net: add basic ping/pong type workload support

If you use ioengine=net and then set pingpong=1, fio will operate
in a ping pong type fashion. When the reader receives a package
from the writer, it will return the package to the writer again.
The writer, in turn, will wait for this package before writing
a new package. This makes fio useful for roundrobin measurements
on networks.

The submission latency then measures how long it took to submit
a packet to the local system, while the completion latency is how
long it takes for the package to be received and returned by
the other end.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/engines/net.c b/engines/net.c
index fb554a4808745f278054515b05c62370f36c154c..ff8e9e4a1cd4ab4552ee39620910e26d1d11c1ce 100644 (file)
--- a/engines/net.c
+++ b/engines/net.c
@@ -33,6 +33,7 @@ struct netio_options {
        unsigned int port;
        unsigned int proto;
        unsigned int listen;
        unsigned int port;
        unsigned int proto;
        unsigned int listen;

+       unsigned int pingpong;

 };
 
 struct udp_close_msg {
 };
 
 struct udp_close_msg {


@@ -94,6 +95,12 @@ static struct fio_option options[] = {
                .off1   = offsetof(struct netio_options, listen),
                .help   = "Listen for incoming TCP connections",
        },
                .off1   = offsetof(struct netio_options, listen),
                .help   = "Listen for incoming TCP connections",
        },

+       {
+               .name   = "pingpong",
+               .type   = FIO_OPT_STR_SET,
+               .off1   = offsetof(struct netio_options, pingpong),
+               .help   = "Ping-pong IO requests",
+       },

        {
                .name   = NULL,
        },
        {
                .name   = NULL,
        },


@@ -288,7 +295,7 @@ static int fio_netio_send(struct thread_data *td, struct io_u *io_u)
 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;
 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;

-       int ret, flags = OS_MSG_DONTWAIT;
+       int ret, flags = 0;

 
        do {
                if (o->proto == FIO_TYPE_UDP) {
 
        do {
                if (o->proto == FIO_TYPE_UDP) {


@@ -302,8 +309,8 @@ static int fio_netio_send(struct thread_data *td, struct io_u *io_u)
                         * if we are going to write more, set MSG_MORE
                         */
 #ifdef MSG_MORE
                         * if we are going to write more, set MSG_MORE
                         */
 #ifdef MSG_MORE

-                       if (td->this_io_bytes[DDIR_WRITE] + io_u->xfer_buflen <
-                           td->o.size)
+                       if ((td->this_io_bytes[DDIR_WRITE] + io_u->xfer_buflen <
+                           td->o.size) && !o->pingpong)

                                flags |= MSG_MORE;
 #endif
                        ret = send(io_u->file->fd, io_u->xfer_buf,
                                flags |= MSG_MORE;
 #endif
                        ret = send(io_u->file->fd, io_u->xfer_buf,


@@ -315,8 +322,6 @@ static int fio_netio_send(struct thread_data *td, struct io_u *io_u)
                ret = poll_wait(td, io_u->file->fd, POLLOUT);
                if (ret <= 0)
                        break;
                ret = poll_wait(td, io_u->file->fd, POLLOUT);
                if (ret <= 0)
                        break;

-
-               flags &= ~OS_MSG_DONTWAIT;

        } while (1);
 
        return ret;
        } while (1);
 
        return ret;


@@ -342,7 +347,7 @@ static int fio_netio_recv(struct thread_data *td, struct io_u *io_u)
 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;
 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;

-       int ret, flags = OS_MSG_DONTWAIT;
+       int ret, flags = 0;

 
        do {
                if (o->proto == FIO_TYPE_UDP) {
 
        do {
                if (o->proto == FIO_TYPE_UDP) {


@@ -367,28 +372,26 @@ static int fio_netio_recv(struct thread_data *td, struct io_u *io_u)
                ret = poll_wait(td, io_u->file->fd, POLLIN);
                if (ret <= 0)
                        break;
                ret = poll_wait(td, io_u->file->fd, POLLIN);
                if (ret <= 0)
                        break;

-               flags &= ~OS_MSG_DONTWAIT;

                flags |= MSG_WAITALL;
        } while (1);
 
        return ret;
 }
 
                flags |= MSG_WAITALL;
        } while (1);
 
        return ret;
 }
 

-static int fio_netio_queue(struct thread_data *td, struct io_u *io_u)
+static int __fio_netio_queue(struct thread_data *td, struct io_u *io_u,
+                            enum fio_ddir ddir)

 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;
        int ret;
 
 {
        struct netio_data *nd = td->io_ops->data;
        struct netio_options *o = td->eo;
        int ret;
 

-       fio_ro_check(td, io_u);
-
-       if (io_u->ddir == DDIR_WRITE) {
+       if (ddir == DDIR_WRITE) {

                if (!nd->use_splice || o->proto == FIO_TYPE_UDP ||
                    o->proto == FIO_TYPE_UNIX)
                        ret = fio_netio_send(td, io_u);
                else
                        ret = fio_netio_splice_out(td, io_u);
                if (!nd->use_splice || o->proto == FIO_TYPE_UDP ||
                    o->proto == FIO_TYPE_UNIX)
                        ret = fio_netio_send(td, io_u);
                else
                        ret = fio_netio_splice_out(td, io_u);

-       } else if (io_u->ddir == DDIR_READ) {
+       } else if (ddir == DDIR_READ) {

                if (!nd->use_splice || o->proto == FIO_TYPE_UDP ||
                    o->proto == FIO_TYPE_UNIX)
                        ret = fio_netio_recv(td, io_u);
                if (!nd->use_splice || o->proto == FIO_TYPE_UDP ||
                    o->proto == FIO_TYPE_UNIX)
                        ret = fio_netio_recv(td, io_u);


@@ -405,7 +408,7 @@ static int fio_netio_queue(struct thread_data *td, struct io_u *io_u)
                } else {
                        int err = errno;
 
                } else {
                        int err = errno;
 

-                       if (io_u->ddir == DDIR_WRITE && err == EMSGSIZE)
+                       if (ddir == DDIR_WRITE && err == EMSGSIZE)

                                return FIO_Q_BUSY;
 
                        io_u->error = err;
                                return FIO_Q_BUSY;
 
                        io_u->error = err;


@@ -418,6 +421,28 @@ static int fio_netio_queue(struct thread_data *td, struct io_u *io_u)
        return FIO_Q_COMPLETED;
 }
 
        return FIO_Q_COMPLETED;
 }
 

+static int fio_netio_queue(struct thread_data *td, struct io_u *io_u)
+{
+       struct netio_options *o = td->eo;
+       int ret;
+
+       fio_ro_check(td, io_u);
+
+       ret = __fio_netio_queue(td, io_u, io_u->ddir);
+       if (!o->pingpong || ret != FIO_Q_COMPLETED)
+               return ret;
+
+       /*
+        * For ping-pong mode, receive or send reply as needed
+        */
+       if (td_read(td) && io_u->ddir == DDIR_READ)
+               ret = __fio_netio_queue(td, io_u, DDIR_WRITE);
+       else if (td_write(td) && io_u->ddir == DDIR_WRITE)
+               ret = __fio_netio_queue(td, io_u, DDIR_READ);
+
+       return ret;
+}
+

 static int fio_netio_connect(struct thread_data *td, struct fio_file *f)
 {
        struct netio_data *nd = td->io_ops->data;
 static int fio_netio_connect(struct thread_data *td, struct fio_file *f)
 {
        struct netio_data *nd = td->io_ops->data;