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authorFlorin Coras <fcoras@cisco.com>2023-06-01 21:50:03 -0700
committerAndrew Yourtchenko <ayourtch@gmail.com>2023-06-13 12:50:09 +0000
commitfcbf306cf3c8e530117e6f77fd477afb21b62e51 (patch)
tree40f5e51b88b61d0aaf1d3b4b4f43576eafe1034c
parent16912d23abaa652ac6fe00b1af9b4f09c728b3b1 (diff)
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 <fcoras@cisco.com> Change-Id: Ie4132c7789ee87227a875ff981eb98f9f4d898a9 (cherry picked from commit 470d72f54abbd3e34053cc4f4e281593faf0fb77)
-rw-r--r--src/vcl/vppcom.c48
1 files changed, 30 insertions, 18 deletions
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))