![]() | |||||||||||
Messages in this thread |
On Mon, 2004-08-23 at 23:56, K.R. Foley wrote: > Lee Revell wrote: > > On Mon, 2004-08-23 at 17:01, Ingo Molnar wrote: > > > > > >> - reduce netdev_max_backlog to 8 (Mark H Johnson) > >> > > > > > > On my system this setting has absolutely no effect on the skb related > > latencies. I tested setting netdev_max_backlog to every power of two > > between 1 and 128, and regardless of this setting, I can produce a > > 450-600 usec latency with: > > > > ping -s 65507 -f $DEFAULT_GATEWAY > > > > Looks like skb_checksum is the problem. Here is one of the traces: > > > > http://krustophenia.net/testresults.php?dataset=2.6.8.1-P8#/var/www/2.6.8.1-P8/trace14.txt > > > > Lee > > > > - > > Setting netdev_max_backlog doesn't seem to have any effect for me either. > > I get a similar latency when I try to reproduce your result above, ~612 > usec. However, my trace is very different than yours: > > http://www.cybsft.com/testresults/2.6.8.1-P8/latency_trace3.txt > I have some that are similar to this. Looks like many of the differences are due to different network drivers (e100 vs via-rhine). > In fact most any network activity, with the POSSIBLE exception of > already open connections, seem to be able to trigger higher latencies. > As you can see here: > > http://www.cybsft.com/testresults/2.6.8.1-P8/ > Looks like except for the one above, all of these involve the extract_entropy issue. I am using a hack to disable the random driver to avoid these latencies. There are a few other threads going on discussing a real solution to the extract_entropy issue. However, none of the solutions that has been posted yet fix the problem. Lee - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||
| Last update: 2005-03-22 14:05 [from the cache] ©2003-2008 | |||||||||||