@@ -18,6 +18,8 @@
/examples/io_uring-test
/examples/io_uring-udp
/examples/link-cp
+/examples/napi-busy-poll-client
+/examples/napi-busy-poll-server
/examples/ucontext-cp
/examples/poll-bench
/examples/send-zerocopy
@@ -15,6 +15,8 @@ example_srcs := \
io_uring-test.c \
io_uring-udp.c \
link-cp.c \
+ napi-busy-poll-client.c \
+ napi-busy-poll-server.c \
poll-bench.c \
send-zerocopy.c
new file mode 100644
@@ -0,0 +1,451 @@
+#include <ctype.h>
+#include <errno.h>
+#include <float.h>
+#include <getopt.h>
+#include <liburing.h>
+#include <math.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <time.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+
+#define MAXBUFLEN 100
+#define PORTNOLEN 10
+#define ADDRLEN 80
+#define RINGSIZE 1024
+
+#define printable(ch) (isprint((unsigned char)ch) ? ch : '#')
+
+enum {
+ IOURING_RECV,
+ IOURING_SEND,
+ IOURING_RECVMSG,
+ IOURING_SENDMSG
+};
+
+struct ctx
+{
+ struct io_uring ring;
+ struct sockaddr_in6 saddr;
+
+ int sockfd;
+ int buffer_len;
+ int num_pings;
+ bool napi_check;
+
+ union {
+ char buffer[MAXBUFLEN];
+ struct timespec ts;
+ };
+
+ int rtt_index;
+ double *rtt;
+} ctx;
+
+struct options
+{
+ int num_pings;
+ int timeout;
+
+ bool sq_poll;
+ bool busy_loop;
+ bool prefer_busy_poll;
+
+ char port[PORTNOLEN];
+ char addr[ADDRLEN];
+} options;
+
+struct option longopts[] =
+{
+ {"address" , 1, NULL, 'a'},
+ {"busy" , 0, NULL, 'b'},
+ {"help" , 0, NULL, 'h'},
+ {"num_pings", 1, NULL, 'n'},
+ {"port" , 1, NULL, 'p'},
+ {"prefer" , 1, NULL, 'u'},
+ {"sqpoll" , 0, NULL, 's'},
+ {"timeout" , 1, NULL, 't'},
+ {NULL , 0, NULL, 0 }
+};
+
+static void printUsage(const char *name)
+{
+ fprintf(stderr,
+ "Usage: %s [-l|--listen] [-a|--address ip_address] [-p|--port port-no] [-s|--sqpoll]"
+ " [-b|--busy] [-n|--num pings] [-t|--timeout busy-poll-timeout] [-u||--prefer] [-h|--help]\n"
+ "--address\n"
+ "-a : remote or local ipv6 address\n"
+ "--busy\n"
+ "-b : busy poll io_uring instead of blocking.\n"
+ "--num_pings\n"
+ "-n : number of pings\n"
+ "--port\n"
+ "-p : port\n"
+ "--sqpoll\n"
+ "-s : Configure io_uring to use SQPOLL thread\n"
+ "--timeout\n"
+ "-t : Configure NAPI busy poll timeoutn"
+ "--prefer\n"
+ "-u : prefer NAPI busy poll\n"
+ "--help\n"
+ "-h : Display this usage message\n\n",
+ name);
+}
+
+static void printError(const char *msg, int opt)
+{
+ if (msg && opt)
+ fprintf(stderr, "%s (-%c)\n", msg, printable(opt));
+}
+
+static void setProcessScheduler(void)
+{
+ struct sched_param param;
+
+ param.sched_priority = sched_get_priority_max(SCHED_FIFO);
+ if (sched_setscheduler(0, SCHED_FIFO, ¶m) < 0)
+ fprintf(stderr, "sched_setscheduler() failed: (%d) %s\n",
+ errno, strerror(errno));
+}
+
+static double diffTimespec(const struct timespec *time1, const struct timespec *time0)
+{
+ return (time1->tv_sec - time0->tv_sec)
+ + (time1->tv_nsec - time0->tv_nsec) / 1000000000.0;
+}
+
+static uint64_t encodeUserData(char type, int fd)
+{
+ return (uint32_t)fd | ((uint64_t)type << 56);
+}
+
+static void decodeUserData(uint64_t data, char *type, int *fd)
+{
+ *type = data >> 56;
+ *fd = data & 0xffffffffU;
+}
+
+static const char *opTypeToStr(char type)
+{
+ const char *res;
+
+ switch (type) {
+ case IOURING_RECV:
+ res = "IOURING_RECV";
+ break;
+ case IOURING_SEND:
+ res = "IOURING_SEND";
+ break;
+ case IOURING_RECVMSG:
+ res = "IOURING_RECVMSG";
+ break;
+ case IOURING_SENDMSG:
+ res = "IOURING_SENDMSG";
+ break;
+ default:
+ res = "Unknown";
+ }
+
+ return res;
+}
+
+static void reportNapi(struct ctx *ctx)
+{
+ unsigned int napi_id = 0;
+ socklen_t len = sizeof(napi_id);
+
+ getsockopt(ctx->sockfd, SOL_SOCKET, SO_INCOMING_NAPI_ID, &napi_id, &len);
+ if (napi_id)
+ printf(" napi id: %d\n", napi_id);
+ else
+ printf(" unassigned napi id\n");
+
+ ctx->napi_check = true;
+}
+
+static void sendPing(struct ctx *ctx)
+{
+ struct io_uring_sqe *sqe = io_uring_get_sqe(&ctx->ring);
+
+ clock_gettime(CLOCK_REALTIME, (struct timespec *)ctx->buffer);
+
+ io_uring_prep_send(sqe, ctx->sockfd, ctx->buffer, sizeof(struct timespec), 0);
+ sqe->user_data = encodeUserData(IOURING_SEND, ctx->sockfd);
+}
+
+static void receivePing(struct ctx *ctx)
+{
+ struct io_uring_sqe *sqe = io_uring_get_sqe(&ctx->ring);
+
+ io_uring_prep_recv(sqe, ctx->sockfd, ctx->buffer, MAXBUFLEN, 0);
+ sqe->user_data = encodeUserData(IOURING_RECV, ctx->sockfd);
+}
+
+static void recordRTT(struct ctx *ctx)
+{
+ struct timespec startTs = ctx->ts;
+
+ // Send next ping.
+ sendPing(ctx);
+
+ // Store round-trip time.
+ ctx->rtt[ctx->rtt_index] = diffTimespec(&ctx->ts, &startTs);
+ ctx->rtt_index++;
+}
+
+static void printStats(struct ctx *ctx)
+{
+ double minRTT = DBL_MAX;
+ double maxRTT = 0.0;
+ double avgRTT = 0.0;
+ double stddevRTT = 0.0;
+
+ // Calculate min, max, avg.
+ for (int i = 0; i < ctx->rtt_index; i++) {
+ if (ctx->rtt[i] < minRTT)
+ minRTT = ctx->rtt[i];
+ if (ctx->rtt[i] > maxRTT)
+ maxRTT = ctx->rtt[i];
+
+ avgRTT += ctx->rtt[i];
+ }
+ avgRTT /= ctx->rtt_index;
+
+ // Calculate stddev.
+ for (int i = 0; i < ctx->rtt_index; i++)
+ stddevRTT += fabs(ctx->rtt[i] - avgRTT);
+ stddevRTT /= ctx->rtt_index;
+
+ fprintf(stdout, " rtt(us) min/avg/max/mdev = %.3f/%.3f/%.3f/%.3f\n",
+ minRTT * 1000000, avgRTT * 1000000, maxRTT * 1000000, stddevRTT * 1000000);
+}
+
+static int completion(struct ctx *ctx, struct io_uring_cqe *cqe)
+{
+ char type;
+ int fd;
+ int res = cqe->res;
+
+ decodeUserData(cqe->user_data, &type, &fd);
+ if (res < 0) {
+ fprintf(stderr, "unexpected %s failure: (%d) %s\n",
+ opTypeToStr(type), -res, strerror(-res));
+ return -1;
+ }
+
+ switch (type) {
+ case IOURING_SEND:
+ receivePing(ctx);
+ break;
+ case IOURING_RECV:
+ if (res != sizeof(struct timespec)) {
+ fprintf(stderr, "unexpected ping reply len: %d\n", res);
+ abort();
+ }
+
+ if (!ctx->napi_check) {
+ reportNapi(ctx);
+ sendPing(ctx);
+ } else {
+ recordRTT(ctx);
+ }
+
+ --ctx->num_pings;
+ break;
+
+ default:
+ fprintf(stderr, "unexpected %s completion\n",
+ opTypeToStr(type));
+ return -1;
+ break;
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ struct ctx ctx;
+ struct options opt;
+ struct __kernel_timespec *tsPtr;
+ struct __kernel_timespec ts;
+ struct io_uring_params params;
+ struct io_uring_napi napi;
+ int flag;
+
+ memset(&opt, 0, sizeof(struct options));
+
+ // Process flags.
+ while ((flag = getopt_long(argc, argv, ":hsbua:n:p:t:", longopts, NULL)) != -1) {
+ switch (flag) {
+ case 'a':
+ strcpy(opt.addr, optarg);
+ break;
+ case 'b':
+ opt.busy_loop = true;
+ break;
+ case 'h':
+ printUsage(argv[0]);
+ exit(0);
+ break;
+ case 'n':
+ opt.num_pings = atoi(optarg) + 1;
+ break;
+ case 'p':
+ strcpy(opt.port, optarg);
+ break;
+ case 's':
+ opt.sq_poll = true;
+ break;
+ case 't':
+ opt.timeout = atoi(optarg);
+ break;
+ case 'u':
+ opt.prefer_busy_poll = true;
+ break;
+ case ':':
+ printError("Missing argument", optopt);
+ printUsage(argv[0]);
+ exit(-1);
+ break;
+ case '?':
+ printError("Unrecognized option", optopt);
+ printUsage(argv[0]);
+ exit(-1);
+ break;
+
+ default:
+ fprintf(stderr, "Fatal: Unexpected case in CmdLineProcessor switch()\n");
+ exit(-1);
+ break;
+ }
+ }
+
+ if (strlen(opt.addr) == 0) {
+ fprintf(stderr, "address option is mandatory\n");
+ printUsage(argv[0]);
+ exit(1);
+ }
+
+ ctx.saddr.sin6_port = htons(atoi(opt.port));
+ ctx.saddr.sin6_family = AF_INET6;
+
+ if (inet_pton(AF_INET6, opt.addr, &ctx.saddr.sin6_addr) <= 0) {
+ fprintf(stderr, "inet_pton error for %s\n", optarg);
+ printUsage(argv[0]);
+ exit(1);
+ }
+
+ // Connect to server.
+ fprintf(stdout, "Connecting to %s... (port=%s) to send %d pings\n", opt.addr, opt.port, opt.num_pings - 1);
+
+ if ((ctx.sockfd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+ fprintf(stderr, "socket() failed: (%d) %s\n", errno, strerror(errno));
+ exit(1);
+ }
+
+ if (connect(ctx.sockfd, (struct sockaddr *)&ctx.saddr, sizeof(struct sockaddr_in6)) < 0) {
+ fprintf(stderr, "connect() failed: (%d) %s\n", errno, strerror(errno));
+ exit(1);
+ }
+
+ // Setup ring.
+ memset(¶ms, 0, sizeof(params));
+ memset(&ts, 0, sizeof(ts));
+ memset(&napi, 0, sizeof(napi));
+
+ if (opt.sq_poll) {
+ params.flags = IORING_SETUP_SQPOLL;
+ params.sq_thread_idle = 50;
+ }
+
+ if (io_uring_queue_init_params(RINGSIZE, &ctx.ring, ¶ms) < 0) {
+ fprintf(stderr, "io_uring_queue_init_params() failed: (%d) %s\n",
+ errno, strerror(errno));
+ exit(1);
+ }
+
+ if (opt.timeout || opt.prefer_busy_poll) {
+ napi.prefer_busy_poll = opt.prefer_busy_poll;
+ napi.busy_poll_to = opt.timeout;
+
+ io_uring_register_napi(&ctx.ring, &napi);
+ }
+
+ if (opt.busy_loop)
+ tsPtr = &ts;
+ else
+ tsPtr = NULL;
+
+ // Use realtime scheduler.
+ setProcessScheduler();
+
+ // Copy payload.
+ clock_gettime(CLOCK_REALTIME, &ctx.ts);
+
+ // Setup context.
+ ctx.napi_check = false;
+ ctx.buffer_len = sizeof(struct timespec);
+ ctx.num_pings = opt.num_pings;
+
+ ctx.rtt_index = 0;
+ ctx.rtt = (double *)malloc(sizeof(double) * opt.num_pings);
+ if (!ctx.rtt) {
+ fprintf(stderr, "Cannot allocate results array\n");
+ exit(1);
+ }
+
+ // Send initial message to get napi id.
+ sendPing(&ctx);
+
+ while (ctx.num_pings != 0) {
+ int res;
+ unsigned num_completed = 0;
+ unsigned head;
+ struct io_uring_cqe *cqe;
+
+ do {
+ res = io_uring_submit_and_wait_timeout(&ctx.ring, &cqe, 1, tsPtr, NULL);
+ }
+ while (res < 0 && errno == ETIME);
+
+ io_uring_for_each_cqe(&ctx.ring, head, cqe) {
+ ++num_completed;
+ if (completion(&ctx, cqe))
+ goto out;
+ }
+
+ if (num_completed)
+ io_uring_cq_advance(&ctx.ring, num_completed);
+ }
+
+ printStats(&ctx);
+
+out:
+ // Clean up.
+ if (opt.timeout || opt.prefer_busy_poll) {
+ io_uring_unregister_napi(&ctx.ring, &napi);
+ if (opt.timeout != napi.busy_poll_to ||
+ opt.prefer_busy_poll != napi.prefer_busy_poll) {
+ fprintf(stderr, "Expected busy poll to = %d, got %d\n",
+ opt.timeout, napi.busy_poll_to);
+ fprintf(stderr, "Expected prefer busy poll = %d, got %d\n",
+ opt.prefer_busy_poll, napi.prefer_busy_poll);
+ }
+ } else {
+ io_uring_unregister_napi(&ctx.ring, NULL);
+ }
+ io_uring_queue_exit(&ctx.ring);
+
+ free(ctx.rtt);
+ close(ctx.sockfd);
+
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,386 @@
+#include <ctype.h>
+#include <errno.h>
+#include <getopt.h>
+#include <liburing.h>
+#include <math.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <time.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+
+#define MAXBUFLEN 100
+#define PORTNOLEN 10
+#define ADDRLEN 80
+#define RINGSIZE 1024
+
+#define printable(ch) (isprint((unsigned char)ch) ? ch : '#')
+
+enum {
+ IOURING_RECV,
+ IOURING_SEND,
+ IOURING_RECVMSG,
+ IOURING_SENDMSG
+};
+
+struct ctx
+{
+ struct io_uring ring;
+ struct sockaddr_in6 saddr;
+ struct iovec iov;
+ struct msghdr msg;
+
+ int sockfd;
+ int buffer_len;
+ int num_pings;
+ bool napi_check;
+
+ union {
+ char buffer[MAXBUFLEN];
+ struct timespec ts;
+ };
+} ctx;
+
+struct options
+{
+ int num_pings;
+ int timeout;
+
+ bool listen;
+ bool sq_poll;
+ bool busy_loop;
+ bool prefer_busy_poll;
+
+ char port[PORTNOLEN];
+ char addr[ADDRLEN];
+} options;
+
+struct option longopts[] =
+{
+ {"address" , 1, NULL, 'a'},
+ {"busy" , 0, NULL, 'b'},
+ {"help" , 0, NULL, 'h'},
+ {"listen" , 0, NULL, 'l'},
+ {"num_pings", 1, NULL, 'n'},
+ {"port" , 1, NULL, 'p'},
+ {"prefer" , 1, NULL, 'u'},
+ {"sqpoll" , 0, NULL, 's'},
+ {"timeout" , 1, NULL, 't'},
+ {NULL , 0, NULL, 0 }
+};
+
+static void printUsage(const char *name)
+{
+ fprintf(stderr,
+ "Usage: %s [-l|--listen] [-a|--address ip_address] [-p|--port port-no] [-s|--sqpoll]"
+ " [-b|--busy] [-n|--num pings] [-t|--timeout busy-poll-timeout] [-u|--prefer] [-h|--help]\n"
+ " --listen\n"
+ "-l : Server mode\n"
+ "--address\n"
+ "-a : remote or local ipv6 address\n"
+ "--busy\n"
+ "-b : busy poll io_uring instead of blocking.\n"
+ "--num_pings\n"
+ "-n : number of pings\n"
+ "--port\n"
+ "-p : port\n"
+ "--sqpoll\n"
+ "-s : Configure io_uring to use SQPOLL thread\n"
+ "--timeout\n"
+ "-t : Configure NAPI busy poll timeoutn"
+ "--prefer\n"
+ "-u : prefer NAPI busy poll\n"
+ "--help\n"
+ "-h : Display this usage message\n\n",
+ name);
+}
+
+static void printError(const char *msg, int opt)
+{
+ if (msg && opt)
+ fprintf(stderr, "%s (-%c)\n", msg, printable(opt));
+}
+
+static void setProcessScheduler()
+{
+ struct sched_param param;
+
+ param.sched_priority = sched_get_priority_max(SCHED_FIFO);
+ if (sched_setscheduler(0, SCHED_FIFO, ¶m) < 0)
+ fprintf(stderr, "sched_setscheduler() failed: (%d) %s\n",
+ errno, strerror(errno));
+}
+
+static uint64_t encodeUserData(char type, int fd)
+{
+ return (uint32_t)fd | ((__u64)type << 56);
+}
+
+static void decodeUserData(uint64_t data, char *type, int *fd)
+{
+ *type = data >> 56;
+ *fd = data & 0xffffffffU;
+}
+
+static const char *opTypeToStr(char type)
+{
+ const char *res;
+
+ switch (type) {
+ case IOURING_RECV:
+ res = "IOURING_RECV";
+ break;
+ case IOURING_SEND:
+ res = "IOURING_SEND";
+ break;
+ case IOURING_RECVMSG:
+ res = "IOURING_RECVMSG";
+ break;
+ case IOURING_SENDMSG:
+ res = "IOURING_SENDMSG";
+ break;
+ default:
+ res = "Unknown";
+ }
+
+ return res;
+}
+
+static void reportNapi(struct ctx *ctx)
+{
+ unsigned int napi_id = 0;
+ socklen_t len = sizeof(napi_id);
+
+ getsockopt(ctx->sockfd, SOL_SOCKET, SO_INCOMING_NAPI_ID, &napi_id, &len);
+ if (napi_id)
+ printf(" napi id: %d\n", napi_id);
+ else
+ printf(" unassigned napi id\n");
+
+ ctx->napi_check = true;
+}
+
+static void sendPing(struct ctx *ctx)
+{
+
+ struct io_uring_sqe *sqe = io_uring_get_sqe(&ctx->ring);
+
+ io_uring_prep_sendmsg(sqe, ctx->sockfd, &ctx->msg, 0);
+ sqe->user_data = encodeUserData(IOURING_SENDMSG, ctx->sockfd);
+}
+
+static void receivePing(struct ctx *ctx)
+{
+ bzero(&ctx->msg, sizeof(struct msghdr));
+ ctx->msg.msg_name = &ctx->saddr;
+ ctx->msg.msg_namelen = sizeof(struct sockaddr_in6);
+ ctx->iov.iov_base = ctx->buffer;
+ ctx->iov.iov_len = MAXBUFLEN;
+ ctx->msg.msg_iov = &ctx->iov;
+ ctx->msg.msg_iovlen = 1;
+
+ struct io_uring_sqe *sqe = io_uring_get_sqe(&ctx->ring);
+ io_uring_prep_recvmsg(sqe, ctx->sockfd, &ctx->msg, 0);
+ sqe->user_data = encodeUserData(IOURING_RECVMSG, ctx->sockfd);
+}
+
+static void completion(struct ctx *ctx, struct io_uring_cqe *cqe)
+{
+ char type;
+ int fd;
+ int res = cqe->res;
+
+ decodeUserData(cqe->user_data, &type, &fd);
+ if (res < 0) {
+ fprintf(stderr, "unexpected %s failure: (%d) %s\n",
+ opTypeToStr(type), -res, strerror(-res));
+ abort();
+ }
+
+ switch (type) {
+ case IOURING_SENDMSG:
+ receivePing(ctx);
+ --ctx->num_pings;
+ break;
+ case IOURING_RECVMSG:
+ ctx->iov.iov_len = res;
+ sendPing(ctx);
+ if (!ctx->napi_check)
+ reportNapi(ctx);
+ break;
+ default:
+ fprintf(stderr, "unexpected %s completion\n",
+ opTypeToStr(type));
+ abort();
+ break;
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ int flag;
+ struct ctx ctx;
+ struct options opt;
+ struct __kernel_timespec *tsPtr;
+ struct __kernel_timespec ts;
+ struct io_uring_params params;
+ struct io_uring_napi napi;
+
+ memset(&opt, 0, sizeof(struct options));
+
+ // Process flags.
+ while ((flag = getopt_long(argc, argv, ":lhsbua:n:p:t:", longopts, NULL)) != -1) {
+ switch (flag) {
+ case 'a':
+ strcpy(opt.addr, optarg);
+ break;
+ case 'b':
+ opt.busy_loop = true;
+ break;
+ case 'h':
+ printUsage(argv[0]);
+ exit(0);
+ break;
+ case 'l':
+ opt.listen = true;
+ break;
+ case 'n':
+ opt.num_pings = atoi(optarg) + 1;
+ break;
+ case 'p':
+ strcpy(opt.port, optarg);
+ break;
+ case 's':
+ opt.sq_poll = true;
+ break;
+ case 't':
+ opt.timeout = atoi(optarg);
+ break;
+ case 'u':
+ opt.prefer_busy_poll = true;
+ break;
+ case ':':
+ printError("Missing argument", optopt);
+ printUsage(argv[0]);
+ exit(-1);
+ break;
+ case '?':
+ printError("Unrecognized option", optopt);
+ printUsage(argv[0]);
+ exit(-1);
+ break;
+
+ default:
+ fprintf(stderr, "Fatal: Unexpected case in CmdLineProcessor switch()\n");
+ exit(-1);
+ break;
+ }
+ }
+
+ if (strlen(opt.addr) == 0) {
+ fprintf(stderr, "address option is mandatory\n");
+ printUsage(argv[0]);
+ exit(1);
+ }
+
+ ctx.saddr.sin6_port = htons(atoi(opt.port));
+ ctx.saddr.sin6_family = AF_INET6;
+
+ if (inet_pton(AF_INET6, opt.addr, &ctx.saddr.sin6_addr) <= 0) {
+ fprintf(stderr, "inet_pton error for %s\n", optarg);
+ printUsage(argv[0]);
+ exit(1);
+ }
+
+ // Connect to server.
+ fprintf(stdout, "Listening %s : %s...\n", opt.addr, opt.port);
+
+ if ((ctx.sockfd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+ fprintf(stderr, "socket() failed: (%d) %s\n", errno, strerror(errno));
+ exit(1);
+ }
+
+ if (bind(ctx.sockfd, (struct sockaddr *)&ctx.saddr, sizeof(struct sockaddr_in6)) < 0) {
+ fprintf(stderr, "bind() failed: (%d) %s\n", errno, strerror(errno));
+ exit(1);
+ }
+
+ // Setup ring.
+ memset(¶ms, 0, sizeof(params));
+ memset(&ts, 0, sizeof(ts));
+ memset(&napi, 0, sizeof(napi));
+
+ if (opt.sq_poll) {
+ params.flags = IORING_SETUP_SQPOLL;
+ params.sq_thread_idle = 50;
+ }
+
+ if (io_uring_queue_init_params(RINGSIZE, &ctx.ring, ¶ms) < 0) {
+ fprintf(stderr, "io_uring_queue_init_params() failed: (%d) %s\n",
+ errno, strerror(errno));
+ exit(1);
+ }
+
+ if (opt.timeout || opt.prefer_busy_poll) {
+ napi.prefer_busy_poll = opt.prefer_busy_poll;
+ napi.busy_poll_to = opt.timeout;
+
+ io_uring_register_napi(&ctx.ring, &napi);
+ }
+
+ if (opt.busy_loop)
+ tsPtr = &ts;
+ else
+ tsPtr = NULL;
+
+
+ // Use realtime scheduler.
+ setProcessScheduler();
+
+ // Copy payload.
+ clock_gettime(CLOCK_REALTIME, &ctx.ts);
+
+ // Setup context.
+ ctx.napi_check = false;
+ ctx.buffer_len = sizeof(struct timespec);
+ ctx.num_pings = opt.num_pings;
+
+ // Receive initial message to get napi id.
+ receivePing(&ctx);
+
+ while (ctx.num_pings != 0) {
+ int res;
+ unsigned int num_completed = 0;
+ unsigned int head;
+ struct io_uring_cqe *cqe;
+
+ do {
+ res = io_uring_submit_and_wait_timeout(&ctx.ring, &cqe, 1, tsPtr, NULL);
+ }
+ while (res < 0 && errno == ETIME);
+
+ io_uring_for_each_cqe(&ctx.ring, head, cqe) {
+ ++num_completed;
+ completion(&ctx, cqe);
+ }
+
+ if (num_completed) {
+ io_uring_cq_advance(&ctx.ring, num_completed);
+ }
+ }
+
+ // Clean up.
+ if (opt.timeout || opt.prefer_busy_poll)
+ io_uring_unregister_napi(&ctx.ring, &napi);
+
+ io_uring_queue_exit(&ctx.ring);
+ close(ctx.sockfd);
+
+ return 0;
+}
This adds two example programs to test the napi busy poll functionality. It consists of a client program and a server program. To get a napi id, the client and the server program need to be run on different hosts. To test the napi busy poll timeout, the -t needs to be specified. A reasonable value for the busy poll timeout is 100. By specifying the busy poll timeout on the server and the client the best results are accomplished. Signed-off-by: Stefan Roesch <shr@devkernel.io> --- .gitignore | 2 + examples/Makefile | 2 + examples/napi-busy-poll-client.c | 451 +++++++++++++++++++++++++++++++ examples/napi-busy-poll-server.c | 386 ++++++++++++++++++++++++++ 4 files changed, 841 insertions(+) create mode 100644 examples/napi-busy-poll-client.c create mode 100644 examples/napi-busy-poll-server.c