Now that there is a one-to-one correspondance between neighbour
and hh_cache entries, we no longer need:
1) dynamic allocation
2) attachment to dst->hh
3) refcounting
Initialization of the hh_cache entry is indicated by hh_len
being non-zero, and such initialization is always done with
the neighbour's lock held as a writer.
Signed-off-by: David S. Miller <davem@davemloft.net>
And mask the hash function result by simply shifting
down the "->hash_shift" most significant bits.
Currently which bits we use is arbitrary since jhash
produces entropy evenly across the whole hash function
result.
But soon we'll be using universal hashing functions,
and in those cases more entropy exists in the higher
bits than the lower bits, because they use multiplies.
Signed-off-by: David S. Miller <davem@davemloft.net>
jiffies is defined as "volatile".
extern unsigned long volatile __jiffy_data jiffies;
ACCESS_ONCE() uses "volatile".
As a result, some compilers warn duplicate `volatile' for ACCESS_ONCE(jiffies).
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is important to move nud_state outside of the often modified cache
line (because of refcnt), to reduce false sharing in neigh_event_send()
This is a followup of commit 0ed8ddf404 (neigh: Protect neigh->ha[]
with a seqlock)
This gives a 7% speedup on routing test with IP route cache disabled.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Le mardi 12 octobre 2010 à 00:02 +0200, Eric Dumazet a écrit :
> Here is the followup patch.
>
> Thanks !
>
Oops, this was an old version, the up2date ones also took care of "used"
field.
I guess its time for a sleep, sorry again.
[PATCH net-next V2] neigh: reorder struct neighbour fields
(refcnt) and (ha_lock, ha, used, dev, output, ops, primary_key) should
be placed on a separate cache lines.
refcnt can be often written, while other fields are mostly read.
This gave me good result on stress test :
before:
real 0m45.570s
user 0m15.525s
sys 9m56.669s
After:
real 0m41.841s
user 0m15.261s
sys 8m45.949s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a seqlock in struct neighbour to protect neigh->ha[], and avoid
dirtying neighbour in stress situation (many different flows / dsts)
Dirtying takes place because of read_lock(&n->lock) and n->used writes.
Switching to a seqlock, and writing n->used only on jiffies changes
permits less dirtying.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the second step for neighbour RCU conversion.
(first was commit d6bf7817 : RCU conversion of neigh hash table)
neigh_lookup() becomes lockless, but still take a reference on found
neighbour. (no more read_lock()/read_unlock() on tbl->lock)
struct neighbour gets an additional rcu_head field and is freed after an
RCU grace period.
Future work would need to eventually not take a reference on neighbour
for temporary dst (DST_NOCACHE), but this would need dst->_neighbour to
use a noref bit like we did for skb->_dst.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David
This is the first step for RCU conversion of neigh code.
Next patches will convert hash_buckets[] and "struct neighbour" to RCU
protected objects.
Thanks
[PATCH net-next] net neigh: RCU conversion of neigh hash table
Instead of storing hash_buckets, hash_mask and hash_rnd in "struct
neigh_table", a new structure is defined :
struct neigh_hash_table {
struct neighbour **hash_buckets;
unsigned int hash_mask;
__u32 hash_rnd;
struct rcu_head rcu;
};
And "struct neigh_table" has an RCU protected pointer to such a
neigh_hash_table.
This means the signature of (*hash)() function changed: We need to add a
third parameter with the actual hash_rnd value, since this is not
anymore a neigh_table field.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On 64bit arches, there are two 32bit holes that we can remove.
sizeof(struct neighbour) shrinks from 0xf8 to 0xf0 bytes
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- fix IP DNAT on vlan- or pppoe-encapsulated traffic: The functions
neigh_hh_output() or dst->neighbour->output() overwrite the complete
Ethernet header, although we only need the destination MAC address.
For encapsulated packets, they ended up overwriting the encapsulating
header. The new code copies the Ethernet source MAC address and
protocol number before calling dst->neighbour->output(). The Ethernet
source MAC and protocol number are copied back in place in
br_nf_pre_routing_finish_bridge_slow(). This also makes the IP DNAT
more transparent because in the old scheme the source MAC of the
bridge was copied into the source address in the Ethernet header. We
also let skb->protocol equal ETH_P_IP resp. ETH_P_IPV6 during the
execution of the PF_INET resp. PF_INET6 hooks.
- Speed up IP DNAT by calling neigh_hh_bridge() instead of
neigh_hh_output(): if dst->hh is available, we already know the MAC
address so we can just copy it.
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Add __percpu sparse annotations to net.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
The macro and type tricks around snmp stats make things a bit
interesting. DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly. All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Stop computing the number of neighbour table settings we have by
counting the number of binary sysctls. This behaviour was silly
and meant that we could not add another neighbour table setting
without also adding another binary sysctl.
Don't pass the binary sysctl path for neighour table entries
into neigh_sysctl_register. These parameters are no longer
used and so are just dead code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits)
mac80211: fix reorder buffer release
iwmc3200wifi: Enable wimax core through module parameter
iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter
iwmc3200wifi: Coex table command does not expect a response
iwmc3200wifi: Update wiwi priority table
iwlwifi: driver version track kernel version
iwlwifi: indicate uCode type when fail dump error/event log
iwl3945: remove duplicated event logging code
b43: fix two warnings
ipw2100: fix rebooting hang with driver loaded
cfg80211: indent regulatory messages with spaces
iwmc3200wifi: fix NULL pointer dereference in pmkid update
mac80211: Fix TX status reporting for injected data frames
ath9k: enable 2GHz band only if the device supports it
airo: Fix integer overflow warning
rt2x00: Fix padding bug on L2PAD devices.
WE: Fix set events not propagated
b43legacy: avoid PPC fault during resume
b43: avoid PPC fault during resume
tcp: fix a timewait refcnt race
...
Fix up conflicts due to sysctl cleanups (dead sysctl_check code and
CTL_UNNUMBERED removed) in
kernel/sysctl_check.c
net/ipv4/sysctl_net_ipv4.c
net/ipv6/addrconf.c
net/sctp/sysctl.c
Now that sys_sysctl is a compatiblity wrapper around /proc/sys
all sysctl strategy routines, and all ctl_name and strategy
entries in the sysctl tables are unused, and can be
revmoed.
In addition neigh_sysctl_register has been modified to no longer
take a strategy argument and it's callers have been modified not
to pass one.
Cc: "David Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These tables are never modified at runtime. Move to read-only
section.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current neigh_periodic_timer() function is fired by timer IRQ, and
scans one hash bucket each round (very litle work in fact)
As we are supposed to scan whole hash table in 15 seconds, this means
neigh_periodic_timer() can be fired very often. (depending on the number
of concurrent hash entries we stored in this table)
Converting this to a workqueue permits scanning whole table, minimizing
icache pollution, and firing this work every 15 seconds, independantly
of hash table size.
This 15 seconds delay is not a hard number, as work is a deferrable one.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using read_pnet() and write_pnet() in neighbour code ease the reading
of code.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
->pde isn't actually needed, since name is stashed in ->id.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
in __neigh_event_send, if we have a neighbour entry which is in
NUD_INCOMPLETE state, we enqueue any outbound frames to that neighbour
to the neighbours arp_queue, which is default capped to a length of 3
skbs. If that queue exceeds its set length, it will drop an skb on
the queue to enqueue the newly arrived skb. This results in a drop
for which we have no statistics incremented. This patch adds an
unresolved_discards stat to /proc/net/stat/ndisc_cache to track these
lost frames.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce neigh_parms/pneigh_entry inlines: neigh_parms_net(), pneigh_net().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Proxy neighbors do not have any reference counting, so any caller
of pneigh_lookup (unless it's a netlink triggered add/del routine)
should _not_ perform any actions on the found proxy entry.
There's one exception from this rule - the ipv6's ndisc_recv_ns()
uses found entry to check the flags for NTF_ROUTER.
This creates a race between the ndisc and pneigh_delete - after
the pneigh is returned to the caller, the nd_tbl.lock is dropped
and the deleting procedure may proceed.
One of the fixes would be to add a reference counting, but this
problem exists for ndisc only. Besides such a patch would be too
big for -rc4.
So I propose to introduce a __pneigh_lookup() which is supposed
to be called with the lock held and use it in ndisc code to check
the flags on alive pneigh entry.
Changes from v2:
As David noticed, Exported the __pneigh_lookup() to ipv6 module.
The checkpatch generates a warning on it, since the EXPORT_SYMBOL
does not follow the symbol itself, but in this file all the
exports come at the end, so I decided no to break this harmony.
Changes from v1:
Fixed comments from YOSHIFUJI - indentation of prototype in header
and the pndisc_check_router() name - and a compilation fix, pointed
by Daniel - the is_routed was (falsely) considered as uninitialized
by gcc.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
neigh_is_connected() is not popular at all, and the only user
drivers/net/cxgb3/l2t.c:t3_l2t_update() also have raw (expanded) expression.
Let's expand it and remove the inline function.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Make them static.
[ Moved the inline before, instead of after, call sites. -DaveM ]
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When I studied the neighbor code I puzzled over what the NUD can mean
for quite a long time.
Finally I asked Alexey and he said that this was smth like "neighbor
unreachability detection".
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
seq_open_net requires that first field of the seq->private data to be
struct seq_net_private. In reality this is a single pointer to a
struct net for now. The patch makes code consistent.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I'm actually surprised at how much was involved. At first glance it
appears that the neighbour table data structures are already split by
network device so all that should be needed is to modify the user
interface commands to filter the set of neighbours by the network
namespace of their devices.
However a couple things turned up while I was reading through the
code. The proxy neighbour table allows entries with no network
device, and the neighbour parms are per network device (except for the
defaults) so they now need a per network namespace default.
So I updated the two structures (which surprised me) with their very
own network namespace parameter. Updated the relevant lookup and
destroy routines with a network namespace parameter and modified the
code that interacts with users to filter out neighbour table entries
for devices of other namespaces.
I'm a little concerned that we can modify and display the global table
configuration and from all network namespaces. But this appears good
enough for now.
I keep thinking modifying the neighbour table to have per network
namespace instances of each table type would should be cleaner. The
hash table is already dynamically sized so there are it is not a
limiter. The default parameter would be straight forward to take care
of. However when I look at the how the network table is built and
used I still find some assumptions that there is only a single
neighbour table for each type of table in the kernel. The netlink
operations, neigh_seq_start, the non-core network users that call
neigh_lookup. So while it might be doable it would require more
refactoring than my current approach of just doing a little extra
filtering in the code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
->neigh_destructor() is killed (not used), replaced with
->neigh_cleanup(), which is called when neighbor entry goes to dead
state. At this point everything is still valid: neigh->dev,
neigh->parms etc.
The device should guarantee that dead neighbor entries (neigh->dead !=
0) do not get private part initialized, otherwise nobody will cleanup
it.
I think this is enough for ipoib which is the only user of this thing.
Initialization private part of neighbor entries happens in ipib
start_xmit routine, which is not reached when device is down. But it
would be better to add explicit test for neigh->dead in any case.
Signed-off-by: David S. Miller <davem@davemloft.net>
The hard header cache is in the main output path, so using
seqlock instead of reader/writer lock should reduce overhead.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We have sent NA with router flag from the node-wide forwarding
configuration. This is not appropriate for proxy NA, and it should be
set according to each proxy entry's configuration.
This is used by Mobile IPv6 home agent to support physical home link
in acting as a proxy router for mobile node which is not a router,
for example.
Based on MIPL2 kernel patch.
Signed-off-by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Rather than opencoding the mask, it looks better to use ALIGN()
macro from kernel.h.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Moves netlink neighbour bits to linux/neighbour.h. Also
moves bits to be exported to userspace from net/neighbour.h
to linux/neighbour.h and removes __KERNEL__ guards, userspace
is not supposed to be using it.
rtnetlink_rcv_msg() is not longer required to parse attributes
for the neighbour layer, remove dependency on obsolete and
buggy rta_buf.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The classical IP over ATM code maintains its own IPv4 <-> <ATM stuff>
ARP table, using the standard neighbour-table code. The
neigh_table_init function adds this neighbour table to a linked list
of all neighbor tables which is used by the functions neigh_delete()
neigh_add() and neightbl_set(), all called by the netlink code.
Once the ATM neighbour table is added to the list, there are two
tables with family == AF_INET there, and ARP entries sent via netlink
go into the first table with matching family. This is indeterminate
and often wrong.
To see the bug, on a kernel with CLIP enabled, create a standard IPv4
ARP entry by pinging an unused address on a local subnet. Then attempt
to complete that entry by doing
ip neigh replace <ip address> lladdr <some mac address> nud reachable
Looking at the ARP tables by using
ip neigh show
will reveal two ARP entries for the same address. One of these can be
found in /proc/net/arp, and the other in /proc/net/atm/arp.
This patch adds a new function, neigh_table_init_no_netlink() which
does everything the neigh_table_init() does, except add the table to
the netlink all-arp-tables chain. In addition neigh_table_init() has a
check that all tables on the chain have a distinct address family.
The init call in clip.c is changed to call
neigh_table_init_no_netlink().
Since ATM ARP tables are rather more complicated than can currently be
handled by the available rtattrs in the netlink protocol, no
functionality is lost by this patch, and non-ATM ARP manipulation via
netlink is rescued. A more complete solution would involve a rtattr
for ATM ARP entries and some way for the netlink code to give
neigh_add and friends more information than just address family with
which to find the correct ARP table.
[ I've changed the assertion checking in neigh_table_init() to not
use BUG_ON() while holding neigh_tbl_lock. Instead we remember that
we found an existing tbl with the same family, and after dropping
the lock we'll give a diagnostic kernel log message and a stack dump.
-DaveM ]
Signed-off-by: Simon Kelley <simon@thekelleys.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct neigh_ops currently has a destructor field, which no in-kernel
drivers outside of infiniband use. The infiniband/ulp/ipoib in-tree
driver stashes some info in the neighbour structure (the results of
the second-stage lookup from ARP results to real link-level path), and
it uses neigh->ops->destructor to get a callback so it can clean up
this extra info when a neighbour is freed. We've run into problems
with this: since the destructor is in an ops field that is shared
between neighbours that may belong to different net devices, there's
no way to set/clear it safely.
The following patch moves this field to neigh_parms where it can be
safely set, together with its twin neigh_setup. Two additional
patches in the patch series update ipoib to use this new interface.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To help in reducing the number of include dependencies, several files were
touched as they were getting needed headers indirectly for stuff they use.
Thanks also to Alan Menegotto for pointing out that net/dccp/proto.c had
linux/dccp.h include twice.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To retrieve the neighbour tables send RTM_GETNEIGHTBL with the
NLM_F_DUMP flag set. Every neighbour table configuration is
spread over multiple messages to avoid running into message
size limits on systems with many interfaces. The first message
in the sequence transports all not device specific data such as
statistics, configuration, and the default parameter set.
This message is followed by 0..n messages carrying device
specific parameter sets.
Although the ordering should be sufficient, NDTA_NAME can be
used to identify sequences. The initial message can be identified
by checking for NDTA_CONFIG. The device specific messages do
not contain this TLV but have NDTPA_IFINDEX set to the
corresponding interface index.
To change neighbour table attributes, send RTM_SETNEIGHTBL
with NDTA_NAME set. Changeable attribute include NDTA_THRESH[1-3],
NDTA_GC_INTERVAL, and all TLVs in NDTA_PARMS unless marked
otherwise. Device specific parameter sets can be changed by
setting NDTPA_IFINDEX to the interface index of the corresponding
device.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
