On Mon, Jan 18, 2010 at 11:29:31AM -0500, Michael Breuer wrote:Yes - dk if it's significant or not. Only obvious difference between DMAR and not.
Ok - up on the two patches, no DMAR. Some early observations:OK, you mentioned this oops (actually a warning only) happened during
1. There's an early on MMAP oops (see below). This happens once, at
the completion of the transition to runlevel 5 (I've seen it
entering runlevel 3 as well). This does not recur when runlevels are
subsequently changed. I do not see this when running with DMAR
previous tests too.
I had been focusing on the hangs - dhcp causing the initial crash from December. After things stabilized with the af patch & skb may pull I started noticing the dropped tx packets. I reported the TX loss on the 16th of January after confirming the issue.2. The dropped tx packet (DHCP) is a bit harder to recreate, but itBtw, I guess you improved the test because you didn't mention it here,
even after my explicit question?:
Yes. There are no errors, and no statistics anywhere that I know to look reflect the loss. Nothing in netstat; ethtool -S; etc. The only loss reported is RX. The recent TX warnings/resets happened while the machine was up for several days and while unattended and under high RX load.Interestingly, I initially saw no dropped packetsI forgot to mention, but did you try to check if these lost ping
with ping - but after I went the DCHP route and eventually
reconnected, I could then cause dropped tx packets with ping. To
a) start throughput
b) ping device - no packet loss - this was true for the entire test run.
c) start throughput again
d) ping - no loss.
e) drop wifi on the device& restart - first attempt worked. Repeat
attempt yielded the dropped DHCPOFFER packets. After about 6 tries,
the device reconnected to wifi.
f) ping again (after the reconnection) - packet loss rate about 80%.
g) simultaneously ping the wifi router - no loss.
h) After a while, packets are no longer dropped during ping. If I
manage to cause the dhcp drop again, and then ping after the device
finally reconnects, packet loss is significant for a while (maybe 30
sec to a minute). Then things return to normal. Note that the packet
loss continues even if the reported throughput drops to nil.
i) I can't cause the initial packet loss at RX rates below about
30,000KBPS (as reported by nethogs). At rates over 40 I can
reproduce this on this set of patches& config about 60% of the
packets are "being dropped somewhere after wireshark sees them and
before hitting the wire" like DHCPOFFER? Aren't there any sky2
warnings/resets while this happens?