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2015-08-10net: add explicit logging and stat for neighbour table overflowRick Jones1-0/+1
Add an explicit neighbour table overflow message (ratelimited) and statistic to make diagnosing neighbour table overflows tractable in the wild. Diagnosing a neighbour table overflow can be quite difficult in the wild because there is no explicit dmesg logged. Callers to neighbour code seem to use net_dbg_ratelimit when the neighbour call fails which means the "base message" is not emitted and the callback suppressed messages from the ratelimiting can end-up juxtaposed with unrelated messages. Further, a forced garbage collection will increment a stat on each call whether it was successful in freeing-up a table entry or not, so that statistic is only a hint. So, add a net_info_ratelimited message and explicit statistic to the neighbour code. Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-21net: neighbour: Add mcast_resolicit to configure the number of multicast ↵YOSHIFUJI Hideaki/吉藤英明1-0/+1
resolicitations in PROBE state. We send unicast neighbor (ARP or NDP) solicitations ucast_probes times in PROBE state. Zhu Yanjun reported that some implementation does not reply against them and the entry will become FAILED, which is undesirable. We had been dealt with such nodes by sending multicast probes mcast_ solicit times after unicast probes in PROBE state. In 2003, I made a change not to send them to improve compatibility with IPv6 NDP. Let's introduce per-protocol per-interface sysctl knob "mcast_ reprobe" to configure the number of multicast (re)solicitation for reconfirmation in PROBE state. The default is 0, since we have been doing so for 10+ years. Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com> CC: Ulf Samuelsson <ulf.samuelsson@ericsson.com> Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12net: Introduce possible_net_tEric W. Biederman1-6/+2
Having to say > #ifdef CONFIG_NET_NS > struct net *net; > #endif in structures is a little bit wordy and a little bit error prone. Instead it is possible to say: > typedef struct { > #ifdef CONFIG_NET_NS > struct net *net; > #endif > } possible_net_t; And then in a header say: > possible_net_t net; Which is cleaner and easier to use and easier to test, as the possible_net_t is always there no matter what the compile options. Further this allows read_pnet and write_pnet to be functions in all cases which is better at catching typos. This change adds possible_net_t, updates the definitions of read_pnet and write_pnet, updates optional struct net * variables that write_pnet uses on to have the type possible_net_t, and finally fixes up the b0rked users of read_pnet and write_pnet. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09neigh: Use neigh table index for neigh_packet_xmitEric W. Biederman1-0/+1
Remove a little bit of unnecessary work when transmitting a packet with neigh_packet_xmit. Use the neighbour table index not the address family as a parameter. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04neigh: Add helper function neigh_xmitEric W. Biederman1-0/+3
For MPLS I am building the code so that either the neighbour mac address can be specified or we can have a next hop in ipv4 or ipv6. The kind of next hop we have is indicated by the neighbour table pointer. A neighbour table pointer of NULL is a link layer address. A non-NULL neighbour table pointer indicates which neighbour table and thus which address family the next hop address is in that we need to look up. The code either sends a packet directly or looks up the appropriate neighbour table entry and sends the packet. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04neigh: Factor out ___neigh_lookup_norefEric W. Biederman1-0/+52
While looking at the mpls code I found myself writing yet another version of neigh_lookup_noref. We currently have __ipv4_lookup_noref and __ipv6_lookup_noref. So to make my work a little easier and to make it a smidge easier to verify/maintain the mpls code in the future I stopped and wrote ___neigh_lookup_noref. Then I rewote __ipv4_lookup_noref and __ipv6_lookup_noref in terms of this new function. I tested my new version by verifying that the same code is generated in ip_finish_output2 and ip6_finish_output2 where these functions are inlined. To get to ___neigh_lookup_noref I added a new neighbour cache table function key_eq. So that the static size of the key would be available. I also added __neigh_lookup_noref for people who want to to lookup a neighbour table entry quickly but don't know which neibhgour table they are going to look up. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-03neigh: Don't require dst in neigh_hh_initEric W. Biederman1-0/+1
- Add protocol to neigh_tbl so that dst->ops->protocol is not needed - Acquire the device from neigh->dev This results in a neigh_hh_init that will cache the samve values regardless of the packets flowing through it. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-03neigh: Move neigh_compat_output into ax25_ip.cEric W. Biederman1-1/+0
The only caller is now is ax25_neigh_construct so move neigh_compat_output into ax25_ip.c make it static and rename it ax25_neigh_output. Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-hams@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27neigh: remove next ptr from struct neigh_tableNicolas Dichtel1-1/+0
After commit d7480fd3b173 ("neigh: remove dynamic neigh table registration support"), this field is not used anymore. CC: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-11neigh: remove dynamic neigh table registration supportWANG Cong1-2/+9
Currently there are only three neigh tables in the whole kernel: arp table, ndisc table and decnet neigh table. What's more, we don't support registering multiple tables per family. Therefore we can just make these tables statically built-in. Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-29neigh: optimize neigh_parms_release()Nicolas Dichtel1-1/+2
In neigh_parms_release() we loop over all entries to find the entry given in argument and being able to remove it from the list. By using a double linked list, we can avoid this loop. Here are some numbers with 30 000 dummy interfaces configured: Before the patch: $ time rmmod dummy real 2m0.118s user 0m0.000s sys 1m50.048s After the patch: $ time rmmod dummy real 1m9.970s user 0m0.000s sys 0m47.976s Suggested-by: Thierry Herbelot <thierry.herbelot@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26netfilter: bridge: move br_netfilter out of the corePablo Neira Ayuso1-1/+1
Jesper reported that br_netfilter always registers the hooks since this is part of the bridge core. This harms performance for people that don't need this. This patch modularizes br_netfilter so it can be rmmod'ed, thus, the hooks can be unregistered. I think the bridge netfilter should have been a separated module since the beginning, Patrick agreed on that. Note that this is breaking compatibility for users that expect that bridge netfilter is going to be available after explicitly 'modprobe bridge' or via automatic load through brctl. However, the damage can be easily undone by modprobing br_netfilter. The bridge core also spots a message to provide a clue to people that didn't notice that this has been deprecated. On top of that, the plan is that nftables will not rely on this software layer, but integrate the connection tracking into the bridge layer to enable stateful filtering and NAT, which is was bridge netfilter users seem to require. This patch still keeps the fake_dst_ops in the bridge core, since this is required by when the bridge port is initialized. So we can safely modprobe/rmmod br_netfilter anytime. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Florian Westphal <fw@strlen.de>
2014-07-15neigh: sysctl - simplify address calculation of gc_* variablesMathias Krause1-1/+0
The code in neigh_sysctl_register() relies on a specific layout of struct neigh_table, namely that the 'gc_*' variables are directly following the 'parms' member in a specific order. The code, though, expresses this in the most ugly way. Get rid of the ugly casts and use the 'tbl' pointer to get a handle to the table. This way we can refer to the 'gc_*' variables directly. Similarly seen in the grsecurity patch, written by Brad Spengler. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-16neigh: use NEIGH_VAR_INIT in ndo_neigh_setup functions.Jiri Pirko1-0/+5
When ndo_neigh_setup is called, the bitfield used by NEIGH_VAR_SET is not initialized yet. This might cause confusion for the people who use NEIGH_VAR_SET in ndo_neigh_setup. So rather introduce NEIGH_VAR_INIT for usage in ndo_neigh_setup. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12ipv6: router reachability probingJiri Benc1-0/+1
RFC 4191 states in 3.5: When a host avoids using any non-reachable router X and instead sends a data packet to another router Y, and the host would have used router X if router X were reachable, then the host SHOULD probe each such router X's reachability by sending a single Neighbor Solicitation to that router's address. A host MUST NOT probe a router's reachability in the absence of useful traffic that the host would have sent to the router if it were reachable. In any case, these probes MUST be rate-limited to no more than one per minute per router. Currently, when the neighbour corresponding to a router falls into NUD_FAILED, it's never considered again. Introduce a new rt6_nud_state value, RT6_NUD_FAIL_PROBE, which suggests the route should not be used but should be probed with a single NS. The probe is ratelimited by the existing code. To better distinguish meanings of the failure values, rename RT6_NUD_FAIL_SOFT to RT6_NUD_FAIL_DO_RR. Signed-off-by: Jiri Benc <jbenc@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-10neigh: restore old behaviour of default parms valuesJiri Pirko1-0/+13
Previously inet devices were only constructed when addresses are added. Therefore the default neigh parms values they get are the ones at the time of these operations. Now that we're creating inet devices earlier, this changes the behaviour of default neigh parms values in an incompatible way (see bug #8519). This patch creates a compromise by setting the default values at the same point as before but only for those that have not been explicitly set by the user since the inet device's creation. Introduced by: commit 8030f54499925d073a88c09f30d5d844fb1b3190 Author: Herbert Xu <herbert@gondor.apana.org.au> Date: Thu Feb 22 01:53:47 2007 +0900 [IPV4] devinet: Register inetdev earlier. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-10neigh: use tbl->family to distinguish ipv4 from ipv6Jiri Pirko1-1/+6
Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-10neigh: wrap proc dointvec functionsJiri Pirko1-0/+9
This will be needed later on to provide better management of default values. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-10neigh: convert parms to an arrayJiri Pirko1-13/+35
This patch converts the neigh param members to an array. This allows easier manipulation which will be needed later on to provide better management of default values. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-01arp/neighbour.h: Remove extern from function prototypesJoe Perches1-50/+48
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Reflow modified prototypes to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-11net neighbour, decnet: Ensure to align device private data on preferred ↵YOSHIFUJI Hideaki / 吉藤英明1-0/+1
alignment. To allow both of protocol-specific data and device-specific data attached with neighbour entry, and to eliminate size calculation cost when allocating entry, sizeof protocol-speicic data must be multiple of NEIGH_PRIV_ALIGN. On 64bit archs, sizeof(struct dn_neigh) is multiple of NEIGH_PRIV_ALIGN, but on 32bit archs, it was not. Introduce NEIGH_ENTRY_SPACE() macro to ensure that protocol-specific entry-size meets our requirement. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-29net neigh: Optimize neighbor entry size calculation.YOSHIFUJI Hideaki / 吉藤英明1-1/+1
When allocating memory for neighbour cache entry, if tbl->entry_size is not set, we always calculate sizeof(struct neighbour) + tbl->key_len, which is common in the same table. With this change, set tbl->entry_size during the table initialization phase, if it was not set, and use it in neigh_alloc() and neighbour_priv(). This change also allow us to have both of protocol private data and device priate data at tha same time. Note that the only user of prototcol private is DECnet and the only user of device private is ATM CLIP. Since those are exclusive, we have not been facing issues here. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-08net: output path optimizationsEric Dumazet1-5/+9
1) Avoid dirtying neighbour's confirmed field. TCP workloads hits this cache line for each incoming ACK. Lets write n->confirmed only if there is a jiffie change. 2) Optimize neigh_hh_output() for the common Ethernet case, were hh_len is less than 16 bytes. Replace the memcpy() call by two inlined 64bit load/stores on x86_64. Bench results using udpflood test, with -C option (MSG_CONFIRM flag added to sendto(), to reproduce the n->confirmed dirtying on UDP) 24 threads doing 1.000.000 UDP sendto() on dummy device, 4 runs. before : 2.247s, 2.235s, 2.247s, 2.318s after : 1.884s, 1.905s, 1.891s, 1.895s Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05net: Do delayed neigh confirmation.David S. Miller1-15/+0
When a dst_confirm() happens, mark the confirmation as pending in the dst. Then on the next packet out, when we have the neigh in-hand, do the update. This removes the dependency in dst_confirm() of dst's having an attached neigh. While we're here, remove the explicit 'dst' NULL check, all except 2 or 3 call sites ensure it's not NULL. So just fix those cases up. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05ipv4: Make neigh lookups directly in output packet path.David S. Miller1-2/+9
Do not use the dst cached neigh, we'll be getting rid of that. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15net: cleanup unsigned to unsigned intEric Dumazet1-2/+2
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13neighbour: Make neigh_table_init_no_netlink() static.Hiroaki SHIMODA1-1/+0
neigh_table_init_no_netlink() is only used in net/core/neighbour.c file. Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-29ipv6: Use universal hash for NDISC.David S. Miller1-2/+4
In order to perform a proper universal hash on a vector of integers, we have to use different universal hashes on each vector element. Which means we need 4 different hash randoms for ipv6. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20Revert "net: Remove unused neighbour layer ops."David S. Miller1-0/+1
This reverts commit 5c3ddec73d01a1fae9409c197078cb02c42238c3. S390 qeth driver actually still uses the setup ops. Reported-by: Frank Blaschka <blaschka@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-14net: Remove unused neighbour layer ops.David S. Miller1-1/+0
It's simpler to just keep these things out until there is a real user of them, so we can see what the needs actually are, rather than keep these things around as useless overhead. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01neigh: Get rid of neigh_table->kmem_cachepDavid Miller1-1/+0
We are going to alloc for device specific private areas for neighbour entries, and in order to do that we have to move away from the fixed allocation size enforced by using neigh_table->kmem_cachep As a nice side effect we can now use kfree_rcu(). Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01neigh: Create mechanism for generic neigh private areas.David Miller1-0/+7
The implementation private sits right after the primary_key memory. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-14neigh: new unresolved queue limitsEric Dumazet1-1/+2
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>
2011-07-27atomic: use <linux/atomic.h>Arun Sharma1-1/+1
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-18neigh: Pass neighbour entry to output ops.David S. Miller1-9/+10
This will get us closer to being able to do "neigh stuff" completely independent of the underlying dst_entry for protocols (ipv4/ipv6) that wish to do so. We will also be able to make dst entries neigh-less. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17neigh: Kill ndisc_ops->queue_xmitDavid S. Miller1-1/+0
It is always dev_queue_xmit(). Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17neigh: Kill hh_cache->hh_outputDavid S. Miller1-2/+2
It's just taking on one of two possible values, either neigh_ops->output or dev_queue_xmit(). And this is purely depending upon whether nud_state has NUD_CONNECTED set or not. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17neigh: Kill neigh_ops->hh_outputDavid S. Miller1-1/+0
It's always dev_queue_xmit(). Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17net: Create and use new helper, neigh_output().David S. Miller1-0/+9
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-14net: Embed hh_cache inside of struct neighbour.David S. Miller1-1/+1
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>
2011-07-11neigh: Store hash shift instead of mask.David S. Miller1-1/+1
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>
2010-11-20Merge branch 'master' of ↵David S. Miller1-1/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bonding/bond_main.c net/core/net-sysfs.c net/ipv6/addrconf.c
2010-11-18net: Fix duplicate volatile warning.Tetsuo Handa1-1/+1
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>
2010-11-11neigh: reorder struct neighbourEric Dumazet1-5/+5
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 0ed8ddf4045f (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>
2010-10-12neigh: reorder struct neighbour fieldsEric Dumazet1-4/+4
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>
2010-10-11neigh: Protect neigh->ha[] with a seqlockEric Dumazet1-1/+15
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>
2010-10-07neigh: RCU conversion of struct neighbourEric Dumazet1-2/+3
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>
2010-10-06net neigh: RCU conversion of neigh hash tableEric Dumazet1-4/+12
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>
2010-10-01neigh: reorder fields in struct neighbourEric Dumazet1-3/+3
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>
2010-06-30net/neighbour.h: fix typoKulikov Vasiliy1-1/+1
'Shoul' must be 'should'. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>