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2012-10-10pkt_sched: fix virtual-start-time update in QFQPaolo Valente
[ Upstream commit 71261956973ba9e0637848a5adb4a5819b4bae83 ] If the old timestamps of a class, say cl, are stale when the class becomes active, then QFQ may assign to cl a much higher start time than the maximum value allowed. This may happen when QFQ assigns to the start time of cl the finish time of a group whose classes are characterized by a higher value of the ratio max_class_pkt/weight_of_the_class with respect to that of cl. Inserting a class with a too high start time into the bucket list corrupts the data structure and may eventually lead to crashes. This patch limits the maximum start time assigned to a class. Signed-off-by: Paolo Valente <paolo.valente@unimore.it> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-01-03sch_qfq: fix overflow in qfq_update_start()Eric Dumazet
grp->slot_shift is between 22 and 41, so using 32bit wide variables is probably a typo. This could explain QFQ hangs Dave reported to me, after 2^23 packets ? (23 = 64 - 41) Reported-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> CC: Dave Taht <dave.taht@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-04pkt_sched: QFQ - quick fair queue schedulerstephen hemminger
This is an implementation of the Quick Fair Queue scheduler developed by Fabio Checconi. The same algorithm is already implemented in ipfw in FreeBSD. Fabio had an earlier version developed on Linux, I just cleaned it up. Thanks to Eric Dumazet for testing this under load. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>