The poll call can return POLLERR which is ignored, or it can return
POLLOUT, even if there are no free frames in the mmap-ed area.
We can account for both of these cases by re-checking if the next
frame is empty before writing into it.
We have attempted to reproduce this issue with pktgen-dpdk, using the
following configuration.
pktgen -l 1-4 -n 4 --proc-type=primary --no-pci --no-telemetry \
--no-huge -m 512 \
--vdev=net_af_packet0,iface=eth1,blocksz=16384,framesz=8192, \
framecnt=2048,qpairs=1,qdisc_bypass=0 \
-- \
-P \
-T \
-m "3.0" \
-f themes/black-yellow.theme
We configure a low tx rate (~ 335 packets / second) and a small
packet size, of about 300 Bytes from the pktgen CLI.
set 0 size 300
set 0 rate 0.008
set 0 burst 1
start 0
After bringing the interface down, and up again, we seem to arrive
in a state in which the tx rate is inconsistent, and does not recover.
ifconfig eth1 down; sleep 7; ifconfig eth1 up
[1] http://code.dpdk.org/pktgen-dpdk/pktgen-20.11.2/source/INSTALL.md
Fixes: 364e08f2bb ("af_packet: add PMD for AF_PACKET-based virtual devices")
Cc: stable@dpdk.org
Signed-off-by: Mihai Pogonaru <pogonarumihai@gmail.com>
Signed-off-by: Tudor Cornea <tudor.cornea@gmail.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
f86d553cc1