[RFC PATCH v2 0/2] nb8800 suspend/resume support
From: Måns Rullgård <hidden>
Date: 2017-08-02 16:43:05
Also in:
netdev
Mason [off-list ref] writes:
quoted hunk
On 02/08/2017 18:10, M?ns Rullg?rd wrote:quoted
Mason writes:quoted
On 02/08/2017 17:56, M?ns Rullg?rd wrote:quoted
What does the tango5 do if you flood it with packets faster than the kernel can keep up with? That would make it hit the end of the rx chain, which is apparently what makes it miserable with the current dma stop code.The simplest way to test this would be sending tiny packets as fast as possible, right? So ping -f on a GigE link should fit the bill?ping -f is limited to 100 packets per second. Use something like iperf in UDP mode instead.ping -f can go 100 times faster than 100 pps: # ping -f -q -c 150000 -s 300 172.27.64.45 PING 172.27.64.45 (172.27.64.45) 300(328) bytes of data.--- 172.27.64.45 ping statistics ---150000 packets transmitted, 150000 received, 0% packet loss, time 15035ms rtt min/avg/max/mdev = 0.065/0.084/0.537/0.014 ms, ipg/ewma 0.100/0.087 ms 150,000 packets in 15 seconds = 10,000 pps (172.27.64.45 is the tango5 board) Ergo, dealing with 10,000 packets per second does not hose RX.
ping -f goes as fast as the other end replies or 100 per second, whichever is higher, so says the man page. -- M?ns Rullg?rd