Red Hat Bugzilla – Bug 80709
HTB packet scheduler works incorectly with HZ other than 100 or 1024
Last modified: 2007-04-18 12:49:22 EDT
Description of problem:
HTB packet scheduler works not correctly when HZ is other than 100
or 1024. RedHat's default is 512. And problem appears only with
UDP traffic. TCP is shaped OK.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Setup traffic shaping with HTB class.
2. Flood link with UDP traffic.
Traffic exceeds set limit or even is not shaped at all.
At least in include/net/pkt_sched.h there is the following code:
#if HZ == 100
#define PSCHED_JSCALE 13
#elif HZ == 1024
#define PSCHED_JSCALE 10
#define PSCHED_JSCALE 0
ought to be fixed in current erratum