There are multiple problems related to qlen adjustment that can lead to an upper qdisc getting out of sync with the real number of packets queued, leading to endless dequeueing attempts by the upper layer code. All qdiscs must maintain an accurate q.qlen counter. There are basically two groups of operations affecting the qlen: operations that propagate down the tree (enqueue, dequeue, requeue, drop, reset) beginning at the root qdisc and operations only affecting a subtree or single qdisc (change, graft, delete class). Since qlen changes during operations from the second group don't propagate to ancestor qdiscs, their qlen values become desynchronized. This patch adds a function to propagate qlen changes up the qdisc tree, optionally calling a callback function to perform qdisc-internal maintenance when the child qdisc becomes empty. The follow-up patches will convert all qdiscs to use this function where necessary. Noticed by Timo Steinbach <tsteinbach@astaro.com>. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net> |
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802 | ||
8021q | ||
appletalk | ||
atm | ||
ax25 | ||
bluetooth | ||
bridge | ||
core | ||
dccp | ||
decnet | ||
econet | ||
ethernet | ||
ieee80211 | ||
ipv4 | ||
ipv6 | ||
ipx | ||
irda | ||
key | ||
lapb | ||
llc | ||
netfilter | ||
netlabel | ||
netlink | ||
netrom | ||
packet | ||
rose | ||
rxrpc | ||
sched | ||
sctp | ||
sunrpc | ||
tipc | ||
unix | ||
wanrouter | ||
x25 | ||
xfrm | ||
compat.c | ||
Kconfig | ||
Makefile | ||
nonet.c | ||
socket.c | ||
sysctl_net.c | ||
TUNABLE |