Commit Graph

4597 Commits

Author SHA1 Message Date
David Miller
1026fec873 neigh: Create mechanism for generic neigh private areas.
The implementation private sits right after the primary_key memory.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-30 18:46:43 -05:00
Eric Dumazet
4d77d2b567 flow_dissector: use a 64bit load/store
Le lundi 28 novembre 2011 à 19:06 -0500, David Miller a écrit :
> From: Dimitris Michailidis <dm@chelsio.com>
> Date: Mon, 28 Nov 2011 08:25:39 -0800
>
> >> +bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys
> >> *flow)
> >> +{
> >> +	int poff, nhoff = skb_network_offset(skb);
> >> +	u8 ip_proto;
> >> +	u16 proto = skb->protocol;
> >
> > __be16 instead of u16 for proto?
>
> I'll take care of this when I apply these patches.

( CC trimmed )

Thanks David !

Here is a small patch to use one 64bit load/store on x86_64 instead of
two 32bit load/stores.

[PATCH net-next] flow_dissector: use a 64bit load/store

gcc compiler is smart enough to use a single load/store if we
memcpy(dptr, sptr, 8) on x86_64, regardless of
CONFIG_CC_OPTIMIZE_FOR_SIZE

In IP header, daddr immediately follows saddr, this wont change in the
future. We only need to make sure our flow_keys (src,dst) fields wont
break the rule.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 13:17:03 -05:00
Neal Cardwell
6b5a5c0dbb tcp: do not scale TSO segment size with reordering degree
Since 2005 (c1b4a7e695)
tcp_tso_should_defer has been using tcp_max_burst() as a target limit
for deciding how large to make outgoing TSO packets when not using
sysctl_tcp_tso_win_divisor. But since 2008
(dd9e0dda66) tcp_max_burst() returns the
reordering degree. We should not have tcp_tso_should_defer attempt to
build larger segments just because there is more reordering. This
commit splits the notion of deferral size used in TSO from the notion
of burst size used in cwnd moderation, and returns the TSO deferral
limit to its original value.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 00:29:41 -05:00
Ben Hutchings
c8f0b86996 dsa: Move all definitions needed by drivers into <net/dsa.h>
Any headers included by drivers should be under include/, and
any definitions they use are not really private to the core as
the name "dsa_priv.h" suggests.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 00:21:36 -05:00
David S. Miller
8317e2047e Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2011-11-28 19:21:10 -05:00
Eric Dumazet
0744dd00c1 net: introduce skb_flow_dissect()
We use at least two flow dissectors in network stack, with known
limitations and code duplication.

Introduce skb_flow_dissect() to factorize this, highly inspired from
existing dissector from __skb_get_rxhash()

Note : We extensively use skb_header_pointer(), this permits us to not
touch skb at all.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28 19:09:07 -05:00
John W. Linville
39338b5638 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2011-11-28 14:11:18 -05:00
Ben Hutchings
cf50dcc24f dsa: Change dsa_uses_{dsa, trailer}_tags() into inline functions
eth_type_trans() will use these functions if DSA is enabled, which
blocks building DSA as a module.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 14:48:14 -05:00
David S. Miller
6dec4ac4ee Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv4/inet_diag.c
2011-11-26 14:47:03 -05:00
Steffen Klassert
b8400f3718 route: struct rtable can be const in rt_is_input_route and rt_is_output_route
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 14:29:51 -05:00
Steffen Klassert
618f9bc74a net: Move mtu handling down to the protocol depended handlers
We move all mtu handling from dst_mtu() down to the protocol
layer. So each protocol can implement the mtu handling in
a different manner.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 14:29:51 -05:00
Steffen Klassert
ebb762f27f net: Rename the dst_opt default_mtu method to mtu
We plan to invoke the dst_opt->default_mtu() method unconditioally
from dst_mtu(). So rename the method to dst_opt->mtu() to match
the name with the new meaning.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26 14:29:50 -05:00
Li Wei
ac8a48106b ipv4: Save nexthop address of LSRR/SSRR option to IPCB.
We can not update iph->daddr in ip_options_rcv_srr(), It is too early.
When some exception ocurred later (eg. in ip_forward() when goto
sr_failed) we need the ip header be identical to the original one as
ICMP need it.

Add a field 'nexthop' in struct ip_options to save nexthop of LSRR
or SSRR option.

Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-23 19:19:32 -05:00
Neil Horman
8c2152286a netprio_cgroup: Fix build break
I broke the build with the addition of netprio_cgroups if CONFIG_CGROUPS=n.
This patch corrects it by moving the offending struct into an ifdef
CONFIG_CGROUPS block.  Also clean up a few needless defines and inline functions
that don't get called if CONFIG_CGROUPS isn't defined while Im at it.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-23 15:52:58 -05:00
Alexey Dobriyan
4e3fd7a06d net: remove ipv6_addr_copy()
C assignment can handle struct in6_addr copying.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-22 16:43:32 -05:00
Alexey Dobriyan
26bff940dd xfrm: optimize ipv4 selector matching
Current addr_match() is errh, under-optimized.

Compiler doesn't know that memcmp() branch doesn't trigger for IPv4.
Also, pass addresses by value -- they fit into register.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-22 15:27:18 -05:00
Neil Horman
5bc1421e34 net: add network priority cgroup infrastructure (v4)
This patch adds in the infrastructure code to create the network priority
cgroup.  The cgroup, in addition to the standard processes file creates two
control files:

1) prioidx - This is a read-only file that exports the index of this cgroup.
This is a value that is both arbitrary and unique to a cgroup in this subsystem,
and is used to index the per-device priority map

2) priomap - This is a writeable file.  On read it reports a table of 2-tuples
<name:priority> where name is the name of a network interface and priority is
indicates the priority assigned to frames egresessing on the named interface and
originating from a pid in this cgroup

This cgroup allows for skb priority to be set prior to a root qdisc getting
selected. This is benenficial for DCB enabled systems, in that it allows for any
application to use dcb configured priorities so without application modification

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
CC: Robert Love <robert.w.love@intel.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-22 15:22:23 -05:00
John W. Linville
515db09338 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
Conflicts:
	drivers/net/wireless/iwlegacy/iwl-debugfs.c
	drivers/net/wireless/iwlegacy/iwl-rx.c
	drivers/net/wireless/iwlegacy/iwl-scan.c
	drivers/net/wireless/iwlegacy/iwl-tx.c
	include/net/bluetooth/bluetooth.h
2011-11-22 14:05:46 -05:00
Ben Greear
7e7c8926b2 wireless: Support ht-capabilities over-rides.
This allows users to disable features such as HT, HT40,
and to modify the MCS, AMPDU, and AMSDU settings for
drivers that support it.

The MCS, AMPDU, and AMSDU features that may be disabled are
are reported in the phy-info netlink message as a mask.

Attemping to disable features that are not supported will
take no affect, but will not return errors.  This is to aid
backwards compatibility in user-space apps that may not be
clever enough to deal with parsing the the capabilities mask.

This patch only enables the infrastructure.  An additional
patch will enable the feature in mac80211.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:22:06 -05:00
Johannes Berg
dd76986b0e cfg80211/mac80211: Revert "move information element parsing logic to cfg80211"
No other driver ever ended up using this, and
the commit forgot to move the prototype so no
driver could have used it. Revert it, if any
driver shows up and needs it it can be moved
again, but until then it's more efficient to
have it in mac80211 where the only user is.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:20:49 -05:00
Johannes Berg
7c4ef7122c cfg80211: add flags for off-channel capabilities
Currently mac80211 implements these for all devices,
but given restrictions of some devices that isn't
really true, so prepare for being able to remove the
capability for some mac80211 devices.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:20:49 -05:00
Johannes Berg
11127e9121 mac80211: transmit fragment list to drivers
Drivers can usually handle fragmented packets
much easier when they get the entire list of
fragments at once. The only thing they need to
do is keep enough space on the queues for up
to ten fragments of a single MSDU.

This allows them to implement this with a new
operation tx_frags.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:20:43 -05:00
Luis R. Rodriguez
b68e6b3b33 cfg80211: pass DFS region to drivers through reg_notifier()
This grants drivers access to the DFS region that a
regulatory domain belongs to.

Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:20:41 -05:00
Luis R. Rodriguez
8b60b07805 cfg80211: process regulatory DFS region for countries
The wireless-regdb now has support for mapping a country to
one DFS region. CRDA sends this to us now so process it
so we can provide that hint to drivers. This will later be
used by code for processing DFS in a way that meets the
criteria for the DFS region the country belongs to.

Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:20:41 -05:00
Ilan Elias
ccb290fccc NFC: Fix indentation in nci.h file
Fix indentation in nci.h file.

Signed-off-by: Ilan Elias <ilane@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-17 15:43:55 -05:00
John W. Linville
e11c259f74 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
Conflicts:
	include/net/bluetooth/bluetooth.h
2011-11-17 13:11:43 -05:00
Michał Mirosław
c8f44affb7 net: introduce and use netdev_features_t for device features sets
v2:	add couple missing conversions in drivers
	split unexporting netdev_fix_features()
	implemented %pNF
	convert sock::sk_route_(no?)caps

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-16 17:43:10 -05:00
Eric Dumazet
8b5c171bb3 neigh: new unresolved queue limits
Le mercredi 09 novembre 2011 à 16:21 -0500, David Miller a écrit :
> From: David Miller <davem@davemloft.net>
> Date: Wed, 09 Nov 2011 16:16:44 -0500 (EST)
>
> > From: Eric Dumazet <eric.dumazet@gmail.com>
> > Date: Wed, 09 Nov 2011 12:14:09 +0100
> >
> >> unres_qlen is the number of frames we are able to queue per unresolved
> >> neighbour. Its default value (3) was never changed and is responsible
> >> for strange drops, especially if IP fragments are used, or multiple
> >> sessions start in parallel. Even a single tcp flow can hit this limit.
> >  ...
> >
> > Ok, I've applied this, let's see what happens :-)
>
> Early answer, build fails.
>
> Please test build this patch with DECNET enabled and resubmit.  The
> decnet neigh layer still refers to the removed ->queue_len member.
>
> Thanks.

Ouch, this was fixed on one machine yesterday, but not the other one I
used this morning, sorry.

[PATCH V5 net-next] neigh: new unresolved queue limits

unres_qlen is the number of frames we are able to queue per unresolved
neighbour. Its default value (3) was never changed and is responsible
for strange drops, especially if IP fragments are used, or multiple
sessions start in parallel. Even a single tcp flow can hit this limit.

$ arp -d 192.168.20.108 ; ping -c 2 -s 8000 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 8000(8028) bytes of data.
8008 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.322 ms

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-14 00:47:54 -05:00
alex.bluesman.smirnov@gmail.com
719269afbc 6LoWPAN: add fragmentation support
This patch adds support for frame fragmentation.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-14 00:19:42 -05:00
Eric Dumazet
2a24444f8f ipv6: reduce percpu needs for icmpv6msg mibs
Reading /proc/net/snmp6 on a machine with a lot of cpus is very
expensive (can be ~88000 us).

This is because ICMPV6MSG MIB uses 4096 bytes per cpu, and folding
values for all possible cpus can read 16 Mbytes of memory (32MBytes on
non x86 arches)

ICMP messages are not considered as fast path on a typical server, and
eventually few cpus handle them anyway. We can afford an atomic
operation instead of using percpu data.

This saves 4096 bytes per cpu and per network namespace.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-14 00:12:26 -05:00
Arik Nemtsov
0294582126 mac80211: Save probe response data for bss
Allow setting a probe response template for an interface operating in
AP mode. Low level drivers are notified about changes in the probe
response template and are able to retrieve a copy of the current probe
response. This data can, for example, be uploaded to hardware as a
template.

Signed-off-by: Guy Eilam <guy@wizery.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:51 -05:00
Arik Nemtsov
00f740e1a3 nl80211: Pass probe response data to drivers
Pass probe-response data from usermode via beacon parameters.

Signed-off-by: Guy Eilam <guy@wizery.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:51 -05:00
Arik Nemtsov
87bbbe22f8 nl80211: Add probe response offload attribute
Notify user-space about probe-response offloading support in the driver.

A wiphy flag is used to indicate support and a bitmap of protocols
determines which protocols are supported.

Signed-off-by: Guy Eilam <guy@wizery.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:51 -05:00
Johannes Berg
776d68f863 wireless: move ieee80211chan2mhz macro
The macro is only used in ipw2200 and we certainly
don't want to encourage its use, so move it out of
the radiotap header file and into the driver.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:50 -05:00
Ilan Elias
db98c829b7 NFC: Check if NCI data flow control is used
Check if NCI data flow control is used in nci_tx_work.

Signed-off-by: Ilan Elias <ilane@ti.com>
Acked-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:50 -05:00
Ilan Elias
ee4c64fb98 NFC: Removal of unused operations for NCI spec 1.0 d18
Remove unused NCI operations, e.g. create static rf connection.

Signed-off-by: Ilan Elias <ilane@ti.com>
Acked-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:50 -05:00
Ilan Elias
e8c0dacd98 NFC: Update names and structs to NCI spec 1.0 d18
Addition, deletion and modification of NCI constants.
Changes in NCI commands, responses and notifications structures.

Signed-off-by: Ilan Elias <ilane@ti.com>
Acked-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:50 -05:00
Johannes Berg
e999882a05 mac80211/cfg80211: report monitor channel in wireless extensions
Just add API to get the channel & report it. Trivial really.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11 12:32:50 -05:00
Eric Dumazet
d826eb14ec ipv4: PKTINFO doesnt need dst reference
Le lundi 07 novembre 2011 à 15:33 +0100, Eric Dumazet a écrit :

> At least, in recent kernels we dont change dst->refcnt in forwarding
> patch (usinf NOREF skb->dst)
>
> One particular point is the atomic_inc(dst->refcnt) we have to perform
> when queuing an UDP packet if socket asked PKTINFO stuff (for example a
> typical DNS server has to setup this option)
>
> I have one patch somewhere that stores the information in skb->cb[] and
> avoid the atomic_{inc|dec}(dst->refcnt).
>

OK I found it, I did some extra tests and believe its ready.

[PATCH net-next] ipv4: IP_PKTINFO doesnt need dst reference

When a socket uses IP_PKTINFO notifications, we currently force a dst
reference for each received skb. Reader has to access dst to get needed
information (rt_iif & rt_spec_dst) and must release dst reference.

We also forced a dst reference if skb was put in socket backlog, even
without IP_PKTINFO handling. This happens under stress/load.

We can instead store the needed information in skb->cb[], so that only
softirq handler really access dst, improving cache hit ratios.

This removes two atomic operations per packet, and false sharing as
well.

On a benchmark using a mono threaded receiver (doing only recvmsg()
calls), I can reach 720.000 pps instead of 570.000 pps.

IP_PKTINFO is typically used by DNS servers, and any multihomed aware
UDP application.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-09 16:36:27 -05:00
David S. Miller
3b971a7ceb Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2011-11-09 16:22:15 -05:00
Johannes Berg
a729cff8ad mac80211: implement wifi TX status
Implement the socket wifi TX status error
queue reflection in mac80211.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:14:09 -05:00
Johannes Berg
1f074bd8eb nl80211: advertise socket TX status capability
The new wifi socket TX capability should be
supported by wifi drivers, let them advertise
whether they do or not.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:14:08 -05:00
Johannes Berg
e247bd9068 cfg80211/mac80211: allow management TX to not wait for ACK
For probe responses it can be useful to not wait for ACK to
avoid retransmissions if the station that sent the probe is
already on the next channel, so allow userspace to request
not caring about the ACK with a new nl80211 flag.

Since mac80211 needs to be updated for the new function
prototype anyway implement it right away -- it's just a
few lines of code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:13:54 -05:00
Johannes Berg
b92ab5d86d cfg80211: add event for unexpected 4addr frames
The frames are used by AP/STA WDS mode, and hostapd
needs to know when such a frame was received to set
up the VLAN appropriately to allow using it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:13:52 -05:00
Johannes Berg
5e760230e4 cfg80211: allow registering to beacons
Add the ability to register to received beacon frames
to allow implementing OLBC logic in userspace. The
registration is per wiphy since there's no point in
receiving the same frame multiple times.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:13:51 -05:00
Johannes Berg
7f6cf311a5 nl80211: add API to probe a client
When the AP SME in hostapd is used it wants to
probe the clients when they have been idle for
some time. Add explicit API to support this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:12:39 -05:00
Johannes Berg
562a74803f nl80211: advertise device AP SME
Add the ability to advertise that the device
contains the AP SME and what features it can
support. There are currently no features in
the bitmap -- probe response offload will be
advertised by a few patches Arik is working
on now (who took over from Guy Eilam) and a
device with AP SME will typically implement
and require response offload.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:12:38 -05:00
Johannes Berg
28946da763 nl80211: allow subscribing to unexpected class3 frames
To implement AP mode without monitor interfaces we
need to be able to send a deauth to stations that
send frames without being associated. Enable this
by adding a new nl80211 event for such frames that
an application can subscribe to.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:05:49 -05:00
Johannes Berg
6096de7fd4 mac80211: add helper to free TX skb
Drivers that need to drop a frame before it
can be transmitted will usually simply free
that frame. This is currently fine, but in
the future it'll be needed to tell mac80211
about this case, so add a new routine that
frees a TX skb.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-09 16:05:48 -05:00
Eric Dumazet
acb32ba3de ipv4: reduce percpu needs for icmpmsg mibs
Reading /proc/net/snmp on a machine with a lot of cpus is very expensive
(can be ~88000 us).

This is because ICMPMSG MIB uses 4096 bytes per cpu, and folding values
for all possible cpus can read 16 Mbytes of memory.

ICMP messages are not considered as fast path on a typical server, and
eventually few cpus handle them anyway. We can afford an atomic
operation instead of using percpu data.

This saves 4096 bytes per cpu and per network namespace.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-09 16:04:20 -05:00