Date: Wed, 7 Apr 2021 21:05:35 GMT From: Vincenzo Maffione <vmaffione@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 3f70c3d58f93 - stable/12 - netmap: bridge: fix transmission in busy-wait mode Message-ID: <202104072105.137L5ZB0062832@gitrepo.freebsd.org>
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The branch stable/12 has been updated by vmaffione: URL: https://cgit.FreeBSD.org/src/commit/?id=3f70c3d58f9330039707037b1242ca13ac390cad commit 3f70c3d58f9330039707037b1242ca13ac390cad Author: Vincenzo Maffione <vmaffione@FreeBSD.org> AuthorDate: 2021-03-30 06:24:56 +0000 Commit: Vincenzo Maffione <vmaffione@FreeBSD.org> CommitDate: 2021-04-07 21:05:28 +0000 netmap: bridge: fix transmission in busy-wait mode In busy-wait mode (BUSYWAIT defined), NIOCTXSYNC should be performed after packets have been moved to the TX ring (rather than before). Before the change, moved packets may stall for an indefinite time in the TX ring. MFC after: 1 week (cherry picked from commit 51cc31088bf4d23a6ad0bfe8851adaa049d750fc) --- tools/tools/netmap/bridge.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/tools/tools/netmap/bridge.c b/tools/tools/netmap/bridge.c index 77d235bf6e08..0c8f56265ff4 100644 --- a/tools/tools/netmap/bridge.c +++ b/tools/tools/netmap/bridge.c @@ -17,6 +17,10 @@ #include <stdlib.h> #include <unistd.h> +#if defined(_WIN32) +#define BUSYWAIT +#endif + static int verbose = 0; static int do_abort = 0; @@ -321,21 +325,19 @@ main(int argc, char **argv) pollfd[0].revents = pollfd[1].revents = 0; n0 = rx_slots_avail(pa); n1 = rx_slots_avail(pb); -#if defined(_WIN32) || defined(BUSYWAIT) +#ifdef BUSYWAIT if (n0) { - ioctl(pollfd[1].fd, NIOCTXSYNC, NULL); pollfd[1].revents = POLLOUT; } else { ioctl(pollfd[0].fd, NIOCRXSYNC, NULL); } if (n1) { - ioctl(pollfd[0].fd, NIOCTXSYNC, NULL); pollfd[0].revents = POLLOUT; } else { ioctl(pollfd[1].fd, NIOCRXSYNC, NULL); } ret = 1; -#else +#else /* !defined(BUSYWAIT) */ if (n0) pollfd[1].events |= POLLOUT; else @@ -347,7 +349,7 @@ main(int argc, char **argv) /* poll() also cause kernel to txsync/rxsync the NICs */ ret = poll(pollfd, 2, 2500); -#endif /* defined(_WIN32) || defined(BUSYWAIT) */ +#endif /* !defined(BUSYWAIT) */ if (ret <= 0 || verbose) D("poll %s [0] ev %x %x rx %d@%d tx %d," " [1] ev %x %x rx %d@%d tx %d", @@ -375,11 +377,19 @@ main(int argc, char **argv) D("error on fd1, rx [%d,%d,%d)", rx->head, rx->cur, rx->tail); } - if (pollfd[0].revents & POLLOUT) + if (pollfd[0].revents & POLLOUT) { ports_move(pb, pa, burst, msg_b2a); +#ifdef BUSYWAIT + ioctl(pollfd[0].fd, NIOCTXSYNC, NULL); +#endif + } - if (pollfd[1].revents & POLLOUT) + if (pollfd[1].revents & POLLOUT) { ports_move(pa, pb, burst, msg_a2b); +#ifdef BUSYWAIT + ioctl(pollfd[1].fd, NIOCTXSYNC, NULL); +#endif + } /* * We don't need ioctl(NIOCTXSYNC) on the two file descriptors.
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