Re: [PATCH v3 4/5] testpmd: handle all rxqs in rss setup
From: Nélio Laranjeiro <hidden>
Date: 2016-06-27 14:23:44
On Tue, Jun 14, 2016 at 07:08:05PM -0400, Zhihong Wang wrote:
quoted hunk ↗ jump to hunk
This patch removes constraints in rxq handling when multiqueue is enabled to handle all the rxqs. Current testpmd forces a dedicated core for each rxq, some rxqs may be ignored when core number is less than rxq number, and that causes confusion and inconvenience. One example: One Red Hat engineer was doing multiqueue test, there're 2 ports in guest each with 4 queues, and testpmd was used as the forwarding engine in guest, as usual he used 1 core for forwarding, as a results he only saw traffic from port 0 queue 0 to port 1 queue 0, then a lot of emails and quite some time are spent to root cause it, and of course it's caused by this unreasonable testpmd behavior. Moreover, even if we understand this behavior, if we want to test the above case, we still need 8 cores for a single guest to poll all the rxqs, obviously this is too expensive. We met quite a lot cases like this, one recent example: http://openvswitch.org/pipermail/dev/2016-June/072110.html Signed-off-by: Zhihong Wang <redacted> --- app/test-pmd/config.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c index ede7c78..4719a08 100644 --- a/app/test-pmd/config.c +++ b/app/test-pmd/config.c@@ -1199,19 +1199,13 @@ rss_fwd_config_setup(void) cur_fwd_config.nb_fwd_ports = nb_fwd_ports; cur_fwd_config.nb_fwd_streams = (streamid_t) (nb_q * cur_fwd_config.nb_fwd_ports); - if (cur_fwd_config.nb_fwd_streams > cur_fwd_config.nb_fwd_lcores) - cur_fwd_config.nb_fwd_streams = - (streamid_t)cur_fwd_config.nb_fwd_lcores; - else - cur_fwd_config.nb_fwd_lcores = - (lcoreid_t)cur_fwd_config.nb_fwd_streams; /* reinitialize forwarding streams */ init_fwd_streams(); setup_fwd_config_of_each_lcore(&cur_fwd_config); rxp = 0; rxq = 0; - for (lc_id = 0; lc_id < cur_fwd_config.nb_fwd_lcores; lc_id++) { + for (lc_id = 0; lc_id < cur_fwd_config.nb_fwd_streams; lc_id++) { struct fwd_stream *fs; fs = fwd_streams[lc_id];-- 2.5.0
Hi Zhihong,
It seems this commits introduce a bug in pkt_burst_transmit(), this only
occurs when the number of cores present in the coremask is greater than
the number of queues i.e. coremask=0xffe --txq=4 --rxq=4.
Port 0 Link Up - speed 40000 Mbps - full-duplex
Port 1 Link Up - speed 40000 Mbps - full-duplex
Done
testpmd> start tx_first
io packet forwarding - CRC stripping disabled - packets/burst=64
nb forwarding cores=10 - nb forwarding ports=2
RX queues=4 - RX desc=256 - RX free threshold=0
RX threshold registers: pthresh=0 hthresh=0 wthresh=0
TX queues=4 - TX desc=256 - TX free threshold=0
TX threshold registers: pthresh=0 hthresh=0 wthresh=0
TX RS bit threshold=0 - TXQ flags=0x0
Segmentation fault (core dumped)
If I start testpmd with a coremask with at most as many cores as queues,
everything works well (i.e. coremask=0xff0, or 0xf00).
Are you able to reproduce the same issue?
Note: It only occurs on dpdk/master branch (commit f2bb7ae1d204).
Regards,
--
Nélio Laranjeiro
6WIND