lkml.org 
[lkml]   [2006]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRE: ~5x greater CPU load for a networked application when using 2.6.15-rt15-smp vs. 2.6.12-1.1390_FC4
As a follow up to previous emails (Gautam Thaker, Ingo Molnar, Ted Tso, et. al.) on the subject of large CPU overhead by the RT kernel when under heavy network load, I ran the following test in order to get more reasonable data.  I have 19 nodes with 20 "virtual" node processes sending UDP messages to a single host at a rate of 100Hz for 38,000 packets per second.  Using cyclesoak to determine cpu usage (over 240 samples, 1 sample per second), I found the following results:

RT kernel: linux-2.6.17-rt1-uni
Mean: 48.9%
Variance: 5.91
Standard Deviation: 2.43

Standard kernel: Standard Fedora Core 4
Mean: 23.2%
Variance: 0.237
Standard Deviation: 0.4867

Thus I found the average cpu load on the RT kernel to be 2.11 times that of the standard kernel. Hopefully this information will be of some use.

-Jonathan Walsh
Distributed Processing Lab; Lockheed Martin Adv. Tech. Labs

-
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: 2006-07-11 20:11    [W:0.434 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site