes and client reads). It overrides enable_read, and enable_write");
         DEFINE_FLAG(fp, bool,          async_connect,   false,   0,  "use non blocking connect");
+        DEFINE_FLAG(fp, bool,          no_cork,         false,   0,  "Do not set MSG_MORE when sending over data sockets.");
 
         /* Return the updated fp */
         return (fp);

lib.h

@@ -94,6 +94,8 @@ struct options {
         bool skip_rx_copy;
         bool tx_zerocopy;
         bool rx_zerocopy;
+        bool no_delay;
+        bool no_cork;
         bool time_wait;
         double interval;
         long long max_pacing_rate;

socket.c

@@ -61,6 +61,8 @@ static void socket_init_not_established(struct thread *t, int s)
                 if (err)
                         PLOG_ERROR(t->cb, "setsockopt(SO_LINGER)");
         }
+        if (opts->no_delay)
+            set_tcp_no_delay(s, cb);
 }
 
 /*

tcp_stream_main.c

@@ -60,6 +60,8 @@ int main(int argc, char **argv)
                 opts.recv_flags = MSG_TRUNC;
         if (opts.tx_zerocopy)
                 opts.send_flags = MSG_ZEROCOPY;
+        if (!opts.no_cork)
+                opts.send_flags |= MSG_MORE;
 
         flags_parser_dump(fp);
         flags_parser_destroy(fp);