From 470d72f54abbd3e34053cc4f4e281593faf0fb77 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Thu, 1 Jun 2023 21:50:03 -0700 Subject: vcl: fix epoll ctl frequent deq ntf requests SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL should be treated as a config option that is not frequently changed. Or alternatively, it should be set together with SVM_FIFO_WANT_DEQ_NOTIF to elicit a one time tx notification. Type: fix Signed-off-by: Florin Coras Change-Id: Ie4132c7789ee87227a875ff981eb98f9f4d898a9 --- src/vcl/vppcom.c | 48 ++++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) (limited to 'src/vcl') diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c index 474670e7565..f2166f851ae 100644 --- a/src/vcl/vppcom.c +++ b/src/vcl/vppcom.c @@ -2868,15 +2868,22 @@ vppcom_epoll_ctl (uint32_t vep_handle, int op, uint32_t session_handle, s->flags |= VCL_SESSION_F_IS_VEP_SESSION; vep_session->vep.next_sh = session_handle; - if (event->events & EPOLLOUT) - vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); - - /* Generate EPOLLOUT if tx fifo not full */ - if ((event->events & EPOLLOUT) && (vcl_session_write_ready (s) > 0)) + if ((event->events & EPOLLOUT)) { - vcl_epoll_ctl_add_unhandled_event (wrk, s, event->events & EPOLLET, - SESSION_IO_EVT_TX); - add_evt = 1; + int write_ready = vcl_session_write_ready (s); + + vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); + if (write_ready > 0) + { + /* Generate EPOLLOUT if tx fifo not full */ + vcl_epoll_ctl_add_unhandled_event ( + wrk, s, event->events & EPOLLET, SESSION_IO_EVT_TX); + add_evt = 1; + } + else + { + vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF); + } } /* Generate EPOLLIN if rx fifo has data */ if ((event->events & EPOLLIN) && (vcl_session_read_ready (s) > 0)) @@ -2922,18 +2929,23 @@ vppcom_epoll_ctl (uint32_t vep_handle, int op, uint32_t session_handle, goto done; } - if (event->events & EPOLLOUT) - vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); - else - vcl_session_del_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); - - /* Generate EPOLLOUT if session write ready nd event was not on */ - if ((event->events & EPOLLOUT) && !(s->vep.ev.events & EPOLLOUT) && - (vcl_session_write_ready (s) > 0)) + /* Generate EPOLLOUT if session write ready and event was not on */ + if ((event->events & EPOLLOUT) && !(s->vep.ev.events & EPOLLOUT)) { - vcl_epoll_ctl_add_unhandled_event (wrk, s, event->events & EPOLLET, - SESSION_IO_EVT_TX); + /* Fifo size load acq synchronized with update store rel */ + int write_ready = vcl_session_write_ready (s); + + vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); + if (write_ready > 0) + vcl_epoll_ctl_add_unhandled_event (wrk, s, event->events & EPOLLET, + SESSION_IO_EVT_TX); + else + /* Request deq ntf in case dequeue happened while updating flag */ + vcl_session_add_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF); } + else if (!(event->events & EPOLLOUT)) + vcl_session_del_want_deq_ntf (s, SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL); + /* Generate EPOLLIN if session read ready and event was not on */ if ((event->events & EPOLLIN) && !(s->vep.ev.events & EPOLLIN) && (vcl_session_read_ready (s) > 0)) -- cgit 1.2.3-korg