lkml.org 
[lkml]   [2003]   [Oct]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: question on incoming packets and scheduler
Davide Libenzi wrote:
> On Wed, 15 Oct 2003, Chris Friesen wrote:

>>It appears that 2.4.20 fixes this issue, but there is another one
>>remaining that the latency appears to be dependent on the number of
>>incoming packets. See thread "incoming packet latency in 2.4.[18-20]"
>>for details. This behaviour doesn't show up in 2.6, and I'm about to
>>test 2.4.22.

> Are you sure it's not a livelock issue during the burst?

I dunno, you tell me.

The test app simply sits in select() until a packet comes in, then it
spins on recvmsg() until there are no more messages. It uses
SO_TIMESTAMP to find out when the packet got to the kernel, and does a
gettimeofday() right after the recvmsg(), then calculates the delta for
each packet and the overall average.

With 2.4.[18-20], the overall average goes up when the number of packets
goes up. For 2.6.0-test6, it stays constant.

Chris




--
Chris Friesen | MailStop: 043/33/F10
Nortel Networks | work: (613) 765-0557
3500 Carling Avenue | fax: (613) 765-2986
Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com

-
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 13:49    [W:0.031 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site