Граф коммитов

161 Коммитов

Автор SHA1 Сообщение Дата
Eric Dumazet 3e1e3aae1f net_sched: add u64 rate to psched_ratecfg_precompute()
Add an extra u64 rate parameter to psched_ratecfg_precompute()
so that some qdisc can opt-in for 64bit rates in the future,
to overcome the ~34 Gbits limit.

psched_ratecfg_getrate() reports a legacy structure to
tc utility, so if actual rate is above the 32bit rate field,
cap it to the 34Gbit limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-20 14:41:02 -04:00
stephen hemminger 34aedd3f3b qdisc: fix build with !CONFIG_NET_SCHED
Multiqueue scheduler refers to default_qdisc_ops; therefore the
variable definition needs to be moved to handle case where net
scheduler API is not available.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31 18:09:45 -04:00
stephen hemminger d2a7f269f9 qdisc: make args to qdisc_create_default const
Fixes warnings introduced by the qdisc default patch.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31 18:09:45 -04:00
stephen hemminger 6da7c8fcbc qdisc: allow setting default queuing discipline
By default, the pfifo_fast queue discipline has been used by default
for all devices. But we have better choices now.

This patch allow setting the default queueing discipline with sysctl.
This allows easy use of better queueing disciplines on all devices
without having to use tc qdisc scripts. It is intended to allow
an easy path for distributions to make fq_codel or sfq the default
qdisc.

This patch also makes pfifo_fast more of a first class qdisc, since
it is now possible to manually override the default and explicitly
use pfifo_fast. The behavior for systems who do not use the sysctl
is unchanged, they still get pfifo_fast

Also removes leftover random # in sysctl net core.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31 00:32:32 -04:00
Jesper Dangaard Brouer 8a8e3d84b1 net_sched: restore "linklayer atm" handling
commit 56b765b79 ("htb: improved accuracy at high rates")
broke the "linklayer atm" handling.

 tc class add ... htb rate X ceil Y linklayer atm

The linklayer setting is implemented by modifying the rate table
which is send to the kernel.  No direct parameter were
transferred to the kernel indicating the linklayer setting.

The commit 56b765b79 ("htb: improved accuracy at high rates")
removed the use of the rate table system.

To keep compatible with older iproute2 utils, this patch detects
the linklayer by parsing the rate table.  It also supports future
versions of iproute2 to send this linklayer parameter to the
kernel directly. This is done by using the __reserved field in
struct tc_ratespec, to convey the choosen linklayer option, but
only using the lower 4 bits of this field.

Linklayer detection is limited to speeds below 100Mbit/s, because
at high rates the rtab is gets too inaccurate, so bad that
several fields contain the same values, this resembling the ATM
detect.  Fields even start to contain "0" time to send, e.g. at
1000Mbit/s sending a 96 bytes packet cost "0", thus the rtab have
been more broken than we first realized.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-15 01:43:08 -07:00
nikolay@redhat.com 07ce76aa9b net_sched: make dev_trans_start return vlan's real dev trans_start
Vlan devices are LLTX and don't update their own trans_start, so if
dev_trans_start has to be called with a vlan device then 0 or a stale
value will be returned. Currently the bonding is the only such user, and
it's needed for proper arp monitoring when the slaves are vlans.
Fix this by extracting the vlan's real device trans_start.

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-05 12:17:42 -07:00
Eric Dumazet 130d3d68b5 net_sched: psched_ratecfg_precompute() improvements
Before allowing 64bits bytes rates, refactor
psched_ratecfg_precompute() to get better comments
and increased accuracy.

rate_bps field is renamed to rate_bytes_ps, as we only
have to worry about bytes per second.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-11 22:39:47 -07:00
Eric Dumazet 01cb71d2d4 net_sched: restore "overhead xxx" handling
commit 56b765b79 ("htb: improved accuracy at high rates")
broke the "overhead xxx" handling, as well as the "linklayer atm"
attribute.

tc class add ... htb rate X ceil Y linklayer atm overhead 10

This patch restores the "overhead xxx" handling, for htb, tbf
and act_police

The "linklayer atm" thing needs a separate fix.

Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vimalkumar <j.vimal@gmail.com>
Cc: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-02 22:22:35 -07:00
Sergey Popovich ea872d7712 sch: add missing u64 in psched_ratecfg_precompute()
It seems that commit

commit 292f1c7ff6
Author: Jiri Pirko <jiri@resnulli.us>
Date:   Tue Feb 12 00:12:03 2013 +0000

    sch: make htb_rate_cfg and functions around that generic

adds little regression.

Before:

# tc qdisc add dev eth0 root handle 1: htb default ffff
# tc class add dev eth0 classid 1:ffff htb rate 5Gbit
# tc -s class show dev eth0
class htb 1:ffff root prio 0 rate 5000Mbit ceil 5000Mbit burst 625b cburst
625b
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 rate 0bit 0pps backlog 0b 0p requeues 0
 lended: 0 borrowed: 0 giants: 0
 tokens: 31 ctokens: 31

After:

# tc qdisc add dev eth0 root handle 1: htb default ffff
# tc class add dev eth0 classid 1:ffff htb rate 5Gbit
# tc -s class show dev eth0
class htb 1:ffff root prio 0 rate 1544Mbit ceil 1544Mbit burst 625b cburst
625b
 Sent 5073 bytes 41 pkt (dropped 0, overlimits 0 requeues 0)
 rate 1976bit 2pps backlog 0b 0p requeues 0
 lended: 41 borrowed: 0 giants: 0
 tokens: 1802 ctokens: 1802

This probably due to lost u64 cast of rate parameter in
psched_ratecfg_precompute() (net/sched/sch_generic.c).

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-27 14:06:41 -04:00
Jiri Pirko 292f1c7ff6 sch: make htb_rate_cfg and functions around that generic
As it is going to be used in tbf as well, push these to generic code.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-12 18:59:45 -05:00
Eric Dumazet 1abbe1394a pkt_sched: avoid requeues if possible
With BQL being deployed, we can more likely have following behavior :

We dequeue a packet from qdisc in dequeue_skb(), then we realize target
tx queue is in XOFF state in sch_direct_xmit(), and we have to hold the
skb into gso_skb for later.

This shows in stats (tc -s qdisc dev eth0) as requeues.

Problem of these requeues is that high priority packets can not be
dequeued as long as this (possibly low prio and big TSO packet) is not
removed from gso_skb.

At 1Gbps speed, a full size TSO packet is 500 us of extra latency.

In some cases, we know that all packets dequeued from a qdisc are
for a particular and known txq :

- If device is non multi queue
- For all MQ/MQPRIO slave qdiscs

This patch introduces a new qdisc flag, TCQ_F_ONETXQUEUE to mark
this capability, so that dequeue_skb() is allowed to dequeue a packet
only if the associated txq is not stopped.

This indeed reduce latencies for high prio packets (or improve fairness
with sfq/fq_codel), and almost remove qdisc 'requeues'.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-12 00:16:47 -05:00
Eric Dumazet 23d3b8bfb8 net: qdisc busylock needs lockdep annotations
It seems we need to provide ability for stacked devices
to use specific lock_class_key for sch->busylock

We could instead default l2tpeth tx_queue_len to 0 (no qdisc), but
a user might use a qdisc anyway.

(So same fixes are probably needed on non LLTX stacked drivers)

Noticed while stressing L2TPV3 setup :

======================================================
 [ INFO: possible circular locking dependency detected ]
 3.6.0-rc3+ #788 Not tainted
 -------------------------------------------------------
 netperf/4660 is trying to acquire lock:
  (l2tpsock){+.-...}, at: [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]

 but task is already holding lock:
  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&(&sch->busylock)->rlock){+.-...}:
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817499fc>] _raw_spin_lock_irqsave+0x4c/0x60
        [<ffffffff81074872>] __wake_up+0x32/0x70
        [<ffffffff8136d39e>] tty_wakeup+0x3e/0x80
        [<ffffffff81378fb3>] pty_write+0x73/0x80
        [<ffffffff8136cb4c>] tty_put_char+0x3c/0x40
        [<ffffffff813722b2>] process_echoes+0x142/0x330
        [<ffffffff813742ab>] n_tty_receive_buf+0x8fb/0x1230
        [<ffffffff813777b2>] flush_to_ldisc+0x142/0x1c0
        [<ffffffff81062818>] process_one_work+0x198/0x760
        [<ffffffff81063236>] worker_thread+0x186/0x4b0
        [<ffffffff810694d3>] kthread+0x93/0xa0
        [<ffffffff81753e24>] kernel_thread_helper+0x4/0x10

 -> #0 (l2tpsock){+.-...}:
        [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
        [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
        [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
        [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
        [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
        [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
        [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
        [<ffffffff815db019>] ip_output+0x59/0xf0
        [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
        [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
        [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
        [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
        [<ffffffff815f5300>] tcp_push_one+0x30/0x40
        [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
        [<ffffffff81614495>] inet_sendmsg+0x125/0x230
        [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
        [<ffffffff81579ece>] sys_sendto+0xfe/0x130
        [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b
  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&(&sch->busylock)->rlock);
                                lock(l2tpsock);
                                lock(&(&sch->busylock)->rlock);
   lock(l2tpsock);

  *** DEADLOCK ***

 5 locks held by netperf/4660:
  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff815e581c>] tcp_sendmsg+0x2c/0x1040
  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff815da3e0>] ip_queue_xmit+0x0/0x680
  #2:  (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9ac5>] ip_finish_output+0x135/0x890
  #3:  (rcu_read_lock_bh){.+....}, at: [<ffffffff81595820>] dev_queue_xmit+0x0/0xe00
  #4:  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 stack backtrace:
 Pid: 4660, comm: netperf Not tainted 3.6.0-rc3+ #788
 Call Trace:
  [<ffffffff8173dbf8>] print_circular_bug+0x1fb/0x20c
  [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
  [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0
  [<ffffffff810a3f44>] ? __lock_acquire+0x2e4/0x1b10
  [<ffffffff810a5df0>] lock_acquire+0x90/0x200
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
  [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
  [<ffffffff81594e0e>] ? dev_hard_start_xmit+0x5e/0xa70
  [<ffffffff81595961>] ? dev_queue_xmit+0x141/0xe00
  [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
  [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
  [<ffffffff81595820>] ? dev_hard_start_xmit+0xa70/0xa70
  [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
  [<ffffffff815d9ac5>] ? ip_finish_output+0x135/0x890
  [<ffffffff815db019>] ip_output+0x59/0xf0
  [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
  [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
  [<ffffffff815da3e0>] ? ip_local_out+0xa0/0xa0
  [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
  [<ffffffff815fa25e>] ? tcp_md5_do_lookup+0x18e/0x1a0
  [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
  [<ffffffff815f5300>] tcp_push_one+0x30/0x40
  [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
  [<ffffffff81614495>] inet_sendmsg+0x125/0x230
  [<ffffffff81614370>] ? inet_create+0x6b0/0x6b0
  [<ffffffff8157e6e2>] ? sock_update_classid+0xc2/0x3b0
  [<ffffffff8157e750>] ? sock_update_classid+0x130/0x3b0
  [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
  [<ffffffff81162579>] ? fget_light+0x3f9/0x4f0
  [<ffffffff81579ece>] sys_sendto+0xfe/0x130
  [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10
  [<ffffffff8174a0b0>] ? _raw_spin_unlock_irq+0x30/0x50
  [<ffffffff810757e3>] ? finish_task_switch+0x83/0xf0
  [<ffffffff810757a6>] ? finish_task_switch+0x46/0xf0
  [<ffffffff81752cb7>] ? sysret_check+0x1b/0x56
  [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-05 17:49:27 -04:00
Amerigo Wang ee89bab14e net: move and rename netif_notify_peers()
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>
2012-08-14 14:28:23 -07:00
Joe Perches e87cc4728f net: Convert net_ratelimit uses to net_<level>_ratelimited
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>
2012-05-15 13:45:03 -04:00
David S. Miller 1b34ec43c9 pkt_sched: Stop using NLA_PUT*().
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>
2012-04-01 18:11:37 -04:00
Tom Herbert 7346649826 net: Add queue state xoff flag for stack
Create separate queue state flags so that either the stack or drivers
can turn on XOFF.  Added a set of functions used in the stack to determine
if a queue is really stopped (either by stack or driver)

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 12:46:19 -05:00
david decotigny ccf5ff69fb net: new counter for tx_timeout errors in sysfs
This adds the /sys/class/net/DEV/queues/Q/tx_timeout attribute
containing the total number of timeout events on the given queue. It
is always available with CONFIG_SYSFS, independently of
CONFIG_RPS/XPS.

Credits to Stephen Hemminger for a preliminary version of this patch.

Tested:
  without CONFIG_SYSFS (compilation only)
  with sysfs and without CONFIG_RPS & CONFIG_XPS
  with sysfs and without CONFIG_RPS
  with sysfs and without CONFIG_XPS
  with defaults

Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-16 23:14:02 -05:00
Krishna Kumar f0c50c7c9a Remove redundant variable/code in __qdisc_run
Remove redundant variable "work".

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-15 08:08:26 -07:00
jamal d5b8aa1d24 net_sched: fix dequeuer fairness
Results on dummy device can be seen in my netconf 2011
slides. These results are for a 10Gige IXGBE intel
nic - on another i5 machine, very similar specs to
the one used in the netconf2011 results.
It turns out - this is a hell lot worse than dummy
and so this patch is even more beneficial for 10G.

Test setup:
----------

System under test sending packets out.
Additional box connected directly dropping packets.
Installed prio qdisc on the eth device and default
netdev default length of 1000 used as is.
The 3 prio bands each were set to 100 (didnt factor in
the results).

5 packet runs were made and the middle 3 picked.

results
-------

The "cpu" column indicates the which cpu the sample
was taken on,
The "Pkt runx" carries the number of packets a cpu
dequeued when forced to be in the "dequeuer" role.
The "avg" for each run is the number of times each
cpu should be a "dequeuer" if the system was fair.

3.0-rc4      (plain)
cpu         Pkt run1        Pkt run2        Pkt run3
================================================
cpu0        21853354        21598183        22199900
cpu1          431058          473476          393159
cpu2          481975          477529          458466
cpu3        23261406        23412299        22894315
avg         11506948        11490372        11486460

3.0-rc4 with patch and default weight 64
cpu 	     Pkt run1        Pkt run2        Pkt run3
================================================
cpu0        13205312        13109359        13132333
cpu1        10189914        10159127        10122270
cpu2        10213871        10124367        10168722
cpu3        13165760        13164767        13096705
avg         11693714        11639405        11630008

As you can see the system is still not perfect but
is a lot better than what it was before...

At the moment we use the old backlog weight, weight_p
which is 64 packets. It seems to be reasonably fine
with that value.
The system could be made more fair if we reduce the
weight_p (as per my presentation), but we are going
to affect the shared backlog weight. Unless deemed
necessary, I think the default value is fine. If not
we could add yet another knob.

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-27 00:14:10 -07:00
David S. Miller 3019de124b net: Rework netdev_drivername() to avoid warning.
This interface uses a temporary buffer, but for no real reason.
And now can generate warnings like:

net/sched/sch_generic.c: In function dev_watchdog
net/sched/sch_generic.c:254:10: warning: unused variable drivername

Just return driver->name directly or "".

Reported-by: Connor Hansen <cmdkhh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-06 16:41:33 -07:00
Eric Dumazet 3137663dfb net: avoid synchronize_rcu() in dev_deactivate_many
dev_deactivate_many() issues one synchronize_rcu() call after qdiscs set
to noop_qdisc.

This call is here to make sure they are no outstanding qdisc-less
dev_queue_xmit calls before returning to caller.

But in dismantle phase, we dont have to wait, because we wont activate
again the device, and we are going to wait one rcu grace period later in
rollback_registered_many().

After this patch, device dismantle uses one synchronize_net() and one
rcu_barrier() call only, so we have a ~30% speedup and a smaller RTNL
latency.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>,
CC: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-22 21:01:20 -04:00
David S. Miller 0a0e9ae1bd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x.h
2011-03-03 21:27:42 -08:00
Eric Dumazet d276055c4e net_sched: reduce fifo qdisc size
Because of various alignements [SLUB / qdisc], we use 512 bytes of
memory for one {p|b}fifo qdisc, instead of 256 bytes on 64bit arches and
192 bytes on 32bit ones.

Move the "u32 limit" inside "struct Qdisc" (no impact on other qdiscs)

Change qdisc_alloc(), first trying a regular allocation before an
oversized one.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 11:10:02 -08:00
Eric W. Biederman 5f04d5068a net: Fix more stale on-stack list_head objects.
From: Eric W. Biederman <ebiederm@xmission.com>

In the beginning with batching unreg_list was a list that was used only
once in the lifetime of a network device (I think).  Now we have calls
using the unreg_list that can happen multiple times in the life of a
network device like dev_deactivate and dev_close that are also using the
unreg_list.  In addition in unregister_netdevice_queue we also do a
list_move because for devices like veth pairs it is possible that
unregister_netdevice_queue will be called multiple times.

So I think the change below to fix dev_deactivate which Eric D. missed
will fix this problem.  Now to go test that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-20 11:49:45 -08:00
Eric Dumazet 23624935e0 net_sched: TCQ_F_CAN_BYPASS generalization
Now qdisc stab is handled before TCQ_F_CAN_BYPASS test in
__dev_xmit_skb(), we can generalize TCQ_F_CAN_BYPASS to other qdiscs
than pfifo_fast : pfifo, bfifo, pfifo_head_drop and sfq

SFQ is special because it can have external classifiers, and in these
cases, we cannot bypass queue discipline (packet could be dropped by
classifier) without admin asking it, or further changes.

Its worth doing this, especially for SFQ, avoiding dirtying memory in
case no packets are already waiting in queue.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-21 16:26:09 -08:00
Eric Dumazet a2da570d62 net_sched: RCU conversion of stab
This patch converts stab qdisc management to RCU, so that we can perform
the qdisc_calculate_pkt_len() call before getting qdisc lock.

This shortens the lock's held time in __dev_xmit_skb().

This permits more qdiscs to get TCQ_F_CAN_BYPASS status, avoiding lot of
cache misses and so reducing latencies.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Jesper Dangaard Brouer <hawk@diku.dk>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Jamal Hadi Salim <hadi@cyberus.ca>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-20 16:59:32 -08:00
Eric Dumazet cc7ec456f8 net_sched: cleanups
Cleanup net/sched code to current CodingStyle and practices.

Reduce inline abuse

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 23:31:12 -08:00
John Fastabend b8970f0bfc net_sched: implement a root container qdisc sch_mqprio
This implements a mqprio queueing discipline that by default creates
a pfifo_fast qdisc per tx queue and provides the needed configuration
interface.

Using the mqprio qdisc the number of tcs currently in use along
with the range of queues alloted to each class can be configured. By
default skbs are mapped to traffic classes using the skb priority.
This mapping is configurable.

Configurable parameters,

struct tc_mqprio_qopt {
	__u8    num_tc;
	__u8    prio_tc_map[TC_BITMASK + 1];
	__u8    hw;
	__u16   count[TC_MAX_QUEUE];
	__u16   offset[TC_MAX_QUEUE];
};

Here the count/offset pairing give the queue alignment and the
prio_tc_map gives the mapping from skb->priority to tc.

The hw bit determines if the hardware should configure the count
and offset values. If the hardware bit is set then the operation
will fail if the hardware does not implement the ndo_setup_tc
operation. This is to avoid undetermined states where the hardware
may or may not control the queue mapping. Also minimal bounds
checking is done on the count/offset to verify a queue does not
exceed num_tx_queues and that queue ranges do not overlap. Otherwise
it is left to user policy or hardware configuration to create
useful mappings.

It is expected that hardware QOS schemes can be implemented by
creating appropriate mappings of queues in ndo_tc_setup().

One expected use case is drivers will use the ndo_setup_tc to map
queue ranges onto 802.1Q traffic classes. This provides a generic
mechanism to map network traffic onto these traffic classes and
removes the need for lower layer drivers to know specifics about
traffic types.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 23:31:11 -08:00
Octavian Purdila 443457242b net: factorize sync-rcu call in unregister_netdevice_many
Add dev_close_many and dev_deactivate_many to factorize another
sync-rcu operation on the netdevice unregister path.

$ modprobe dummy numdummies=10000
$ ip link set dev dummy* up
$ time rmmod dummy

Without the patch           With the patch

real    0m 24.63s           real    0m 5.15s
user    0m 0.00s            user    0m 0.00s
sys     0m 6.05s            sys     0m 5.14s

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 14:04:44 -08:00
Eric Dumazet f2cd2d3e9b net sched: use xps information for qdisc NUMA affinity
Allocate qdisc memory according to NUMA properties of cpus included in
xps map.

To be effective, qdisc should be (re)setup after changes
of /sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

I added a numa_node field in struct netdev_queue, containing NUMA node
if all cpus included in xps_cpus share same node, else -1.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-01 12:47:42 -08:00
Eric Dumazet 5a0d2268d2 net: add netif_tx_queue_frozen_or_stopped
When testing struct netdev_queue state against FROZEN bit, we also test
XOFF bit. We can test both bits at once and save some cycles.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28 10:47:18 -08:00
Changli Gao 3511c9132f net_sched: remove the unused parameter of qdisc_create_dflt()
The first parameter dev isn't in use in qdisc_create_dflt().

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 03:09:47 -07:00
Eric Dumazet 7b5edbc4cf net/sched: fix missing spinlock init
Under network load, doing :

tc qdisc del dev eth0 root

triggers :

[  167.193087] BUG: spinlock bad magic on CPU#3, udpflood/4928
[  167.193139]  lock: c15bc324, .magic: 00000000, .owner:
<none>/-1, .owner_cpu: -1
[  167.193193] Pid: 4928, comm: udpflood Not tainted
2.6.36-rc7-11417-g215340c-dirty #323
[  167.193245] Call Trace:
[  167.193292]  [<c13abaa0>] ? printk+0x18/0x20
[  167.193342]  [<c11afb53>] spin_bug+0xa3/0xf0
[  167.193389]  [<c11afcdd>] do_raw_spin_lock+0x7d/0x160
[  167.193440]  [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0
[  167.193496]  [<c107382b>] ? trace_hardirqs_on+0xb/0x10
[  167.193545]  [<c13ae99a>] _raw_spin_lock+0x3a/0x40
[  167.193593]  [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0
[  167.193641]  [<c1313d4e>] __dev_xmit_skb+0x27e/0x2b0

commit 79640a4ca6 (add additional lock to qdisc to increase
throughput) forgot to initialize  noop_qdisc and noqueue_qdisc busylock

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 03:09:40 -07:00
Eric Dumazet 24824a09e3 net: dynamic ingress_queue allocation
ingress being not used very much, and net_device->ingress_queue being
quite a big object (128 or 256 bytes), use a dynamic allocation if
needed (tc qdisc add dev eth0 ingress ...)

dev_ingress_queue(dev) helper should be used only with RTNL taken.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 00:23:44 -07:00
Eric Dumazet bfa5ae63b8 net: rename netdev rx_queue to ingress_queue
There is some confusion with rx_queue name after RPS, and net drivers
private rx_queue fields.

I suggest to rename "struct net_device"->rx_queue to ingress_queue.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-29 13:25:53 -07:00
Eric Dumazet d6d9ca0fec net: this_cpu_xxx conversions
Use modern this_cpu_xxx() api, saving few bytes on x86

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-19 15:12:51 -07:00
Eric Dumazet 79640a4ca6 net: add additional lock to qdisc to increase throughput
When many cpus compete for sending frames on a given qdisc, the qdisc
spinlock suffers from very high contention.

The cpu owning __QDISC_STATE_RUNNING bit has same priority to acquire
the lock, and cannot dequeue packets fast enough, since it must wait for
this lock for each dequeued packet.

One solution to this problem is to force all cpus spinning on a second
lock before trying to get the main lock, when/if they see
__QDISC_STATE_RUNNING already set.

The owning cpu then compete with at most one other cpu for the main
lock, allowing for higher dequeueing rate.

Based on a previous patch from Alexander Duyck. I added the heuristic to
avoid the atomic in fast path, and put the new lock far away from the
cache line used by the dequeue worker. Also try to release the busylock
lock as late as possible.

Tests with following script gave a boost from ~50.000 pps to ~600.000
pps on a dual quad core machine (E5450 @3.00GHz), tg3 driver.
(A single netperf flow can reach ~800.000 pps on this platform)

for j in `seq 0 3`; do
  for i in `seq 0 7`; do
    netperf -H 192.168.0.1 -t UDP_STREAM -l 60 -N -T $i -- -m 6 &
  done
done

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-02 05:09:29 -07:00
Eric Dumazet bc135b23d0 net: Define accessors to manipulate QDISC_STATE_RUNNING
Define three helpers to manipulate QDISC_STATE_RUNNIG flag, that a
second patch will move on another location.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-02 03:23:51 -07:00
Ian Campbell 06c4648d46 arp_notify: allow drivers to explicitly request a notification event.
Currently such notifications are only generated when the device comes up or the
address changes. However one use case for these notifications is to enable
faster network recovery after a virtual machine migration (by causing switches
to relearn their MAC tables). A migration appears to the network stack as a
temporary loss of carrier and therefore does not trigger either of the current
conditions. Rather than adding carrier up as a trigger (which can cause issues
when interfaces a flapping) simply add an interface which the driver can use
to explicitly trigger the notification.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-31 00:27:44 -07:00
Eric Dumazet 7fee226ad2 net: add a noref bit on skb dst
Use low order bit of skb->_skb_dst to tell dst is not refcounted.

Change _skb_dst to _skb_refdst to make sure all uses are catched.

skb_dst() returns the dst, regardless of noref bit set or not, but
with a lockdep check to make sure a noref dst is not given if current
user is not rcu protected.

New skb_dst_set_noref() helper to set an notrefcounted dst on a skb.
(with lockdep check)

skb_dst_drop() drops a reference only if skb dst was refcounted.

skb_dst_force() helper is used to force a refcount on dst, when skb
is queued and not anymore RCU protected.

Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if
!IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in
sock_queue_rcv_skb(), in __nf_queue().

Use skb_dst_force() in dev_requeue_skb().

Note: dst_use_noref() still dirties dst, we might transform it
later to do one dirtying per jiffies.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 17:18:50 -07:00
Changli Gao dee42870a4 net: fix softnet_stat
Per cpu variable softnet_data.total was shared between IRQ and SoftIRQ context
without any protection. And enqueue_to_backlog should update the netdev_rx_stat
of the target CPU.

This patch renames softnet_data.total to softnet_data.processed: the number of
packets processed in uppper levels(IP stacks).

softnet_stat data is moved into softnet_data.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
 include/linux/netdevice.h |   17 +++++++----------
 net/core/dev.c            |   26 ++++++++++++--------------
 net/sched/sch_generic.c   |    2 +-
 3 files changed, 20 insertions(+), 25 deletions(-)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-02 22:26:57 -07:00
David S. Miller 871039f02f Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/stmmac/stmmac_main.c
	drivers/net/wireless/wl12xx/wl1271_cmd.c
	drivers/net/wireless/wl12xx/wl1271_main.c
	drivers/net/wireless/wl12xx/wl1271_spi.c
	net/core/ethtool.c
	net/mac80211/scan.c
2010-04-11 14:53:53 -07:00
Eric Dumazet 5d944c640b gen_estimator: deadlock fix
One of my test machine got a deadlock during "tc" sessions,
adding/deleting classes & filters, using traffic estimators.

After some analysis, I believe we have a potential use after free case
in est_timer() :

spin_lock(e->stats_lock); << HERE >>
read_lock(&est_lock);
if (e->bstats == NULL)   << TEST >>
	goto skip;

Test is done a bit late, because after estimator is killed, and before
rcu grace period elapsed, we might already have freed/reuse memory where
e->stats_locks points to (some qdisc->q.lock)

A possible fix is to respect a rcu grace period at Qdisc dismantle time.

On 64bit, sizeof(struct Qdisc) is exactly 192 bytes. Adding 16 bytes to
it (for struct rcu_head) is a problem because it might change
performance, given QDISC_ALIGNTO is 32 bytes.

This is why I also change QDISC_ALIGNTO to 64 bytes, to satisfy most
current alignment requirements.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-01 18:38:48 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jarek Poplawski 9a1654ba0b net: Optimize hard_start_xmit() return checking
Recent changes in the TX error propagation require additional checking
and masking of values returned from hard_start_xmit(), mainly to
separate cases where skb was consumed. This aim can be simplified by
changing the order of NETDEV_TX and NET_XMIT codes, because the latter
are treated similarly to negative (ERRNO) values.

After this change much simpler dev_xmit_complete() is also used in
sch_direct_xmit(), so it is moved to netdevice.h.

Additionally NET_RX definitions in netdevice.h are moved up from
between TX codes to avoid confusion while reading the TX comment.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-15 22:08:33 -08:00
Patrick McHardy 572a9d7b6f net: allow to propagate errors through ->ndo_hard_start_xmit()
Currently the ->ndo_hard_start_xmit() callbacks are only permitted to return
one of the NETDEV_TX codes. This prevents any kind of error propagation for
virtual devices, like queue congestion of the underlying device in case of
layered devices, or unreachability in case of tunnels.

This patches changes the NET_XMIT codes to avoid clashes with the NETDEV_TX
codes and changes the two callers of dev_hard_start_xmit() to expect either
errno codes, NET_XMIT codes or NETDEV_TX codes as return value.

In case of qdisc_restart(), all non NETDEV_TX codes are mapped to NETDEV_TX_OK
since no error propagation is possible when using qdiscs. In case of
dev_queue_xmit(), the error is propagated upwards.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-13 14:07:32 -08:00
David S. Miller 6ec1c69a8f net_sched: add classful multiqueue dummy scheduler
This patch adds a classful dummy scheduler which can be used as root qdisc
for multiqueue devices and exposes each device queue as a child class.

This allows to address queues individually and graft them similar to regular
classes. Additionally it presents an accumulated view of the statistics of
all real root qdiscs in the dummy root.

Two new callbacks are added to the qdisc_ops and qdisc_class_ops:

- cl_ops->select_queue selects the tx queue number for new child classes.

- qdisc_ops->attach() overrides root qdisc device grafting to attach
  non-shared qdiscs to the queues.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:05 -07:00
Patrick McHardy 589983cd21 net_sched: move dev_graft_qdisc() to sch_generic.c
It will be used in a following patch by the multiqueue qdisc.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:05 -07:00
Patrick McHardy af356afa01 net_sched: reintroduce dev->qdisc for use by sch_api
Currently the multiqueue integration with the qdisc API suffers from
a few problems:

- with multiple queues, all root qdiscs use the same handle. This means
  they can't be exposed to userspace in a backwards compatible fashion.

- all API operations always refer to queue number 0. Newly created
  qdiscs are automatically shared between all queues, its not possible
  to address individual queues or restore multiqueue behaviour once a
  shared qdisc has been attached.

- Dumps only contain the root qdisc of queue 0, in case of non-shared
  qdiscs this means the statistics are incomplete.

This patch reintroduces dev->qdisc, which points to the (single) root qdisc
from userspace's point of view. Currently it either points to the first
(non-shared) default qdisc, or a qdisc shared between all queues. The
following patches will introduce a classful dummy qdisc, which will be used
as root qdisc and contain the per-queue qdiscs as children.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:03 -07:00
Krishna Kumar a453e0689a pkt_sched: Fix resource limiting in pfifo_fast
pfifo_fast_enqueue has this check:
        if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) {

which allows each band to enqueue upto tx_queue_len skbs for a
total of 3*tx_queue_len skbs. I am not sure if this was the
intention of limiting in qdisc.

Patch compiled and 32 simultaneous netperf testing ran fine. Also:
# tc -s qdisc show dev eth2
qdisc pfifo_fast 0: root bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
 Sent 16835026752 bytes 373116 pkt (dropped 0, overlimits 0 requeues 25) 
 rate 0bit 0pps backlog 0b 0p requeues 25 

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-30 22:20:28 -07:00