Currently, ovs uses hardcoded rate2quantum = 10 for each htb qdisc. When qdisc class's rate is small, the resulting quantum (calculated by min_rate / rate2quantum) will be smaller than MTU. This is not recommended and tc will keep complaining the following in syslog.
localhost kernel: HTB: quantum of class 10003 is small. Consider r2q change. localhost kernel: HTB: quantum of class 10004 is small. Consider r2q change. localhost kernel: HTB: quantum of class 10005 is small. Consider r2q change. localhost kernel: HTB: quantum of class 10006 is small. Consider r2q change. To fix the issue, this commit makes ovs always use htb quantum no less than the MTU. Signed-off-by: Alex Wang <[email protected]> --- lib/netdev-linux.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c index 5e6f01e..5c0fdff 100644 --- a/lib/netdev-linux.c +++ b/lib/netdev-linux.c @@ -3497,6 +3497,7 @@ static const struct tc_ops tc_ops_sfq = { /* HTB traffic control class. */ #define HTB_N_QUEUES 0xf000 +#define HTB_RATE2QUANTUM 10 struct htb { struct tc tc; @@ -3555,7 +3556,7 @@ htb_setup_qdisc__(struct netdev *netdev) nl_msg_put_string(&request, TCA_KIND, "htb"); memset(&opt, 0, sizeof opt); - opt.rate2quantum = 10; + opt.rate2quantum = HTB_RATE2QUANTUM; opt.version = 3; opt.defcls = 1; @@ -3589,6 +3590,9 @@ htb_setup_class__(struct netdev *netdev, unsigned int handle, memset(&opt, 0, sizeof opt); tc_fill_rate(&opt.rate, class->min_rate, mtu); tc_fill_rate(&opt.ceil, class->max_rate, mtu); + if ((class->min_rate / HTB_RATE2QUANTUM) < mtu) { + opt.quantum = mtu; + } opt.buffer = tc_calc_buffer(opt.rate.rate, mtu, class->burst); opt.cbuffer = tc_calc_buffer(opt.ceil.rate, mtu, class->burst); opt.prio = class->priority; -- 1.7.9.5 _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
