Re: ipgre rss is broken since gro

On Sun, Dec 9, 2012 at 12:49 PM, Dmitry Kravkov [off-list ref] wrote:

for this item: drop_watch does not show any drops (i've disable all
other interfaces for clear env)
I will explain a little bit more the setup:
bnx2x device (under testing) is configured for RSS for IPGRE packets.
Sending multiple (3) TCP_STREAM causes ip_gre interface to disappear
packets (even ICMP).
This is not happening with single TCP_STREAM, or before gro_cell
introduction.

i was searching for the drops by print-out in ip_gre.c but disappeared
packets completes this code:

static int ipgre_rcv(struct sk_buff *skb)
(snip)
                printk("%s:%d\n", __FUNCTION__, __LINE__);

                tstats = this_cpu_ptr(tunnel->dev->tstats);
                u64_stats_update_begin(&tstats->syncp);
                tstats->rx_packets++;
                tstats->rx_bytes += skb->len;
                u64_stats_update_end(&tstats->syncp);

                gro_cells_receive(&tunnel->gro_cells, skb);
                return 0;

I dont know, I tried a bnx2x setup, and 100 tcp flows, no special problem.

If you receive a lot of packets on a single RX queue, they might be
dropped because cpu cant cope with the load
(This has nothing to do with GRE or GRO )

cat /proc/net/softnet_stat