On 16.02.2023 18:29, Stefano Garzarella wrote: > On Mon, Feb 06, 2023 at 07:06:32AM +0000, Arseniy Krasnov wrote: >> To use this option pass '--zc' parameter: > > --zerocopy or --zero-copy maybe better follow what we did with the other parameters :-) > >> >> ./vsock_perf --zc --sender <cid> --port <port> --bytes <bytes to send> >> >> With this option MSG_ZEROCOPY flag will be passed to the 'send()' call. >> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx> >> --- >> tools/testing/vsock/vsock_perf.c | 127 +++++++++++++++++++++++++++++-- >> 1 file changed, 120 insertions(+), 7 deletions(-) >> >> diff --git a/tools/testing/vsock/vsock_perf.c b/tools/testing/vsock/vsock_perf.c >> index a72520338f84..1d435be9b48e 100644 >> --- a/tools/testing/vsock/vsock_perf.c >> +++ b/tools/testing/vsock/vsock_perf.c >> @@ -18,6 +18,8 @@ >> #include <poll.h> >> #include <sys/socket.h> >> #include <linux/vm_sockets.h> >> +#include <sys/mman.h> >> +#include <linux/errqueue.h> >> >> #define DEFAULT_BUF_SIZE_BYTES (128 * 1024) >> #define DEFAULT_TO_SEND_BYTES (64 * 1024) >> @@ -28,9 +30,14 @@ >> #define BYTES_PER_GB (1024 * 1024 * 1024ULL) >> #define NSEC_PER_SEC (1000000000ULL) >> >> +#ifndef SOL_VSOCK >> +#define SOL_VSOCK 287 >> +#endif > > I thought we use the current kernel headers when we compile the tests, > do we need to fix something in the makefile? Not sure, of course we are using uapi. But i see, that defines like SOL_XXX is not defined in uapi headers. For example SOL_IP is defined in include/linux/socket.h, but userspace app uses SOL_IP from in.h (at least on my machine). E.g. SOL_XXX is not exported to user. > >> + >> static unsigned int port = DEFAULT_PORT; >> static unsigned long buf_size_bytes = DEFAULT_BUF_SIZE_BYTES; >> static unsigned long vsock_buf_bytes = DEFAULT_VSOCK_BUF_BYTES; >> +static bool zerocopy; >> >> static void error(const char *s) >> { >> @@ -247,15 +254,74 @@ static void run_receiver(unsigned long rcvlowat_bytes) >> close(fd); >> } >> >> +static void recv_completion(int fd) >> +{ >> + struct sock_extended_err *serr; >> + char cmsg_data[128]; >> + struct cmsghdr *cm; >> + struct msghdr msg; >> + int ret; >> + >> + msg.msg_control = cmsg_data; >> + msg.msg_controllen = sizeof(cmsg_data); >> + >> + ret = recvmsg(fd, &msg, MSG_ERRQUEUE); >> + if (ret == -1) >> + return; >> + >> + cm = CMSG_FIRSTHDR(&msg); >> + if (!cm) { >> + fprintf(stderr, "cmsg: no cmsg\n"); >> + return; >> + } >> + >> + if (cm->cmsg_level != SOL_VSOCK) { >> + fprintf(stderr, "cmsg: unexpected 'cmsg_level'\n"); >> + return; >> + } >> + >> + if (cm->cmsg_type) { >> + fprintf(stderr, "cmsg: unexpected 'cmsg_type'\n"); >> + return; >> + } >> + >> + serr = (void *)CMSG_DATA(cm); >> + if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) { >> + fprintf(stderr, "serr: wrong origin\n"); >> + return; >> + } >> + >> + if (serr->ee_errno) { >> + fprintf(stderr, "serr: wrong error code\n"); >> + return; >> + } >> + >> + if (zerocopy && (serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED)) >> + fprintf(stderr, "warning: copy instead of zerocopy\n"); >> +} >> + >> +static void enable_so_zerocopy(int fd) >> +{ >> + int val = 1; >> + >> + if (setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &val, sizeof(val))) >> + error("setsockopt(SO_ZEROCOPY)"); >> +} >> + >> static void run_sender(int peer_cid, unsigned long to_send_bytes) >> { >> time_t tx_begin_ns; >> time_t tx_total_ns; >> size_t total_send; >> + time_t time_in_send; >> void *data; >> int fd; >> >> - printf("Run as sender\n"); >> + if (zerocopy) >> + printf("Run as sender MSG_ZEROCOPY\n"); >> + else >> + printf("Run as sender\n"); >> + >> printf("Connect to %i:%u\n", peer_cid, port); >> printf("Send %lu bytes\n", to_send_bytes); >> printf("TX buffer %lu bytes\n", buf_size_bytes); >> @@ -265,25 +331,58 @@ static void run_sender(int peer_cid, unsigned long to_send_bytes) >> if (fd < 0) >> exit(EXIT_FAILURE); >> >> - data = malloc(buf_size_bytes); >> + if (zerocopy) { >> + enable_so_zerocopy(fd); >> >> - if (!data) { >> - fprintf(stderr, "'malloc()' failed\n"); >> - exit(EXIT_FAILURE); >> + data = mmap(NULL, buf_size_bytes, PROT_READ | PROT_WRITE, >> + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); >> + if (data == MAP_FAILED) { >> + perror("mmap"); >> + exit(EXIT_FAILURE); >> + } >> + } else { >> + data = malloc(buf_size_bytes); >> + >> + if (!data) { >> + fprintf(stderr, "'malloc()' failed\n"); >> + exit(EXIT_FAILURE); >> + } >> } > > Eventually to simplify the code I think we can use the mmaped buffer in > both cases. > >> >> memset(data, 0, buf_size_bytes); >> total_send = 0; >> + time_in_send = 0; >> tx_begin_ns = current_nsec(); >> >> while (total_send < to_send_bytes) { >> ssize_t sent; >> + size_t rest_bytes; >> + time_t before; >> + >> + rest_bytes = to_send_bytes - total_send; >> >> - sent = write(fd, data, buf_size_bytes); >> + before = current_nsec(); >> + sent = send(fd, data, (rest_bytes > buf_size_bytes) ? >> + buf_size_bytes : rest_bytes, >> + zerocopy ? MSG_ZEROCOPY : 0); >> + time_in_send += (current_nsec() - before); >> >> if (sent <= 0) >> error("write"); >> >> + if (zerocopy) { >> + struct pollfd fds = { 0 }; >> + >> + fds.fd = fd; > > Which event are we waiting for here? > >> + >> + if (poll(&fds, 1, -1) < 0) { >> + perror("poll"); >> + exit(EXIT_FAILURE); >> + } > > We need this because we use only one buffer, but if we use more than > one, we could take full advantage of zerocopy, right? > > Otherwise, I don't think it's a fair comparison with non-zerocopy. Yes or course, in next versions i'll update this test for using more long iovs. > > Thanks, > Stefano > >> + >> + recv_completion(fd); >> + } >> + >> total_send += sent; >> } >> >> @@ -294,9 +393,14 @@ static void run_sender(int peer_cid, unsigned long to_send_bytes) >> get_gbps(total_send * 8, tx_total_ns)); >> printf("total time in 'write()': %f sec\n", >> (float)tx_total_ns / NSEC_PER_SEC); >> + printf("time in send %f\n", (float)time_in_send / NSEC_PER_SEC); >> >> close(fd); >> - free(data); >> + >> + if (zerocopy) >> + munmap(data, buf_size_bytes); >> + else >> + free(data); >> } >> >> static const char optstring[] = ""; >> @@ -336,6 +440,11 @@ static const struct option longopts[] = { >> .has_arg = required_argument, >> .val = 'R', >> }, >> + { >> + .name = "zc", >> + .has_arg = no_argument, >> + .val = 'Z', >> + }, >> {}, >> }; >> >> @@ -351,6 +460,7 @@ static void usage(void) >> " --help This message\n" >> " --sender <cid> Sender mode (receiver default)\n" >> " <cid> of the receiver to connect to\n" >> + " --zc Enable zerocopy\n" >> " --port <port> Port (default %d)\n" >> " --bytes <bytes>KMG Bytes to send (default %d)\n" >> " --buf-size <bytes>KMG Data buffer size (default %d). In sender mode\n" >> @@ -413,6 +523,9 @@ int main(int argc, char **argv) >> case 'H': /* Help. */ >> usage(); >> break; >> + case 'Z': /* Zerocopy. */ >> + zerocopy = true; >> + break; >> default: >> usage(); >> } >> -- >> 2.25.1 >> >