From: Paolo Valente <paolo.vale...@unimore.it> Date: Tue, 7 Aug 2012 19:27:25 +0200
> [Resending again, as the text was corrupted by the email client] > > To speed up operations, QFQ internally divides classes into > groups. Which group a class belongs to depends on the ratio between > the maximum packet length and the weight of the class. Unfortunately > the function qfq_change_class lacks the steps for changing the group > of a class when the ratio max_pkt_len/weight of the class changes. > > For example, when the last of the following three commands is > executed, the group of class 1:1 is not correctly changed: > > tc disc add dev XXX root handle 1: qfq > tc class add dev XXX parent 1: qfq classid 1:1 weight 1 > tc class change dev XXX parent 1: classid 1:1 qfq weight 4 > > Not changing the group of a class does not affect the long-term > bandwidth guaranteed to the class, as the latter is independent of the > maximum packet length, and correctly changes (only) if the weight of > the class changes. In contrast, if the group of the class is not > updated, the class is still guaranteed the short-term bandwidth and > packet delay related to its old group, instead of the guarantees that > it should receive according to its new weight and/or maximum packet > length. This may also break service guarantees for other classes. > This patch adds the missing operations. > > Signed-off-by: Paolo Valente <paolo.vale...@unimore.it> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
