<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/netfilter/xt_RATEEST.c, branch v5.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500</title>
<updated>2019-06-19T15:09:55+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-06-04T08:11:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d2912cb15bdda8ba4a5dd73396ad62641af2f520'/>
<id>d2912cb15bdda8ba4a5dd73396ad62641af2f520</id>
<content type='text'>
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Enrico Weigelt &lt;info@metux.net&gt;
Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Enrico Weigelt &lt;info@metux.net&gt;
Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: xt_RATEEST: remove netns exit routine</title>
<updated>2018-11-13T08:57:29+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2018-10-18T15:27:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0fbcc5b568edab7d848b7c7fa66d44ffbd4133c0'/>
<id>0fbcc5b568edab7d848b7c7fa66d44ffbd4133c0</id>
<content type='text'>
xt_rateest_net_exit() was added to check whether rules are flushed
successfully. but -&gt;net_exit() callback is called earlier than
-&gt;destroy() callback.
So that -&gt;net_exit() callback can't check that.

test commands:
   %ip netns add vm1
   %ip netns exec vm1 iptables -t mangle -I PREROUTING -p udp \
	   --dport 1111 -j RATEEST --rateest-name ap \
	   --rateest-interval 250ms --rateest-ewma 0.5s
   %ip netns del vm1

splat looks like:
[  668.813518] WARNING: CPU: 0 PID: 87 at net/netfilter/xt_RATEEST.c:210 xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Modules linked in: xt_RATEEST xt_tcpudp iptable_mangle bpfilter ip_tables x_tables
[  668.813518] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc7+ #21
[  668.813518] Workqueue: netns cleanup_net
[  668.813518] RIP: 0010:xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Code: 00 48 8b 85 30 ff ff ff 4c 8b 23 80 38 00 0f 85 24 01 00 00 48 8b 85 30 ff ff ff 4d 85 e4 4c 89 a5 58 ff ff ff c6 00 f8 74 b2 &lt;0f&gt; 0b 48 83 c3 08 4c 39 f3 75 b0 48 b8 00 00 00 00 00 fc ff df 49
[  668.813518] RSP: 0018:ffff8801156c73f8 EFLAGS: 00010282
[  668.813518] RAX: ffffed0022ad8e85 RBX: ffff880118928e98 RCX: 5db8012a00000000
[  668.813518] RDX: ffff8801156c7428 RSI: 00000000cb1d185f RDI: ffff880115663b74
[  668.813518] RBP: ffff8801156c74d0 R08: ffff8801156633c0 R09: 1ffff100236440be
[  668.813518] R10: 0000000000000001 R11: ffffed002367d852 R12: ffff880115142b08
[  668.813518] R13: 1ffff10022ad8e81 R14: ffff880118928ea8 R15: dffffc0000000000
[  668.813518] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[  668.813518] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  668.813518] CR2: 0000563aa69f4f28 CR3: 0000000105a16000 CR4: 00000000001006f0
[  668.813518] Call Trace:
[  668.813518]  ? unregister_netdevice_many+0xe0/0xe0
[  668.813518]  ? xt_rateest_net_init+0x2c0/0x2c0 [xt_RATEEST]
[  668.813518]  ? default_device_exit+0x1ca/0x270
[  668.813518]  ? remove_proc_entry+0x1cd/0x390
[  668.813518]  ? dev_change_net_namespace+0xd00/0xd00
[  668.813518]  ? __init_waitqueue_head+0x130/0x130
[  668.813518]  ops_exit_list.isra.10+0x94/0x140
[  668.813518]  cleanup_net+0x45b/0x900
[  668.813518]  ? net_drop_ns+0x110/0x110
[  668.813518]  ? swapgs_restore_regs_and_return_to_usermode+0x3c/0x80
[  668.813518]  ? save_trace+0x300/0x300
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? process_one_work+0xb60/0x1de0
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? __lock_acquire+0x4500/0x4500
[  668.813518]  ? __lock_is_held+0xb4/0x140
[  668.813518]  process_one_work+0xc13/0x1de0
[  668.813518]  ? pwq_dec_nr_in_flight+0x3c0/0x3c0
[  668.813518]  ? set_load_weight+0x270/0x270
[ ... ]

Fixes: 3427b2ab63fa ("netfilter: make xt_rateest hash table per net")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
xt_rateest_net_exit() was added to check whether rules are flushed
successfully. but -&gt;net_exit() callback is called earlier than
-&gt;destroy() callback.
So that -&gt;net_exit() callback can't check that.

test commands:
   %ip netns add vm1
   %ip netns exec vm1 iptables -t mangle -I PREROUTING -p udp \
	   --dport 1111 -j RATEEST --rateest-name ap \
	   --rateest-interval 250ms --rateest-ewma 0.5s
   %ip netns del vm1

splat looks like:
[  668.813518] WARNING: CPU: 0 PID: 87 at net/netfilter/xt_RATEEST.c:210 xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Modules linked in: xt_RATEEST xt_tcpudp iptable_mangle bpfilter ip_tables x_tables
[  668.813518] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc7+ #21
[  668.813518] Workqueue: netns cleanup_net
[  668.813518] RIP: 0010:xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Code: 00 48 8b 85 30 ff ff ff 4c 8b 23 80 38 00 0f 85 24 01 00 00 48 8b 85 30 ff ff ff 4d 85 e4 4c 89 a5 58 ff ff ff c6 00 f8 74 b2 &lt;0f&gt; 0b 48 83 c3 08 4c 39 f3 75 b0 48 b8 00 00 00 00 00 fc ff df 49
[  668.813518] RSP: 0018:ffff8801156c73f8 EFLAGS: 00010282
[  668.813518] RAX: ffffed0022ad8e85 RBX: ffff880118928e98 RCX: 5db8012a00000000
[  668.813518] RDX: ffff8801156c7428 RSI: 00000000cb1d185f RDI: ffff880115663b74
[  668.813518] RBP: ffff8801156c74d0 R08: ffff8801156633c0 R09: 1ffff100236440be
[  668.813518] R10: 0000000000000001 R11: ffffed002367d852 R12: ffff880115142b08
[  668.813518] R13: 1ffff10022ad8e81 R14: ffff880118928ea8 R15: dffffc0000000000
[  668.813518] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[  668.813518] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  668.813518] CR2: 0000563aa69f4f28 CR3: 0000000105a16000 CR4: 00000000001006f0
[  668.813518] Call Trace:
[  668.813518]  ? unregister_netdevice_many+0xe0/0xe0
[  668.813518]  ? xt_rateest_net_init+0x2c0/0x2c0 [xt_RATEEST]
[  668.813518]  ? default_device_exit+0x1ca/0x270
[  668.813518]  ? remove_proc_entry+0x1cd/0x390
[  668.813518]  ? dev_change_net_namespace+0xd00/0xd00
[  668.813518]  ? __init_waitqueue_head+0x130/0x130
[  668.813518]  ops_exit_list.isra.10+0x94/0x140
[  668.813518]  cleanup_net+0x45b/0x900
[  668.813518]  ? net_drop_ns+0x110/0x110
[  668.813518]  ? swapgs_restore_regs_and_return_to_usermode+0x3c/0x80
[  668.813518]  ? save_trace+0x300/0x300
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? process_one_work+0xb60/0x1de0
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? __lock_acquire+0x4500/0x4500
[  668.813518]  ? __lock_is_held+0xb4/0x140
[  668.813518]  process_one_work+0xc13/0x1de0
[  668.813518]  ? pwq_dec_nr_in_flight+0x3c0/0x3c0
[  668.813518]  ? set_load_weight+0x270/0x270
[ ... ]

Fixes: 3427b2ab63fa ("netfilter: make xt_rateest hash table per net")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: make xt_rateest hash table per net</title>
<updated>2018-03-05T22:15:44+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2018-03-02T02:58:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3427b2ab63faccafe774ea997fc2da7faf690c5a'/>
<id>3427b2ab63faccafe774ea997fc2da7faf690c5a</id>
<content type='text'>
As suggested by Eric, we need to make the xt_rateest
hash table and its lock per netns to reduce lock
contentions.

Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As suggested by Eric, we need to make the xt_rateest
hash table and its lock per netns to reduce lock
contentions.

Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: xt_RATEEST: acquire xt_rateest_mutex for hash insert</title>
<updated>2018-02-06T23:58:57+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2018-02-05T22:41:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7dc68e98757a8eccf8ca7a53a29b896f1eef1f76'/>
<id>7dc68e98757a8eccf8ca7a53a29b896f1eef1f76</id>
<content type='text'>
rateest_hash is supposed to be protected by xt_rateest_mutex,
and, as suggested by Eric, lookup and insert should be atomic,
so we should acquire the xt_rateest_mutex once for both.

So introduce a non-locking helper for internal use and keep the
locking one for external.

Reported-by: &lt;syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com&gt;
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: Florian Westphal &lt;fw@strlen.de&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
rateest_hash is supposed to be protected by xt_rateest_mutex,
and, as suggested by Eric, lookup and insert should be atomic,
so we should acquire the xt_rateest_mutex once for both.

So introduce a non-locking helper for internal use and keep the
locking one for external.

Reported-by: &lt;syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com&gt;
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: Florian Westphal &lt;fw@strlen.de&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xtables: extend matches and targets with .usersize</title>
<updated>2017-01-09T16:24:55+00:00</updated>
<author>
<name>Willem de Bruijn</name>
<email>willemb@google.com</email>
</author>
<published>2017-01-02T22:19:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec23189049651b16dc2ffab35a4371dc1f491aca'/>
<id>ec23189049651b16dc2ffab35a4371dc1f491aca</id>
<content type='text'>
In matches and targets that define a kernel-only tail to their
xt_match and xt_target data structs, add a field .usersize that
specifies up to where data is to be shared with userspace.

Performed a search for comment "Used internally by the kernel" to find
relevant matches and targets. Manually inspected the structs to derive
a valid offsetof.

Signed-off-by: Willem de Bruijn &lt;willemb@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In matches and targets that define a kernel-only tail to their
xt_match and xt_target data structs, add a field .usersize that
specifies up to where data is to be shared with userspace.

Performed a search for comment "Used internally by the kernel" to find
relevant matches and targets. Manually inspected the structs to derive
a valid offsetof.

Signed-off-by: Willem de Bruijn &lt;willemb@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net_sched: gen_estimator: complete rewrite of rate estimators</title>
<updated>2016-12-05T20:21:59+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2016-12-04T17:48:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1c0d32fde5bdf1184bc274f864c09799278a1114'/>
<id>1c0d32fde5bdf1184bc274f864c09799278a1114</id>
<content type='text'>
1) Old code was hard to maintain, due to complex lock chains.
   (We probably will be able to remove some kfree_rcu() in callers)

2) Using a single timer to update all estimators does not scale.

3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity
   is not supposed to work well)

In this rewrite :

- I removed the RB tree that had to be scanned in
  gen_estimator_active(). qdisc dumps should be much faster.

- Each estimator has its own timer.

- Estimations are maintained in net_rate_estimator structure,
  instead of dirtying the qdisc. Minor, but part of the simplification.

- Reading the estimator uses RCU and a seqcount to provide proper
  support for 32bit kernels.

- We reduce memory need when estimators are not used, since
  we store a pointer, instead of the bytes/packets counters.

- xt_rateest_mt() no longer has to grab a spinlock.
  (In the future, xt_rateest_tg() could be switched to per cpu counters)

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
1) Old code was hard to maintain, due to complex lock chains.
   (We probably will be able to remove some kfree_rcu() in callers)

2) Using a single timer to update all estimators does not scale.

3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity
   is not supposed to work well)

In this rewrite :

- I removed the RB tree that had to be scanned in
  gen_estimator_active(). qdisc dumps should be much faster.

- Each estimator has its own timer.

- Estimations are maintained in net_rate_estimator structure,
  instead of dirtying the qdisc. Minor, but part of the simplification.

- Reading the estimator uses RCU and a seqcount to provide proper
  support for 32bit kernels.

- We reduce memory need when estimators are not used, since
  we store a pointer, instead of the bytes/packets counters.

- xt_rateest_mt() no longer has to grab a spinlock.
  (In the future, xt_rateest_tg() could be switched to per cpu counters)

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: Enhance the codes used to get random once</title>
<updated>2016-09-23T07:30:36+00:00</updated>
<author>
<name>Gao Feng</name>
<email>fgao@ikuai8.com</email>
</author>
<published>2016-09-18T02:52:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7bdc66242de7f9cbe8dbb01757042dd18744d800'/>
<id>7bdc66242de7f9cbe8dbb01757042dd18744d800</id>
<content type='text'>
There are some codes which are used to get one random once in netfilter.
We could use net_get_random_once to simplify these codes.

Signed-off-by: Gao Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are some codes which are used to get one random once in netfilter.
We could use net_get_random_once to simplify these codes.

Signed-off-by: Gao Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sched: do not acquire qdisc spinlock in qdisc/class stats dump</title>
<updated>2016-06-07T23:37:14+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2016-06-06T16:37:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=edb09eb17ed89eaa82a52dd306beac93e292b485'/>
<id>edb09eb17ed89eaa82a52dd306beac93e292b485</id>
<content type='text'>
Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host
agent [1] are problematic at scale :

For each qdisc/class found in the dump, we currently lock the root qdisc
spinlock in order to get stats. Sampling stats every 5 seconds from
thousands of HTB classes is a challenge when the root qdisc spinlock is
under high pressure. Not only the dumps take time, they also slow
down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases.

An audit of existing qdiscs showed that sch_fq_codel is the only qdisc
that might need the qdisc lock in fq_codel_dump_stats() and
fq_codel_dump_class_stats()

In v2 of this patch, I now use the Qdisc running seqcount to provide
consistent reads of packets/bytes counters, regardless of 32/64 bit arches.

I also changed rate estimators to use the same infrastructure
so that they no longer need to lock root qdisc lock.

[1]
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: Kevin Athey &lt;kda@google.com&gt;
Cc: Xiaotian Pei &lt;xiaotian@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host
agent [1] are problematic at scale :

For each qdisc/class found in the dump, we currently lock the root qdisc
spinlock in order to get stats. Sampling stats every 5 seconds from
thousands of HTB classes is a challenge when the root qdisc spinlock is
under high pressure. Not only the dumps take time, they also slow
down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases.

An audit of existing qdiscs showed that sch_fq_codel is the only qdisc
that might need the qdisc lock in fq_codel_dump_stats() and
fq_codel_dump_class_stats()

In v2 of this patch, I now use the Qdisc running seqcount to provide
consistent reads of packets/bytes counters, regardless of 32/64 bit arches.

I also changed rate estimators to use the same infrastructure
so that they no longer need to lock root qdisc lock.

[1]
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: Kevin Athey &lt;kda@google.com&gt;
Cc: Xiaotian Pei &lt;xiaotian@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sched: make bstats per cpu and estimator RCU safe</title>
<updated>2014-09-30T05:02:26+00:00</updated>
<author>
<name>John Fastabend</name>
<email>john.fastabend@gmail.com</email>
</author>
<published>2014-09-28T18:52:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa'/>
<id>22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa</id>
<content type='text'>
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 &lt;john.r.fastabend@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;john.r.fastabend@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hlist: drop the node parameter from iterators</title>
<updated>2013-02-28T03:10:24+00:00</updated>
<author>
<name>Sasha Levin</name>
<email>sasha.levin@oracle.com</email>
</author>
<published>2013-02-28T01:06:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b67bfe0d42cac56c512dd5da4b1b347a23f4b70a'/>
<id>b67bfe0d42cac56c512dd5da4b1b347a23f4b70a</id>
<content type='text'>
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj-&gt;member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    &lt;+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+&gt;

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Cc: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Cc: Gleb Natapov &lt;gleb@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj-&gt;member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    &lt;+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+&gt;

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Cc: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Cc: Gleb Natapov &lt;gleb@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
