From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7655FC636CC for ; Sun, 5 Feb 2023 18:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229463AbjBESvp (ORCPT ); Sun, 5 Feb 2023 13:51:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjBESvo (ORCPT ); Sun, 5 Feb 2023 13:51:44 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6224193CF for ; Sun, 5 Feb 2023 10:51:41 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 5FB9B658CF48; Sun, 5 Feb 2023 10:51:28 -0800 (PST) From: Stefan Roesch To: io-uring@vger.kernel.org, kernel-team@fb.com Cc: shr@devkernel.io, axboe@kernel.dk, ammarfaizi2@gnuweeb.org Subject: [PATCH v8 3/4] liburing: add example programs for napi busy poll Date: Sun, 5 Feb 2023 10:51:21 -0800 Message-Id: <20230205185122.2096480-4-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230205185122.2096480-1-shr@devkernel.io> References: <20230205185122.2096480-1-shr@devkernel.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 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 Acked-by: Ammar Faizi --- .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 diff --git a/.gitignore b/.gitignore index 0cd84dc..edccea9 100644 --- a/.gitignore +++ b/.gitignore @@ -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 diff --git a/examples/Makefile b/examples/Makefile index e561e05..59f1260 100644 --- a/examples/Makefile +++ b/examples/Makefile @@ -15,6 +15,8 @@ example_srcs :=3D \ 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 =20 diff --git a/examples/napi-busy-poll-client.c b/examples/napi-busy-poll-c= lient.c new file mode 100644 index 0000000..37adaee --- /dev/null +++ b/examples/napi-busy-poll-client.c @@ -0,0 +1,451 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; +}; + +struct options +{ + int num_pings; + __u32 timeout; + + bool sq_poll; + bool busy_loop; + bool prefer_busy_poll; + + char port[PORTNOLEN]; + char addr[ADDRLEN]; +}; + +static struct option longopts[] =3D +{ + {"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 =3D 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 ti= mespec *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 =3D data >> 56; + *fd =3D data & 0xffffffffU; +} + +static const char *opTypeToStr(char type) +{ + const char *res; + + switch (type) { + case IOURING_RECV: + res =3D "IOURING_RECV"; + break; + case IOURING_SEND: + res =3D "IOURING_SEND"; + break; + case IOURING_RECVMSG: + res =3D "IOURING_RECVMSG"; + break; + case IOURING_SENDMSG: + res =3D "IOURING_SENDMSG"; + break; + default: + res =3D "Unknown"; + } + + return res; +} + +static void reportNapi(struct ctx *ctx) +{ + unsigned int napi_id =3D 0; + socklen_t len =3D 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 =3D true; +} + +static void sendPing(struct ctx *ctx) +{ + struct io_uring_sqe *sqe =3D 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 timespe= c), 0); + sqe->user_data =3D encodeUserData(IOURING_SEND, ctx->sockfd); +} + +static void receivePing(struct ctx *ctx) +{ + struct io_uring_sqe *sqe =3D io_uring_get_sqe(&ctx->ring); + + io_uring_prep_recv(sqe, ctx->sockfd, ctx->buffer, MAXBUFLEN, 0); + sqe->user_data =3D encodeUserData(IOURING_RECV, ctx->sockfd); +} + +static void recordRTT(struct ctx *ctx) +{ + struct timespec startTs =3D ctx->ts; + + // Send next ping. + sendPing(ctx); + + // Store round-trip time. + ctx->rtt[ctx->rtt_index] =3D diffTimespec(&ctx->ts, &startTs); + ctx->rtt_index++; +} + +static void printStats(struct ctx *ctx) +{ + double minRTT =3D DBL_MAX; + double maxRTT =3D 0.0; + double avgRTT =3D 0.0; + double stddevRTT =3D 0.0; + + // Calculate min, max, avg. + for (int i =3D 0; i < ctx->rtt_index; i++) { + if (ctx->rtt[i] < minRTT) + minRTT =3D ctx->rtt[i]; + if (ctx->rtt[i] > maxRTT) + maxRTT =3D ctx->rtt[i]; + + avgRTT +=3D ctx->rtt[i]; + } + avgRTT /=3D ctx->rtt_index; + + // Calculate stddev. + for (int i =3D 0; i < ctx->rtt_index; i++) + stddevRTT +=3D fabs(ctx->rtt[i] - avgRTT); + stddevRTT /=3D ctx->rtt_index; + + fprintf(stdout, " rtt(us) min/avg/max/mdev =3D %.3f/%.3f/%.3f/%.3f\n", + minRTT * 1000000, avgRTT * 1000000, maxRTT * 1000000, stddevRTT * 1000= 000); +} + +static int completion(struct ctx *ctx, struct io_uring_cqe *cqe) +{ + char type; + int fd; + int res =3D 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 !=3D 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 =3D getopt_long(argc, argv, ":hsbua:n:p:t:", longopts, NUL= L)) !=3D -1) { + switch (flag) { + case 'a': + strcpy(opt.addr, optarg); + break; + case 'b': + opt.busy_loop =3D true; + break; + case 'h': + printUsage(argv[0]); + exit(0); + break; + case 'n': + opt.num_pings =3D atoi(optarg) + 1; + break; + case 'p': + strcpy(opt.port, optarg); + break; + case 's': + opt.sq_poll =3D true; + break; + case 't': + opt.timeout =3D atoi(optarg); + break; + case 'u': + opt.prefer_busy_poll =3D 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) =3D=3D 0) { + fprintf(stderr, "address option is mandatory\n"); + printUsage(argv[0]); + exit(1); + } + + ctx.saddr.sin6_port =3D htons(atoi(opt.port)); + ctx.saddr.sin6_family =3D AF_INET6; + + if (inet_pton(AF_INET6, opt.addr, &ctx.saddr.sin6_addr) <=3D 0) { + fprintf(stderr, "inet_pton error for %s\n", optarg); + printUsage(argv[0]); + exit(1); + } + + // Connect to server. + fprintf(stdout, "Connecting to %s... (port=3D%s) to send %d pings\n", o= pt.addr, opt.port, opt.num_pings - 1); + + if ((ctx.sockfd =3D 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 so= ckaddr_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 =3D IORING_SETUP_SQPOLL; + params.sq_thread_idle =3D 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 =3D opt.prefer_busy_poll; + napi.busy_poll_to =3D opt.timeout; + + io_uring_register_napi(&ctx.ring, &napi); + } + + if (opt.busy_loop) + tsPtr =3D &ts; + else + tsPtr =3D NULL; + + // Use realtime scheduler. + setProcessScheduler(); + + // Copy payload. + clock_gettime(CLOCK_REALTIME, &ctx.ts); + + // Setup context. + ctx.napi_check =3D false; + ctx.buffer_len =3D sizeof(struct timespec); + ctx.num_pings =3D opt.num_pings; + + ctx.rtt_index =3D 0; + ctx.rtt =3D (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 !=3D 0) { + int res; + unsigned num_completed =3D 0; + unsigned head; + struct io_uring_cqe *cqe; + + do { + res =3D io_uring_submit_and_wait_timeout(&ctx.ring, &cqe, 1, tsPtr, N= ULL); + } + while (res < 0 && errno =3D=3D 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 !=3D napi.busy_poll_to || + opt.prefer_busy_poll !=3D napi.prefer_busy_poll) { + fprintf(stderr, "Expected busy poll to =3D %d, got %d\n", + opt.timeout, napi.busy_poll_to); + fprintf(stderr, "Expected prefer busy poll =3D %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; +} diff --git a/examples/napi-busy-poll-server.c b/examples/napi-busy-poll-s= erver.c new file mode 100644 index 0000000..ccfd91f --- /dev/null +++ b/examples/napi-busy-poll-server.c @@ -0,0 +1,386 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; + }; +}; + +struct options +{ + int num_pings; + __u32 timeout; + + bool listen; + bool sq_poll; + bool busy_loop; + bool prefer_busy_poll; + + char port[PORTNOLEN]; + char addr[ADDRLEN]; +}; + +static struct option longopts[] =3D +{ + {"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|--p= refer] [-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(void) +{ + struct sched_param param; + + param.sched_priority =3D 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 =3D data >> 56; + *fd =3D data & 0xffffffffU; +} + +static const char *opTypeToStr(char type) +{ + const char *res; + + switch (type) { + case IOURING_RECV: + res =3D "IOURING_RECV"; + break; + case IOURING_SEND: + res =3D "IOURING_SEND"; + break; + case IOURING_RECVMSG: + res =3D "IOURING_RECVMSG"; + break; + case IOURING_SENDMSG: + res =3D "IOURING_SENDMSG"; + break; + default: + res =3D "Unknown"; + } + + return res; +} + +static void reportNapi(struct ctx *ctx) +{ + unsigned int napi_id =3D 0; + socklen_t len =3D 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 =3D true; +} + +static void sendPing(struct ctx *ctx) +{ + + struct io_uring_sqe *sqe =3D io_uring_get_sqe(&ctx->ring); + + io_uring_prep_sendmsg(sqe, ctx->sockfd, &ctx->msg, 0); + sqe->user_data =3D encodeUserData(IOURING_SENDMSG, ctx->sockfd); +} + +static void receivePing(struct ctx *ctx) +{ + bzero(&ctx->msg, sizeof(struct msghdr)); + ctx->msg.msg_name =3D &ctx->saddr; + ctx->msg.msg_namelen =3D sizeof(struct sockaddr_in6); + ctx->iov.iov_base =3D ctx->buffer; + ctx->iov.iov_len =3D MAXBUFLEN; + ctx->msg.msg_iov =3D &ctx->iov; + ctx->msg.msg_iovlen =3D 1; + + struct io_uring_sqe *sqe =3D io_uring_get_sqe(&ctx->ring); + io_uring_prep_recvmsg(sqe, ctx->sockfd, &ctx->msg, 0); + sqe->user_data =3D encodeUserData(IOURING_RECVMSG, ctx->sockfd); +} + +static void completion(struct ctx *ctx, struct io_uring_cqe *cqe) +{ + char type; + int fd; + int res =3D 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 =3D 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 =3D getopt_long(argc, argv, ":lhsbua:n:p:t:", longopts, NU= LL)) !=3D -1) { + switch (flag) { + case 'a': + strcpy(opt.addr, optarg); + break; + case 'b': + opt.busy_loop =3D true; + break; + case 'h': + printUsage(argv[0]); + exit(0); + break; + case 'l': + opt.listen =3D true; + break; + case 'n': + opt.num_pings =3D atoi(optarg) + 1; + break; + case 'p': + strcpy(opt.port, optarg); + break; + case 's': + opt.sq_poll =3D true; + break; + case 't': + opt.timeout =3D atoi(optarg); + break; + case 'u': + opt.prefer_busy_poll =3D 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) =3D=3D 0) { + fprintf(stderr, "address option is mandatory\n"); + printUsage(argv[0]); + exit(1); + } + + ctx.saddr.sin6_port =3D htons(atoi(opt.port)); + ctx.saddr.sin6_family =3D AF_INET6; + + if (inet_pton(AF_INET6, opt.addr, &ctx.saddr.sin6_addr) <=3D 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 =3D 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 socka= ddr_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 =3D IORING_SETUP_SQPOLL; + params.sq_thread_idle =3D 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 =3D opt.prefer_busy_poll; + napi.busy_poll_to =3D opt.timeout; + + io_uring_register_napi(&ctx.ring, &napi); + } + + if (opt.busy_loop) + tsPtr =3D &ts; + else + tsPtr =3D NULL; + + + // Use realtime scheduler. + setProcessScheduler(); + + // Copy payload. + clock_gettime(CLOCK_REALTIME, &ctx.ts); + + // Setup context. + ctx.napi_check =3D false; + ctx.buffer_len =3D sizeof(struct timespec); + ctx.num_pings =3D opt.num_pings; + + // Receive initial message to get napi id. + receivePing(&ctx); + + while (ctx.num_pings !=3D 0) { + int res; + unsigned int num_completed =3D 0; + unsigned int head; + struct io_uring_cqe *cqe; + + do { + res =3D io_uring_submit_and_wait_timeout(&ctx.ring, &cqe, 1, tsPtr, N= ULL); + } + while (res < 0 && errno =3D=3D 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; +} --=20 2.30.2