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* inetpeer: remove AVL implementation in favor of RB treeEric Dumazet2017-07-171-9/+2
| | | | | | | | | | | | | | | | | | | | | As discussed in Faro during Netfilter Workshop 2017, RB trees can be used with RCU, using a seqlock. Note that net/rxrpc/conn_service.c is already using this. This patch converts inetpeer from AVL tree to RB tree, since it allows to remove private AVL implementation in favor of shared RB code. $ size net/ipv4/inetpeer.before net/ipv4/inetpeer.after text data bss dec hex filename 3195 40 128 3363 d23 net/ipv4/inetpeer.before 1562 24 0 1586 632 net/ipv4/inetpeer.after The same technique can be used to speed up net/netfilter/nft_set_rbtree.c (removing rwlock contention in fast path) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: convert inet_peer.refcnt from atomic_t to refcount_tReshetova, Elena2017-07-011-2/+2
| | | | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. This conversion requires overall +1 on the whole refcounting scheme. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: tcp: fix inetpeer_set_addr_v4()Eric Dumazet2015-12-161-0/+1
| | | | | | | | | | | | | | | | | David Ahern added a vif field in the a4 part of inetpeer_addr struct. This broke IPv4 TCP fast open client side and more generally tcp metrics cache, because inetpeer_addr_cmp() is now comparing two u32 instead of one. inetpeer_set_addr_v4() needs to properly init vif field, otherwise the comparison result depends on uninitialized data. Fixes: 192132b9a034 ("net: Add support for VRFs to inetpeer cache") Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add support for VRFs to inetpeer cacheDavid Ahern2015-08-281-5/+12
| | | | | | | | | inetpeer caches based on address only, so duplicate IP addresses within a namespace return the same cached entry. Enhance the ipv4 address key to contain both the IPv4 address and VRF device index. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Refactor inetpeer address structDavid Ahern2015-08-281-16/+19
| | | | | | | | | | | | | | Move the inetpeer_addr_base union to inetpeer_addr and drop inetpeer_addr_base. Both the a6 and in6_addr overlays are not needed; drop the __be32 version and rename in6 to a6 for consistency with ipv4. Add a new u32 array to the union which removes the need for the typecast in the compare function and the use of a consistent arg for both ipv4 and ipv6 addresses which makes the compare function more readable. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add helper function to compare inetpeer addressesDavid Ahern2015-08-281-0/+16
| | | | | | | | tcp_metrics and inetpeer both have functions to compare inetpeer addresses. Consolidate into 1 version. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add set,get helpers for inetpeer addressesDavid Ahern2015-08-281-0/+23
| | | | | | | | Use inetpeer set,get helpers in tcp_metrics rather than peeking into the inetpeer_addr struct. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: remove dead codeDavid Ahern2015-08-251-67/+0
| | | | | | | Remove various inlined functions not referenced in the kernel. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: simplify inetpeer_addr_base useJiri Benc2015-03-311-1/+2
| | | | | | | | | In many places, the a6 field is typecasted to struct in6_addr. As the fields are in union anyway, just add in6_addr type to the union and get rid of the typecasting. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: remove dead inetpeer sequence codeWillem de Bruijn2014-09-091-1/+0
| | | | | | | | | | | | | | | | | | | | inetpeer sequence numbers are no longer incremented, so no need to check and flush the tree. The function that increments the sequence number was already dead code and removed in in "ipv4: remove unused function" (068a6e18). Remove the code that checks for a change, too. Verifying that v4_seq and v6_seq are never incremented and thus that flush_check compares bp->flush_seq to 0 is trivial. The second part of the change removes flush_check completely even though bp->flush_seq is exactly !0 once, at initialization. This change is correct because the time this branch is true is when bp->root == peer_avl_empty_rcu, in which the branch and inetpeer_invalidate_tree are a NOOP. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-06-041-1/+0
|\ | | | | | | | | | | | | | | | | | | Conflicts: include/net/inetpeer.h net/ipv6/output_core.c Changes in net were fixing bugs in code removed in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: fix inet_getid() and ipv6_select_ident() bugsEric Dumazet2014-06-021-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed we were sending wrong IPv4 ID in TCP flows when MTU discovery is disabled. Note how GSO/TSO packets do not have monotonically incrementing ID. 06:37:41.575531 IP (id 14227, proto: TCP (6), length: 4396) 06:37:41.575534 IP (id 14272, proto: TCP (6), length: 65212) 06:37:41.575544 IP (id 14312, proto: TCP (6), length: 57972) 06:37:41.575678 IP (id 14317, proto: TCP (6), length: 7292) 06:37:41.575683 IP (id 14361, proto: TCP (6), length: 63764) It appears I introduced this bug in linux-3.1. inet_getid() must return the old value of peer->ip_id_count, not the new one. Lets revert this part, and remove the prevention of a null identification field in IPv6 Fragment Extension Header, which is dubious and not even done properly. Fixes: 87c48fa3b463 ("ipv6: make fragment identifications less predictable") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | inetpeer: get rid of ip_id_countEric Dumazet2014-06-021-20/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ideally, we would need to generate IP ID using a per destination IP generator. linux kernels used inet_peer cache for this purpose, but this had a huge cost on servers disabling MTU discovery. 1) each inet_peer struct consumes 192 bytes 2) inetpeer cache uses a binary tree of inet_peer structs, with a nominal size of ~66000 elements under load. 3) lookups in this tree are hitting a lot of cache lines, as tree depth is about 20. 4) If server deals with many tcp flows, we have a high probability of not finding the inet_peer, allocating a fresh one, inserting it in the tree with same initial ip_id_count, (cf secure_ip_id()) 5) We garbage collect inet_peer aggressively. IP ID generation do not have to be 'perfect' Goal is trying to avoid duplicates in a short period of time, so that reassembly units have a chance to complete reassembly of fragments belonging to one message before receiving other fragments with a recycled ID. We simply use an array of generators, and a Jenkin hash using the dst IP as a key. ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it belongs (it is only used from this file) secure_ip_id() and secure_ipv6_id() no longer are needed. Rename ip_select_ident_more() to ip_select_ident_segs() to avoid unnecessary decrement/increment of the number of segments. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: remove unused functionStephen Hemminger2013-12-281-1/+0
| | | | | | | inetpeer_invalidate_family defined but never used Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet*.h: Remove extern from function prototypesJoe Perches2013-09-211-6/+6
| | | | | | | | | | | | | 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. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Maintain redirect and PMTU info in struct rtable again.David S. Miller2012-07-111-4/+0
| | | | | | | Maintaining this in the inetpeer entries was not the right way to do this at all. Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Move timestamps from inetpeer to metrics cache.David S. Miller2012-07-111-3/+1
| | | | | | With help from Lin Ming. Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Avoid potential NULL peer dereference.David S. Miller2012-06-111-1/+1
| | | | | | | | | | | We handle NULL in rt{,6}_set_peer but then our caller will try to pass that NULL pointer into inet_putpeer() which isn't ready for it. Fix this by moving the NULL check one level up, and then remove the now unnecessary NULL check from inetpeer_ptr_set_peer(). Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Add family scope inetpeer flushes.David S. Miller2012-06-111-0/+2
| | | | | | | | | | | | | | This implementation can deal with having many inetpeer roots, which is a necessary prerequisite for per-FIB table rooted peer tables. Each family (AF_INET, AF_INET6) has a sequence number which we bump when we get a family invalidation request. Each peer lookup cheaply checks whether the flush sequence of the root we are using is out of date, and if so flushes it and updates the sequence number. Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Hide route peer accesses behind helpers.David S. Miller2012-06-111-0/+54
| | | | | | | | | | | | We encode the pointer(s) into an unsigned long with one state bit. The state bit is used so we can store the inetpeer tree root to use when resolving the peer later. Later the peer roots will be per-FIB table, and this change works to facilitate that. Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Pass inetpeer root into inet_getpeer*() interfaces.David S. Miller2012-06-101-5/+5
| | | | | | | Otherwise we reference potentially non-existing members when ipv6 is disabled. Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Consolidate inetpeer_invalidate_tree() interfaces.David S. Miller2012-06-101-2/+1
| | | | | | | We only need one interface for this operation, since we always know which inetpeer root we want to flush. Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: Initialize per-netns inetpeer roots in net/ipv{4,6}/route.cDavid S. Miller2012-06-101-0/+9
| | | | | | Instead of net/ipv4/inetpeer.c Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: add parameter net for inet_getpeer_v4,v6Gao feng2012-06-081-4/+8
| | | | | | | | | | add struct net as a parameter of inet_getpeer_v[4,6], use net to replace &init_net. and modify some places to provide net for inet_getpeer_v[4,6] Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: add namespace support for inetpeerGao feng2012-06-081-4/+6
| | | | | | | | | | | | | | | | now inetpeer doesn't support namespace,the information will be leaking across namespace. this patch move the global vars v4_peers and v6_peers to netns_ipv4 and netns_ipv6 as a field peers. add struct pernet_operations inetpeer_ops to initial pernet inetpeer data. and change family_to_base and inet_getpeer to support namespace. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: fix a race in inetpeer_gc_worker()Eric Dumazet2012-06-061-1/+4
| | | | | | | | | | | | | | | | | commit 5faa5df1fa2024 (inetpeer: Invalidate the inetpeer tree along with the routing cache) added a race : Before freeing an inetpeer, we must respect a RCU grace period, and make sure no user will attempt to increase refcnt. inetpeer_invalidate_tree() waits for a RCU grace period before inserting inetpeer tree into gc_list and waking the worker. At that time, no concurrent lookup can find a inetpeer in this tree. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* route: Remove redirect_genidSteffen Klassert2012-03-081-1/+0
| | | | | | | | | As we invalidate the inetpeer tree along with the routing cache now, we don't need a genid to reset the redirect handling when the routing cache is flushed. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Invalidate the inetpeer tree along with the routing cacheSteffen Klassert2012-03-081-0/+3
| | | | | | | | | | | | We initialize the routing metrics with the values cached on the inetpeer in rt_init_metrics(). So if we have the metrics cached on the inetpeer, we ignore the user configured fib_metrics. To fix this issue, we replace the old tree with a fresh initialized inet_peer_base. The old tree is removed later with a delayed work queue. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-12-021-0/+1
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| * inet: add a redirect generation id in inetpeerEric Dumazet2011-11-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now inetpeer is the place where we cache redirect information for ipv4 destinations, we must be able to invalidate informations when a route is added/removed on host. As inetpeer is not yet namespace aware, this patch adds a shared redirect_genid, and a per inetpeer redirect_genid. This might be changed later if inetpeer becomes ns aware. Cache information for one inerpeer is valid as long as its redirect_genid has the same value than global redirect_genid. Reported-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com> Tested-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: remove ipv6_addr_copy()Alexey Dobriyan2011-11-221-1/+1
|/ | | | | | | 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>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-271-1/+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>
* ipv6: make fragment identifications less predictableEric Dumazet2011-07-221-3/+10
| | | | | | | | | | | | | | | | | | IPv6 fragment identification generation is way beyond what we use for IPv4 : It uses a single generator. Its not scalable and allows DOS attacks. Now inetpeer is IPv6 aware, we can use it to provide a more secure and scalable frag ident generator (per destination, instead of system wide) This patch : 1) defines a new secure_ipv6_id() helper 2) extends inet_getid() to provide 32bit results 3) extends ipv6_select_ident() with a new dest parameter Reported-by: Fernando Gont <fernando@gont.com.ar> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: lower false sharing effectEric Dumazet2011-06-091-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Profiles show false sharing in addr_compare() because refcnt/dtime changes dirty the first inet_peer cache line, where are lying the keys used at lookup time. If many cpus are calling inet_getpeer() and inet_putpeer(), or need frag ids, addr_compare() is in 2nd position in "perf top". Before patch, my udpflood bench (16 threads) on my 2x4x2 machine : 5784.00 9.7% csum_partial_copy_generic [kernel] 3356.00 5.6% addr_compare [kernel] 2638.00 4.4% fib_table_lookup [kernel] 2625.00 4.4% ip_fragment [kernel] 1934.00 3.2% neigh_lookup [kernel] 1617.00 2.7% udp_sendmsg [kernel] 1608.00 2.7% __ip_route_output_key [kernel] 1480.00 2.5% __ip_append_data [kernel] 1396.00 2.3% kfree [kernel] 1195.00 2.0% kmem_cache_free [kernel] 1157.00 1.9% inet_getpeer [kernel] 1121.00 1.9% neigh_resolve_output [kernel] 1012.00 1.7% dev_queue_xmit [kernel] # time ./udpflood.sh real 0m44.511s user 0m20.020s sys 11m22.780s # time ./udpflood.sh real 0m44.099s user 0m20.140s sys 11m15.870s After patch, no more addr_compare() in profiles : 4171.00 10.7% csum_partial_copy_generic [kernel] 1787.00 4.6% fib_table_lookup [kernel] 1756.00 4.5% ip_fragment [kernel] 1234.00 3.2% udp_sendmsg [kernel] 1191.00 3.0% neigh_lookup [kernel] 1118.00 2.9% __ip_append_data [kernel] 1022.00 2.6% kfree [kernel] 993.00 2.5% __ip_route_output_key [kernel] 841.00 2.2% neigh_resolve_output [kernel] 816.00 2.1% kmem_cache_free [kernel] 658.00 1.7% ia32_sysenter_target [kernel] 632.00 1.6% kmem_cache_alloc_node [kernel] # time ./udpflood.sh real 0m41.587s user 0m19.190s sys 10m36.370s # time ./udpflood.sh real 0m41.486s user 0m19.290s sys 10m33.650s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: remove unused listEric Dumazet2011-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Andi Kleen and Tim Chen reported huge contention on inetpeer unused_peers.lock, on memcached workload on a 40 core machine, with disabled route cache. It appears we constantly flip peers refcnt between 0 and 1 values, and we must insert/remove peers from unused_peers.list, holding a contended spinlock. Remove this list completely and perform a garbage collection on-the-fly, at lookup time, using the expired nodes we met during the tree traversal. This removes a lot of code, makes locking more standard, and obsoletes two sysctls (inet_peer_gc_mintime and inet_peer_gc_maxtime). This also removes two pointers in inet_peer structure. There is still a false sharing effect because refcnt is in first cache line of object [were the links and keys used by lookups are located], we might move it at the end of inet_peer structure to let this first cache line mostly read by cpus. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Andi Kleen <andi@firstfloor.org> CC: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: constify ip headers and in6_addrEric Dumazet2011-04-221-1/+1
| | | | | | | | Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers where possible, to make code intention more obvious. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Add redirect and PMTU discovery cached info.David S. Miller2011-02-101-7/+11
| | | | | | | | | | | | | | | | | Validity of the cached PMTU information is indicated by it's expiration value being non-zero, just as per dst->expires. The scheme we will use is that we will remember the pre-ICMP value held in the metrics or route entry, and then at expiration time we will restore that value. In this way PMTU expiration does not kill off the cached route as is done currently. Redirect information is permanent, or at least until another redirect is received. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Abstract address representation further.David S. Miller2011-02-101-6/+10
| | | | | | | | | | | Future changes will add caching information, and some of these new elements will be addresses. Since the family is implicit via the ->daddr.family member, replicating the family in ever address we store is entirely redundant. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Move ICMP rate limiting state into inet_peer entries.David S. Miller2011-02-051-0/+3
| | | | | | | | | | Like metrics, the ICMP rate limiting bits are cached state about a destination. So move it into the inet_peer entries. If an inet_peer cannot be bound (the reason is memory allocation failure or similar), the policy is to allow. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Mark metrics as "new" in fresh inetpeer entries.David S. Miller2011-01-271-0/+7
| | | | | | | | | | Set the RTAX_LOCKED metric to INETPEER_METRICS_NEW (basically, all ones) on fresh inetpeer entries. This way code can determine if default metrics have been loaded in from a routing table entry already. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Add metrics storage to inetpeer entries.David S. Miller2011-01-271-2/+4
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Fix incorrect comment about inetpeer struct size.David S. Miller2010-12-021-1/+0
| | | | | | Now with ipv6 support it is no longer less than 64 bytes. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Kill use of inet_peer_address_t typedef.David S. Miller2010-12-021-6/+6
| | | | | | They are verboten these days. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Add inet_getpeer_v6()David S. Miller2010-11-301-0/+10
| | | | | | | Now that all of the infrastructure is in place, we can add the ipv6 shorthand for peer creation. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Make inet_getpeer() take an inet_peer_adress_t pointer.David S. Miller2010-11-301-1/+10
| | | | | | And make an inet_getpeer_v4() helper, update callers. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Introduce inet_peer_address_t.David S. Miller2010-11-301-1/+9
| | | | | | Currently only the v4 aspect is used, but this will change. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: __rcu annotationsEric Dumazet2010-10-271-1/+1
| | | | | | | | | | | | | | | Adds __rcu annotations to inetpeer (struct inet_peer)->avl_left (struct inet_peer)->avl_right This is a tedious cleanup, but removes one smp_wmb() from link_to_pool() since we now use more self documenting rcu_assign_pointer(). Note the use of RCU_INIT_POINTER() instead of rcu_assign_pointer() in all cases we dont need a memory barrier. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: restore small inet_peer structuresEric Dumazet2010-06-161-5/+26
| | | | | | | | | | | | | | | | | Addition of rcu_head to struct inet_peer added 16bytes on 64bit arches. Thats a bit unfortunate, since old size was exactly 64 bytes. This can be solved, using an union between this rcu_head an four fields, that are normally used only when a refcount is taken on inet_peer. rcu_head is used only when refcnt=-1, right before structure freeing. Add a inet_peer_refcheck() function to check this assertion for a while. We can bring back SLAB_HWCACHE_ALIGN qualifier in kmem cache creation. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: RCU conversionEric Dumazet2010-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inetpeer currently uses an AVL tree protected by an rwlock. It's possible to make most lookups use RCU 1) Add a struct rcu_head to struct inet_peer 2) add a lookup_rcu_bh() helper to perform lockless and opportunistic lookup. This is a normal function, not a macro like lookup(). 3) Add a limit to number of links followed by lookup_rcu_bh(). This is needed in case we fall in a loop. 4) add an smp_wmb() in link_to_pool() right before node insert. 5) make unlink_from_pool() use atomic_cmpxchg() to make sure it can take last reference to an inet_peer, since lockless readers could increase refcount, even while we hold peers.lock. 6) Delay struct inet_peer freeing after rcu grace period so that lookup_rcu_bh() cannot crash. 7) inet_getpeer() first attempts lockless lookup. Note this lookup can fail even if target is in AVL tree, but a concurrent writer can let tree in a non correct form. If this attemps fails, lock is taken a regular lookup is performed again. 8) convert peers.lock from rwlock to a spinlock 9) Remove SLAB_HWCACHE_ALIGN when peer_cachep is created, because rcu_head adds 16 bytes on 64bit arches, doubling effective size (64 -> 128 bytes) In a future patch, this is probably possible to revert this part, if rcu field is put in an union to share space with rid, ip_id_count, tcp_ts & tcp_ts_stamp. These fields being manipulated only with refcnt > 0. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Optimize inet_getid()Eric Dumazet2009-11-141-11/+5
| | | | | | | | | | | | | | | While investigating for network latencies, I found inet_getid() was a contention point for some workloads, as inet_peer_idlock is shared by all inet_getid() users regardless of peers. One way to fix this is to make ip_id_count an atomic_t instead of __u16, and use atomic_add_return(). In order to keep sizeof(struct inet_peer) = 64 on 64bit arches tcp_ts_stamp is also converted to __u32 instead of "unsigned long". Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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