This removes the use of qstats->qlen variable from the classifiers
and makes it an explicit argument to gnet_stats_copy_queue().
The qlen represents the qdisc queue length and is packed into
the qstats at the last moment before passnig to user space. By
handling it explicitely we avoid, in the percpu stats case, having
to figure out which per_cpu variable to put it in.
It would probably be best to remove it from qstats completely
but qstats is a user space ABI and can't be broken. A future
patch could make an internal only qstats structure that would
avoid having to allocate an additional u32 variable on the
Qdisc struct. This would make the qstats struct 128bits instead
of 128+32.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds helpers to manipulate qstats logic and replaces locations
that touch the counters directly. This simplifies future patches
to push qstats onto per cpu counters.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to run qdisc's without locking statistics and estimators
need to be handled correctly.
To resolve bstats make the statistics per cpu. And because this is
only needed for qdiscs that are running without locks which is not
the case for most qdiscs in the near future only create percpu
stats when qdiscs set the TCQ_F_CPUSTATS flag.
Next because estimators use the bstats to calculate packets per
second and bytes per second the estimator code paths are updated
to use the per cpu statistics.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This completes the cls_rsvp conversion to RCU safe
copy, update semantics.
As a result all cases of tcf_exts_change occur on
empty lists now.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Clearly the following change is not expected:
- if (!cp.perfect && !cp.h)
- cp.alloc_hash = cp.hash;
+ if (!cp->perfect && cp->h)
+ cp->alloc_hash = cp->hash;
Fixes: commit 331b72922c ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When kmemdup() fails, we should return -ENOMEM.
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <hadi@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While using a MQ + NETEM setup, I had confirmation that the default
timer migration ( /proc/sys/kernel/timer_migration ) is killing us.
Installing this on a receiver side of a TCP_STREAM test, (NIC has 8 TX
queues) :
EST="est 1sec 4sec"
for ETH in eth1
do
tc qd del dev $ETH root 2>/dev/null
tc qd add dev $ETH root handle 1: mq
tc qd add dev $ETH parent 1:1 $EST netem limit 70000 delay 6ms
tc qd add dev $ETH parent 1:2 $EST netem limit 70000 delay 8ms
tc qd add dev $ETH parent 1:3 $EST netem limit 70000 delay 10ms
tc qd add dev $ETH parent 1:4 $EST netem limit 70000 delay 12ms
tc qd add dev $ETH parent 1:5 $EST netem limit 70000 delay 14ms
tc qd add dev $ETH parent 1:6 $EST netem limit 70000 delay 16ms
tc qd add dev $ETH parent 1:7 $EST netem limit 80000 delay 18ms
tc qd add dev $ETH parent 1:8 $EST netem limit 90000 delay 20ms
done
We can see that timers get migrated into a single cpu, presumably idle
at the time timers are set up.
Then all qdisc dequeues run from this cpu and huge lock contention
happens. This single cpu is stuck in softirq mode and cannot dequeue
fast enough.
39.24% [kernel] [k] _raw_spin_lock
2.65% [kernel] [k] netem_enqueue
1.80% [kernel] [k] netem_dequeue
1.63% [kernel] [k] copy_user_enhanced_fast_string
1.45% [kernel] [k] _raw_spin_lock_bh
By pinning qdisc timers on the cpu running the qdisc, we respect proper
XPS setting and remove this lock contention.
5.84% [kernel] [k] netem_enqueue
4.83% [kernel] [k] _raw_spin_lock
2.92% [kernel] [k] copy_user_enhanced_fast_string
Current Qdiscs that benefit from this change are :
netem, cbq, fq, hfsc, tbf, htb.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
arch/mips/net/bpf_jit.c
drivers/net/can/flexcan.c
Both the flexcan and MIPS bpf_jit conflicts were cases of simple
overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
$ grep CONFIG_CLS_U32_MARK .config
# CONFIG_CLS_U32_MARK is not set
net/sched/cls_u32.c: In function 'u32_change':
net/sched/cls_u32.c:852:1: warning: label 'errout' defined but not used
[-Wunused-label]
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changes to the cls_u32 classifier must appear atomic to the
readers. Before this patch if a change is requested for both
the exts and ifindex, first the ifindex is updated then the
exts with tcf_exts_change(). This opens a small window where
a reader can have a exts chain with an incorrect ifindex. This
violates the the RCU semantics.
Here we resolve this by always passing u32_set_parms() a copy
of the tc_u_knode to work on and then inserting it into the hash
table after the updates have been successfully applied.
Tested with the following short script:
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 handle 1: \
u32 divisor 256
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 \
u32 link 1: hashkey mask ffffff00 at 12 \
match ip src 192.168.8.0/2
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 102 \
handle 1::10 u32 classid 1:2 ht 1: \
match ip src 192.168.8.0/8 match ip tos 0x0a 1e
#tc filter change dev p3p2 parent 8001:0 protocol ip prio 102 \
handle 1::10 u32 classid 1:2 ht 1: \
match ip src 1.1.0.0/8 match ip tos 0x0b 1e
CC: Eric Dumazet <edumazet@google.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes a missed free_percpu in the unwind code path and when
keys are destroyed.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We cannot make struct qdisc_skb_cb bigger without impacting IPoIB,
or increasing skb->cb[] size.
Commit e0f31d8498 ("flow_keys: Record IP layer protocol in
skb_flow_dissect()") broke IPoIB.
Only current offender is sch_choke, and this one do not need an
absolutely precise flow key.
If we store 17 bytes of flow key, its more than enough. (Its the actual
size of flow_keys if it was a packed structure, but we might add new
fields at the end of it later)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: e0f31d8498 ("flow_keys: Record IP layer protocol in skb_flow_dissect()")
Signed-off-by: David S. Miller <davem@davemloft.net>
tc_u32_sel 'sel' in tc_u_knode expects to be the last element in the
structure and pads the structure with tc_u32_key fields for each key.
kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL)
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pfifo_fast and htb use skb lists, without needing their spinlocks.
(They instead use the standard qdisc lock)
We can use __skb_queue_head_init() instead of skb_queue_head_init()
to be consistent.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This ensures the tcf_exts_init() is called for all cases.
Fixes: 952313bd62 ("net: sched: cls_cgroup use RCU")
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When allocating a new structure we also need to call tcf_exts_init
to initialize exts.
A follow up patch might be in order to remove some of this code
and do tcf_exts_assign(). With this we could remove the
tcf_exts_init/tcf_exts_change pattern for some of the classifiers.
As part of the future tcf_actions RCU series this will need to be
done. For now fix the call here.
Fixes e35a8ee599 ("net: sched: fw use RCU")
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tree: git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git master
head: 54996b529a
commit: c7953ef230 [625/646] net: sched: cls_cgroup use RCU
net/sched/cls_cgroup.c:130 cls_cgroup_change() warn: possible memory leak of 'new'
net/sched/cls_cgroup.c:135 cls_cgroup_change() warn: possible memory leak of 'new'
net/sched/cls_cgroup.c:139 cls_cgroup_change() warn: possible memory leak of 'new'
Fixes: c7953ef230 ("net: sched: cls_cgroup use RCU")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kbuild test robot reported an unused variable cpu in cls_u32.c
after the patch below. This happens when PERF and MARK config
variables are disabled
Fix this is to use separate variables for perf and mark
and define the cpu variable inside the ifdef logic.
Fixes: 459d5f626d ("net: sched: make cls_u32 per cpu")'
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: commit 331b72922c ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-By: John Fastabend <john.r.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: commit 331b72922c ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: commit 331b72922c ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: commit 1f947bf151 ("net: sched: rcu'ify cls_bpf")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes the cls_bpf classifier RCU safe. The tcf_lock
was being used to protect a list of cls_bpf_prog now this list
is RCU safe and updates occur with rcu_replace.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make cls_u32 classifier safe to run without holding lock. This patch
converts statistics that are kept in read section u32_classify into
per cpu counters.
This patch was tested with a tight u32 filter add/delete loop while
generating traffic with pktgen. By running pktgen on vlan devices
created on top of a physical device we can hit the qdisc layer
correctly. For ingress qdisc's a loopback cable was used.
for i in {1..100}; do
q=`echo $i%8|bc`;
echo -n "u32 tos: iteration $i on queue $q";
tc filter add dev p3p2 parent $p prio $i u32 match ip tos 0x10 0xff \
action skbedit queue_mapping $q;
sleep 1;
tc filter del dev p3p2 prio $i;
echo -n "u32 tos hash table: iteration $i on queue $q";
tc filter add dev p3p2 parent $p protocol ip prio $i handle 628: u32 divisor 1
tc filter add dev p3p2 parent $p protocol ip prio $i u32 \
match ip protocol 17 0xff link 628: offset at 0 mask 0xf00 shift 6 plus 0
tc filter add dev p3p2 parent $p protocol ip prio $i u32 \
ht 628:0 match ip tos 0x10 0xff action skbedit queue_mapping $q
sleep 2;
tc filter del dev p3p2 prio $i
sleep 1;
done
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This uses per cpu counters in cls_u32 in preparation
to convert over to rcu.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make cls_tcindex RCU safe.
This patch addds a new RCU routine rcu_dereference_bh_rtnl() to check
caller either holds the rcu read lock or RTNL. This is needed to
handle the case where tcindex_lookup() is being called in both cases.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RCUify the route classifier. For now however spinlock's are used to
protect fastmap cache.
The issue here is the fastmap may be read by one CPU while the
cache is being updated by another. An array of pointers could be
one possible solution.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RCU'ify fw classifier.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make cgroup classifier safe for RCU.
Also drops the calls in the classify routine that were doing a
rcu_read_lock()/rcu_read_unlock(). If the rcu_read_lock() isn't held
entering this routine we have issues with deleting the classifier
chain so remove the unnecessary rcu_read_lock()/rcu_read_unlock()
pair noting all paths AFAIK hold rcu_read_lock.
If there is a case where classify is called without the rcu read lock
then an rcu splat will occur and we can correct it.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Enable basic classifier for RCU.
Dereferencing tp->root may look a bit strange here but it is needed
by my accounting because it is allocated at init time and needs to
be kfree'd at destroy time. However because it may be referenced in
the classify() path we must wait an RCU grace period before free'ing
it. We use kfree_rcu() and rcu_ APIs to enforce this. This pattern
is used in all the classifiers.
Also the hgenerator can be incremented without concern because it
is always incremented under RTNL.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rcu'ify tcf_proto this allows calling tc_classify() without holding
any locks. Updaters are protected by RTNL.
This patch prepares the core net_sched infrastracture for running
the classifier/action chains without holding the qdisc lock however
it does nothing to ensure cls_xxx and act_xxx types also work without
locking. Additional patches are required to address the fall out.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add __rcu notation to qdisc handling by doing this we can make
smatch output more legible. And anyways some of the cases should
be using rcu_dereference() see qdisc_all_tx_empty(),
qdisc_tx_chainging(), and so on.
Also *wake_queue() API is commonly called from driver timer routines
without rcu lock or rtnl lock. So I added rcu_read_lock() blocks
around netif_wake_subqueue and netif_tx_wake_queue.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
not used anymore since ddecf0f
(net_sched: sfq: add optional RED on top of SFQ).
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
More minor fixes to merge commit 53fda7f7f9 (Merge branch 'xmit_list')
that allows us to work with a list of SKBs.
Fixing exit cases in qdisc_reset() and qdisc_destroy(), where a
leftover requeued SKB (qdisc->gso_skb) can have the potential of
being a skb list, thus use kfree_skb_list().
This is a followup to commit 10770bc2d1 ("qdisc: adjustments for
API allowing skb list xmits").
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor adjustments for merge commit 53fda7f7f9 (Merge branch 'xmit_list')
that allows us to work with a list of SKBs.
Update code doc to function sch_direct_xmit().
In handle_dev_cpu_collision() use kfree_skb_list() in error handling.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just maintain the list properly by returning the head of the remaining
SKB list from dev_hard_start_xmit().
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace occurences of skb_get_queue_mapping() and follow-up
netdev_get_tx_queue() with an actual helper function.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace open codings of (((u64) <x> * <y>) >> 32) with reciprocal_scale().
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
ktime_get_ns() replaces ktime_to_ns(ktime_get())
ktime_get_real_ns() replaces ktime_to_ns(ktime_get_real())
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
John Fastabend