GCC refuses to recognize that all error control flows do in fact
set err to something.
Add an explicit initialization to shut it up.
net/sched/sch_drr.c: In function ‘drr_enqueue’:
net/sched/sch_drr.c:359:11: warning: ‘err’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/sched/sch_qfq.c: In function ‘qfq_enqueue’:
net/sched/sch_qfq.c:885:11: warning: ‘err’ may be used uninitialized in this function [-Wmaybe-uninitialized]
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently use a per socket order-0 page cache for tcp_sendmsg()
operations.
This page is used to build fragments for skbs.
Its done to increase probability of coalescing small write() into
single segments in skbs still in write queue (not yet sent)
But it wastes a lot of memory for applications handling many mostly
idle sockets, since each socket holds one page in sk->sk_sndmsg_page
Its also quite inefficient to build TSO 64KB packets, because we need
about 16 pages per skb on arches where PAGE_SIZE = 4096, so we hit
page allocator more than wanted.
This patch adds a per task frag allocator and uses bigger pages,
if available. An automatic fallback is done in case of memory pressure.
(up to 32768 bytes per frag, thats order-3 pages on x86)
This increases TCP stream performance by 20% on loopback device,
but also benefits on other network devices, since 8x less frags are
mapped on transmit and unmapped on tx completion. Alexander Duyck
mentioned a probable performance win on systems with IOMMU enabled.
Its possible some SG enabled hardware cant cope with bigger fragments,
but their ndo_start_xmit() should already handle this, splitting a
fragment in sub fragments, since some arches have PAGE_SIZE=65536
Successfully tested on various ethernet devices.
(ixgbe, igb, bnx2x, tg3, mellanox mlx4)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
Currently, cgroup hierarchy support is a mess. cpu related subsystems
behave correctly - configuration, accounting and control on a parent
properly cover its children. blkio and freezer completely ignore
hierarchy and treat all cgroups as if they're directly under the root
cgroup. Others show yet different behaviors.
These differing interpretations of cgroup hierarchy make using cgroup
confusing and it impossible to co-mount controllers into the same
hierarchy and obtain sane behavior.
Eventually, we want full hierarchy support from all subsystems and
probably a unified hierarchy. Users using separate hierarchies
expecting completely different behaviors depending on the mounted
subsystem is deterimental to making any progress on this front.
This patch adds cgroup_subsys.broken_hierarchy and sets it to %true
for controllers which are lacking in hierarchy support. The goal of
this patch is two-fold.
* Move users away from using hierarchy on currently non-hierarchical
subsystems, so that implementing proper hierarchy support on those
doesn't surprise them.
* Keep track of which controllers are broken how and nudge the
subsystems to implement proper hierarchy support.
For now, start with a single warning message. We can whine louder
later on.
v2: Fixed a typo spotted by Michal. Warning message updated.
v3: Updated memcg part so that it doesn't generate warning in the
cases where .use_hierarchy=false doesn't make the behavior
different from root.use_hierarchy=true. Fixed a typo spotted by
Glauber.
v4: Check ->broken_hierarchy after cgroup creation is complete so that
->create() can affect the result per Michal. Dropped unnecessary
memcg root handling per Michal.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
WARNING: With this change it is impossible to load external built
controllers anymore.
In case where CONFIG_NETPRIO_CGROUP=m and CONFIG_NET_CLS_CGROUP=m is
set, corresponding subsys_id should also be a constant. Up to now,
net_prio_subsys_id and net_cls_subsys_id would be of the type int and
the value would be assigned during runtime.
By switching the macro definition IS_SUBSYS_ENABLED from IS_BUILTIN
to IS_ENABLED, all *_subsys_id will have constant value. That means we
need to remove all the code which assumes a value can be assigned to
net_prio_subsys_id and net_cls_subsys_id.
A close look is necessary on the RCU part which was introduces by
following patch:
commit f845172531
Author: Herbert Xu <herbert@gondor.apana.org.au> Mon May 24 09:12:34 2010
Committer: David S. Miller <davem@davemloft.net> Mon May 24 09:12:34 2010
cls_cgroup: Store classid in struct sock
Tis code was added to init_cgroup_cls()
/* We can't use rcu_assign_pointer because this is an int. */
smp_wmb();
net_cls_subsys_id = net_cls_subsys.subsys_id;
respectively to exit_cgroup_cls()
net_cls_subsys_id = -1;
synchronize_rcu();
and in module version of task_cls_classid()
rcu_read_lock();
id = rcu_dereference(net_cls_subsys_id);
if (id >= 0)
classid = container_of(task_subsys_state(p, id),
struct cgroup_cls_state, css)->classid;
rcu_read_unlock();
Without an explicit explaination why the RCU part is needed. (The
rcu_deference was fixed by exchanging it to rcu_derefence_index_check()
in a later commit, but that is a minor detail.)
So here is my pondering why it was introduced and why it safe to
remove it now. Note that this code was copied over to net_prio the
reasoning holds for that subsystem too.
The idea behind the RCU use for net_cls_subsys_id is to make sure we
get a valid pointer back from task_subsys_state(). task_subsys_state()
is just blindly accessing the subsys array and returning the
pointer. Obviously, passing in -1 as id into task_subsys_state()
returns an invalid value (out of lower bound).
So this code makes sure that only after module is loaded and the
subsystem registered, the id is assigned.
Before unregistering the module all old readers must have left the
critical section. This is done by assigning -1 to the id and issuing a
synchronized_rcu(). Any new readers wont call task_subsys_state()
anymore and therefore it is safe to unregister the subsystem.
The new code relies on the same trick, but it looks at the subsys
pointer return by task_subsys_state() (remember the id is constant
and therefore we allways have a valid index into the subsys
array).
No precautions need to be taken during module loading
module. Eventually, all CPUs will get a valid pointer back from
task_subsys_state() because rebind_subsystem() which is called after
the module init() function will assigned subsys[net_cls_subsys_id] the
newly loaded module subsystem pointer.
When the subsystem is about to be removed, rebind_subsystem() will
called before the module exit() function. In this case,
rebind_subsys() will assign subsys[net_cls_subsys_id] a NULL pointer
and then it calls synchronize_rcu(). All old readers have left by then
the critical section. Any new reader wont access the subsystem
anymore. At this point we are safe to unregister the subsystem. No
synchronize_rcu() call is needed.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
gred_dequeue() and gred_drop() do not seem to get called when the
queue is empty, meaning that we never start idling while in WRED
mode. And since qidlestart is not stored by gred_store_wred_set(),
we would never stop idling while in WRED mode if we ever started.
This messes up the average queue size calculation that influences
packet marking/dropping behavior.
Now, we start WRED mode idling as we are removing the last packet
from the queue. Also we now actually stop WRED mode idling when we
are enqueuing a packet.
Cc: Bruce Osler <brosler@cisco.com>
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
q->vars.qavg is a Wlog scaled value, but q->backlog is not. In order
to pass q->vars.qavg as the backlog value, we need to un-scale it.
Additionally, the qave value returned via netlink should not be Wlog
scaled, so we need to un-scale the result of red_calc_qavg().
This caused artificially high values for "Average Queue" to be shown
by 'tc -s -d qdisc', but did not affect the actual operation of GRED.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each pair of DPs only needs to be compared once when searching for
a non-unique prio value.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its possible to setup a bad cbq configuration leading to
an infinite loop in cbq_classify()
DEV_OUT=eth0
ICMP="match ip protocol 1 0xff"
U32="protocol ip u32"
DST="match ip dst"
tc qdisc add dev $DEV_OUT root handle 1: cbq avpkt 1000 \
bandwidth 100mbit
tc class add dev $DEV_OUT parent 1: classid 1:1 cbq \
rate 512kbit allot 1500 prio 5 bounded isolated
tc filter add dev $DEV_OUT parent 1: prio 3 $U32 \
$ICMP $DST 192.168.3.234 flowid 1:
Reported-by: Denys Fedoryschenko <denys@visp.net.lb>
Tested-by: Denys Fedoryschenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.
I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.
I have successfully built an allyesconfig kernel with this change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When fq_codel builds a new flow, it should not reset codel state.
Codel algo needs to get previous values (lastcount, drop_next) to get
proper behavior.
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Dave Taht <dave.taht@bufferbloat.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
We drop packet unconditionally when we fail to mirror it. This is not intended
in some cases. Consdier for kvm guest, we may mirror the traffic of the bridge
to a tap device used by a VM. When kernel fails to mirror the packet in
conditions such as when qemu crashes or stop polling the tap, it's hard for the
management software to detect such condition and clean the the mirroring
before. This would lead all packets to the bridge to be dropped and break the
netowrk of other virtual machines.
To solve the issue, the patch does not drop packets when kernel fails to mirror
it, and only drop the redirected packets.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The flow classifier can use uids and gids of the sockets that
are transmitting packets and do insert those uids and gids
into the packet classification calcuation. I don't fully
understand the details but it appears that we can depend
on specific uids and gids when making traffic classification
decisions.
To work with user namespaces enabled map from kuids and kgids
into uids and gids in the initial user namespace giving raw
integer values the code can play with and depend on.
To avoid issues of userspace depending on uids and gids in
packet classifiers installed from other user namespaces
and getting confused deny all packet classifiers that
use uids or gids that are not comming from a netlink socket
in the initial user namespace.
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Changli Gao <xiaosuo@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
cls_flow.c plays with uids and gids. Unless I misread that
code it is possible for classifiers to depend on the specific uid and
gid values. Therefore I need to know the user namespace of the
netlink socket that is installing the packet classifiers. Pass
in the rtnetlink skb so I can access the NETLINK_CB of the passed
packet. In particular I want access to sk_user_ns(NETLINK_CB(in_skb).ssk).
Pass in not the user namespace but the incomming rtnetlink skb into
the the classifier change routines as that is generally the more useful
parameter.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
I believe net/core/dev.c is a better place for netif_notify_peers(),
because other net event notify functions also stay in this file.
And rename it to netdev_notify_peers().
Cc: David S. Miller <davem@davemloft.net>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[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.valente@unimore.it>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some action modules free struct tcf_common in their error path
while estimator is still active. This results in est_timer()
dereference freed memory.
Add gen_kill_estimator() in ipt, pedit and simple action.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gact_rand array is accessed by gact->tcfg_ptype whose value
is assumed to less than MAX_RAND, but any range checks are
not performed.
So add a check in tcf_gact_init(). And in tcf_gact(), we can
reduce a branch.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use inet_iif() consistently, and for TCP record the input interface of
cached RX dst in inet sock.
rt->rt_iif is going to be encoded differently, so that we can
legitimately cache input routes in the FIB info more aggressively.
When the input interface is "use SKB device index" the rt->rt_iif will
be set to zero.
This forces us to move the TCP RX dst cache installation into the ipv4
specific code, and as well it should since doing the route caching for
ipv6 is pointless at the moment since it is not inspected in the ipv6
input paths yet.
Also, remove the unlikely on dst->obsolete, all ipv4 dsts have
obsolete set to a non-zero value to force invocation of the check
callback.
Signed-off-by: David S. Miller <davem@davemloft.net>
netem does an early orphaning of skbs. Doing so breaks TCP Small Queue
or any mechanism relying on socket sk_wmem_alloc feedback.
Ideally, we should perform this orphaning after the rate module and
before the delay module, to mimic what happens on a real link :
skb orphaning is indeed normally done at TX completion, before the
transit on the link.
+-------+ +--------+ +---------------+ +-----------------+
+ Qdisc +---> Device +--> TX completion +--> links / hops +->
+ + + xmit + + skb orphaning + + propagation +
+-------+ +--------+ +---------------+ +-----------------+
< rate limiting > < delay, drops, reorders >
If netem is used without delay feature (drops, reorders, rate
limiting), then we should avoid early skb orphaning, to keep pressure
on sockets as long as packets are still in qdisc queue.
Ideally, netem should be refactored to implement delay module
as the last stage. Current algorithm merges the two phases
(rate limiting + delay) so its not correct.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Mark Gordon <msg@google.com>
Cc: Andreas Terzis <aterzis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44461
Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Can be used to match packets against netfilter ip sets created via ipset(8).
skb->sk_iif is used as 'incoming interface', skb->dev is 'outgoing interface'.
Since ipset is usually called from netfilter, the ematch
initializes a fake xt_action_param, pulls the ip header into the
linear area and also sets skb->data to the IP header (otherwise
matching Layer 4 set types doesn't work).
Tested-by: Mr Dash Four <mr.dash.four@googlemail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix two netem bugs :
1) When a frame was dropped by tfifo_enqueue(), drop counter
was incremented twice.
2) When reordering is triggered, we enqueue a packet without
checking queue limit. This can OOM pretty fast when this
is repeated enough, since skbs are orphaned, no socket limit
can help in this situation.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mark Gordon <msg@google.com>
Cc: Andreas Terzis <aterzis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This ematch makes it possible to classify CAN frames (AF_CAN) according
to their identifiers. This functionality can not be easily achieved with
existing classifiers, such as u32, because CAN identifier is always stored
in native endianness, whereas u32 expects Network byte order.
Signed-off-by: Rostislav Lisovy <lisovy@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
sockfd_lookup() is declared in linux/net.h, which is pulled by
linux/skbuff.h (and needed for a lot of other stuff in sch_atm.c
anyway).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The padding destination or hop-by-hop option is called Pad1 and not Pad0.
See RFC2460 (4.2) or the IANA ipv6-parameters registry:
http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xml
Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
codel_should_drop() logic allows a packet being not dropped if queue
size is under max packet size.
In fq_codel, we have two possible backlogs : The qdisc global one, and
the flow local one.
The meaningful one for codel_should_drop() should be the global backlog,
not the per flow one, so that thin flows can have a non zero drop/mark
probability.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Standardize the net core ratelimited logging functions.
Coalesce formats, align arguments.
Change a printk then vprintk sequence to use printf extension %pV.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the following build error:
net/sched/sch_fq_codel.c: In function 'fq_codel_dump_stats':
net/sched/sch_fq_codel.c:464:3: error: unknown field 'qdisc_stats' specified in initializer
net/sched/sch_fq_codel.c:464:3: warning: missing braces around initializer
net/sched/sch_fq_codel.c:464:3: warning: (near initialization for 'st.<anonymous>')
net/sched/sch_fq_codel.c:465:3: error: unknown field 'qdisc_stats' specified in initializer
net/sched/sch_fq_codel.c:465:3: warning: excess elements in struct initializer
net/sched/sch_fq_codel.c:465:3: warning: (near initialization for 'st')
net/sched/sch_fq_codel.c:466:3: error: unknown field 'qdisc_stats' specified in initializer
net/sched/sch_fq_codel.c:466:3: warning: excess elements in struct initializer
net/sched/sch_fq_codel.c:466:3: warning: (near initialization for 'st')
net/sched/sch_fq_codel.c:467:3: error: unknown field 'qdisc_stats' specified in initializer
net/sched/sch_fq_codel.c:467:3: warning: excess elements in struct initializer
net/sched/sch_fq_codel.c:467:3: warning: (near initialization for 'st')
make[1]: *** [net/sched/sch_fq_codel.o] Error 1
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
m68k allmodconfig:
net/sched/sch_codel.c: In function ‘dequeue’:
net/sched/sch_codel.c:70: error: implicit declaration of function ‘prefetch’
make[1]: *** [net/sched/sch_codel.o] Error 1
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An implementation of CoDel AQM, from Kathleen Nichols and Van Jacobson.
http://queue.acm.org/detail.cfm?id=2209336
This AQM main input is no longer queue size in bytes or packets, but the
delay packets stay in (FIFO) queue.
As we don't have infinite memory, we still can drop packets in enqueue()
in case of massive load, but mean of CoDel is to drop packets in
dequeue(), using a control law based on two simple parameters :
target : target sojourn time (default 5ms)
interval : width of moving time window (default 100ms)
Based on initial work from Dave Taht.
Refactored to help future codel inclusion as a plugin for other linux
qdisc (FQ_CODEL, ...), like RED.
include/net/codel.h contains codel algorithm as close as possible than
Kathleen reference.
net/sched/sch_codel.c contains the linux qdisc specific glue.
Separate structures permit a memory efficient implementation of fq_codel
(to be sent as a separate work) : Each flow has its own struct
codel_vars.
timestamps are taken at enqueue() time with 1024 ns precision, allowing
a range of 2199 seconds in queue, and 100Gb links support. iproute2 uses
usec as base unit.
Selected packets are dropped, unless ECN is enabled and packets can get
ECN mark instead.
Tested from 2Mb to 10Gb speeds with no particular problems, on ixgbe and
tg3 drivers (BQL enabled).
Usage: tc qdisc ... codel [ limit PACKETS ] [ target TIME ]
[ interval TIME ] [ ecn ]
qdisc codel 10: parent 1:1 limit 2000p target 3.0ms interval 60.0ms ecn
Sent 13347099587 bytes 8815805 pkt (dropped 0, overlimits 0 requeues 0)
rate 202365Kbit 16708pps backlog 113550b 75p requeues 0
count 116 lastcount 98 ldelay 4.3ms dropping drop_next 816us
maxpacket 1514 ecn_mark 84399 drop_overlimit 0
CoDel must be seen as a base module, and should be used keeping in mind
there is still a FIFO queue. So a typical setup will probably need a
hierarchy of several qdiscs and packet classifiers to be able to meet
whatever constraints a user might have.
One possible example would be to use fq_codel, which combines Fair
Queueing and CoDel, in replacement of sfq / sfq_red.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Class bytes/packets stats can be misleading because they are updated in
enqueue() while packet might be dropped later.
We already fixed all qdiscs but sch_atm.
This patch makes the final cleanup.
class rate estimators can now match qdisc ones.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_checksum_help(skb) can return an error, we must free skb in this
case. qdisc_drop(skb, sch) can also be feeded with a NULL skb (if
skb_unshare() failed), so lets use this generic helper.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ECN (Explicit Congestion Notification) marking capability to netem
tc qdisc add dev eth0 root netem drop 0.5 ecn
Instead of dropping packets, try to ECN mark them.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
A parameter set exists for WRED mode, called wred_set, to hold the same
values for qavg and qidlestart across all VQs. The WRED mode values had
been previously held in the VQ for the default DP. After these values
were moved to wred_set, the VQ for the default DP was no longer created
automatically (so that it could be omitted on purpose, to have packets
in the default DP enqueued directly to the device without using RED).
However, gred_dump() was overlooked during that change; in WRED mode it
still reads qavg/qidlestart from the VQ for the default DP, which might
not even exist. As a result, this command sequence will cause an oops:
tc qdisc add dev $DEV handle $HANDLE parent $PARENT gred setup \
DPs 3 default 2 grio
tc qdisc change dev $DEV handle $HANDLE gred DP 0 prio 8 $RED_OPTIONS
tc qdisc change dev $DEV handle $HANDLE gred DP 1 prio 8 $RED_OPTIONS
This fixes gred_dump() in WRED mode to use the values held in wred_set.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert debug, freezer, cpuset, cpu_cgroup, cpuacct, net_prio, blkio,
net_cls and device controllers to use the new cftype based interface.
Termination entry is added to cftype arrays and populate callbacks are
replaced with cgroup_subsys->base_cftypes initializations.
This is functionally identical transformation. There shouldn't be any
visible behavior change.
memcg is rather special and will be converted separately.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
blk-cgroup, netprio_cgroup, cls_cgroup and tcp_memcontrol
unnecessarily define cftype array and cgroup_subsys structures at the
top of the file, which is unconventional and necessiates forward
declaration of methods.
This patch relocates those below the definitions of the methods and
removes the forward declarations. Note that forward declaration of
tcp_files[] is added in tcp_memcontrol.c for tcp_init_cgroup(). This
will be removed soon by another patch.
This patch doesn't introduce any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
This reverts commit d47a0ac7b6 (sch_sfq: dont put new flow at the end of
flows)
As Jesper found out, patch sounded great but has bad side effects.
In stress situation, pushing new flows in front of the queue can prevent
old flows doing any progress. Packets can stay in SFQ queue for
unlimited amount of time.
It's possible to add heuristics to limit this problem, but this would
add complexity outside of SFQ scope.
A more sensible answer to Dave Taht concerns (who reported the issued I
tried to solve in original commit) is probably to use a qdisc hierarchy
so that high prio packets dont enter a potentially crowded SFQ qdisc.
Reported-by: Jesper Dangaard Brouer <jdb@comx.dk>
Cc: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 50612537e9 (netem: fix classful handling) added two errors in
netem_dequeue()
1) After checking skb at the head of tfifo queue for time constraints,
it dequeues tail skb, thus adding unwanted reordering.
2) qdisc stats are updated twice per packet
(one when packet dequeued from tfifo, once when delivered)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sched/sch_plug.c:211:18: warning: symbol 'plug_qdisc_ops' was not
declared. Should it be static?
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just like skb->cb[], so that qdisc_skb_cb can be encapsulated inside
of other data structures.
This is intended to be used by IPoIB so that it can remember
addressing information stored at hard_header_ops->create() time that
it can fetch when the packet gets to the transmit routine.
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller