Commit graph

64 commits

Author SHA1 Message Date
Linus Torvalds
033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00
Nicolas Dichtel
bc9259a8ba inetpeer: fix token initialization
When jiffies wraps around (for example, 5 minutes after the boot, see
INITIAL_JIFFIES) and peer has just been created, now - peer->rate_last can be
< XRLIM_BURST_FACTOR * timeout, so token is not set to the maximum value, thus
some icmp packets can be unexpectedly dropped.

Fix this case by initializing last_rate to 60 seconds in the past.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-27 19:27:39 -04:00
Tejun Heo
203b42f731 workqueue: make deferrable delayed_work initializer names consistent
Initalizers for deferrable delayed_work are confused.

* __DEFERRED_WORK_INITIALIZER()
* DECLARE_DEFERRED_WORK()
* INIT_DELAYED_WORK_DEFERRABLE()

Rename them to

* __DEFERRABLE_WORK_INITIALIZER()
* DECLARE_DEFERRABLE_WORK()
* INIT_DEFERRABLE_WORK()

This patch doesn't cause any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
2012-08-21 13:18:23 -07:00
David S. Miller
5943634fc5 ipv4: Maintain redirect and PMTU info in struct rtable again.
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>
2012-07-10 22:40:14 -07:00
David S. Miller
81166dd6fa tcp: Move timestamps from inetpeer to metrics cache.
With help from Lin Ming.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:08 -07:00
Eric Dumazet
da55737467 inetpeer: inetpeer_invalidate_tree() cleanup
No need to use cmpxchg() in inetpeer_invalidate_tree() since we hold
base lock.

Also use correct rcu annotations to remove sparse errors
(CONFIG_SPARSE_RCU_POINTER=y)

net/ipv4/inetpeer.c:144:19: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:149:20: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:595:10: error: incompatible types in comparison
expression (different address spaces)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-20 14:38:55 -07:00
David S. Miller
b48c80ece9 inet: Add family scope inetpeer flushes.
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>
2012-06-11 02:09:10 -07:00
David S. Miller
c0efc887dc inet: Pass inetpeer root into inet_getpeer*() interfaces.
Otherwise we reference potentially non-existing members when
ipv6 is disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 19:12:36 -07:00
David S. Miller
56a6b248eb inet: Consolidate inetpeer_invalidate_tree() interfaces.
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>
2012-06-09 16:32:41 -07:00
David S. Miller
c3426b4719 inet: Initialize per-netns inetpeer roots in net/ipv{4,6}/route.c
Instead of net/ipv4/inetpeer.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 16:27:05 -07:00
Gao feng
c8a627ed06 inetpeer: add namespace support for inetpeer
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>
2012-06-08 14:27:23 -07:00
Eric Dumazet
55432d2b54 inetpeer: fix a race in inetpeer_gc_worker()
commit 5faa5df1fa (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>
2012-06-06 10:45:15 -07:00
Steffen Klassert
ac3f48de09 route: Remove redirect_genid
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>
2012-03-08 00:30:32 -08:00
Steffen Klassert
5faa5df1fa inetpeer: Invalidate the inetpeer tree along with the routing cache
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>
2012-03-08 00:30:24 -08:00
Dan Carpenter
10ec1bb7e9 inetpeer: initialize ->redirect_genid in inet_getpeer()
kmemcheck complains that ->redirect_genid doesn't get initialized.
Presumably it should be set to zero.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-17 15:52:12 -05:00
Eric Dumazet
747465ef7a net: fix some sparse errors
make C=2 CF="-D__CHECK_ENDIAN__" M=net

And fix flowi4_init_output() prototype for sport

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-17 10:31:12 -05:00
David S. Miller
6e5714eaf7 net: Compute protocol sequence numbers and fragment IDs using MD5.
Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-06 18:33:19 -07:00
Eric Dumazet
87c48fa3b4 ipv6: make fragment identifications less predictable
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>
2011-07-21 21:25:58 -07:00
Eric Dumazet
6d1a3e042f inetpeer: kill inet_putpeer race
We currently can free inetpeer entries too early :

[  782.636674] WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (f130f44c)
[  782.636677] 1f7b13c100000000000000000000000002000000000000000000000000000000
[  782.636686]  i i i i u u u u i i i i u u u u i i i i u u u u u u u u u u u u
[  782.636694]                          ^
[  782.636696]
[  782.636698] Pid: 4638, comm: ssh Not tainted 3.0.0-rc5+ #270 Hewlett-Packard HP Compaq 6005 Pro SFF PC/3047h
[  782.636702] EIP: 0060:[<c13fefbb>] EFLAGS: 00010286 CPU: 0
[  782.636707] EIP is at inet_getpeer+0x25b/0x5a0
[  782.636709] EAX: 00000002 EBX: 00010080 ECX: f130f3c0 EDX: f0209d30
[  782.636711] ESI: 0000bc87 EDI: 0000ea60 EBP: f0209ddc ESP: c173134c
[  782.636712]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  782.636714] CR0: 8005003b CR2: f0beca80 CR3: 30246000 CR4: 000006d0
[  782.636716] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[  782.636717] DR6: ffff4ff0 DR7: 00000400
[  782.636718]  [<c13fbf76>] rt_set_nexthop.clone.45+0x56/0x220
[  782.636722]  [<c13fc449>] __ip_route_output_key+0x309/0x860
[  782.636724]  [<c141dc54>] tcp_v4_connect+0x124/0x450
[  782.636728]  [<c142ce43>] inet_stream_connect+0xa3/0x270
[  782.636731]  [<c13a8da1>] sys_connect+0xa1/0xb0
[  782.636733]  [<c13a99dd>] sys_socketcall+0x25d/0x2a0
[  782.636736]  [<c149deb8>] sysenter_do_call+0x12/0x28
[  782.636738]  [<ffffffff>] 0xffffffff

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-11 20:25:04 -07:00
Eric Dumazet
4b9d9be839 inetpeer: remove unused list
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>
2011-06-08 17:05:30 -07:00
Eric Dumazet
686a7e32ca inetpeer: fix race in unused_list manipulations
Several crashes in cleanup_once() were reported in recent kernels.

Commit d6cc1d642d (inetpeer: various changes) added a race in
unlink_from_unused().

One way to avoid taking unused_peers.lock before doing the list_empty()
test is to catch 0->1 refcnt transitions, using full barrier atomic
operations variants (atomic_cmpxchg() and atomic_inc_return()) instead
of previous atomic_inc() and atomic_add_unless() variants.

We then call unlink_from_unused() only for the owner of the 0->1
transition.

Add a new atomic_add_unless_return() static helper

With help from Arun Sharma.

Refs: https://bugzilla.kernel.org/show_bug.cgi?id=32772

Reported-by: Arun Sharma <asharma@fb.com>
Reported-by: Maximilian Engelhardt <maxi@daemonizer.de>
Reported-by: Yann Dupont <Yann.Dupont@univ-nantes.fr>
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-27 13:39:11 -04:00
Eric Dumazet
66944e1c57 inetpeer: reduce stack usage
On 64bit arches, we use 752 bytes of stack when cleanup_once() is called
from inet_getpeer().

Lets share the avl stack to save ~376 bytes.

Before patch :

# objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl

0x000006c3 unlink_from_pool [inetpeer.o]:		376
0x00000721 unlink_from_pool [inetpeer.o]:		376
0x00000cb1 inet_getpeer [inetpeer.o]:			376
0x00000e6d inet_getpeer [inetpeer.o]:			376
0x0004 inet_initpeers [inetpeer.o]:			112
# size net/ipv4/inetpeer.o
   text	   data	    bss	    dec	    hex	filename
   5320	    432	     21	   5773	   168d	net/ipv4/inetpeer.o

After patch :

objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl
0x00000c11 inet_getpeer [inetpeer.o]:			376
0x00000dcd inet_getpeer [inetpeer.o]:			376
0x00000ab9 peer_check_expire [inetpeer.o]:		328
0x00000b7f peer_check_expire [inetpeer.o]:		328
0x0004 inet_initpeers [inetpeer.o]:			112
# size net/ipv4/inetpeer.o
   text	   data	    bss	    dec	    hex	filename
   5163	    432	     21	   5616	   15f0	net/ipv4/inetpeer.o

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Scot Doyle <lkml@scotdoyle.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Reviewed-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-12 13:58:33 -07:00
Eric Dumazet
4e75db2e8f inetpeer: should use call_rcu() variant
After commit 7b46ac4e77 (inetpeer: Don't disable BH for initial
fast RCU lookup.), we should use call_rcu() to wait proper RCU grace
period.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-13 23:22:23 -07:00
Hiroaki SHIMODA
46af31800b ipv4: Fix PMTU update.
On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),

  icmp_unreach
    -> ip_rt_frag_needed
         (peer->pmtu_expires is set here)
    -> tcp_v4_err
         -> do_pmtu_discovery
              -> ip_rt_update_pmtu
                   (peer->pmtu_expires is already set,
                    so check_peer_pmtu is skipped.)
                   -> check_peer_pmtu

check_peer_pmtu is skipped and MTU is not updated.

To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
   but not initialized.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-13 18:37:49 -07:00
David S. Miller
7b46ac4e77 inetpeer: Don't disable BH for initial fast RCU lookup.
If modifications on other cpus are ok, then modifications to
the tree during lookup done by the local cpu are ok too.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-08 14:59:28 -08:00
Eric Dumazet
65e8354ec1 inetpeer: seqlock optimization
David noticed :

------------------
Eric, I was profiling the non-routing-cache case and something that
stuck out is the case of calling inet_getpeer() with create==0.

If an entry is not found, we have to redo the lookup under a spinlock
to make certain that a concurrent writer rebalancing the tree does
not "hide" an existing entry from us.

This makes the case of a create==0 lookup for a not-present entry
really expensive.  It is on the order of 600 cpu cycles on my
Niagara2.

I added a hack to not do the relookup under the lock when create==0
and it now costs less than 300 cycles.

This is now a pretty common operation with the way we handle COW'd
metrics, so I think it's definitely worth optimizing.
-----------------

One solution is to use a seqlock instead of a spinlock to protect struct
inet_peer_base.

After a failed avl tree lookup, we can easily detect if a writer did
some changes during our lookup. Taking the lock and redo the lookup is
only necessary in this case.

Note: Add one private rcu_deref_locked() macro to place in one spot the
access to spinlock included in seqlock.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-04 14:33:59 -08:00
David S. Miller
ddd4aa424b inetpeer: Add redirect and PMTU discovery cached info.
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>
2011-02-10 13:29:30 -08:00
David S. Miller
7a71ed899e inetpeer: Abstract address representation further.
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>
2011-02-10 13:22:28 -08:00
David S. Miller
92d8682926 inetpeer: Move ICMP rate limiting state into inet_peer entries.
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>
2011-02-04 15:59:53 -08:00
David S. Miller
144001bddc inetpeer: Mark metrics as "new" in fresh inetpeer entries.
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>
2011-01-27 13:52:16 -08:00
David S. Miller
3408404a4c inetpeer: Use correct AVL tree base pointer in inet_getpeer().
Family was hard-coded to AF_INET but should be daddr->family.

This fixes crashes when unlinking ipv6 peer entries, since the
unlink code was looking up the base pointer properly.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 14:38:09 -08:00
David S. Miller
8790ca172a inetpeer: Kill use of inet_peer_address_t typedef.
They are verboten these days.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-01 17:28:18 -08:00
David S. Miller
b341936380 ipv6: Add infrastructure to bind inet_peer objects to routes.
They are only allowed on cached ipv6 routes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 12:27:11 -08:00
David S. Miller
021e929911 inetpeer: Add v6 peers tree, abstract root properly.
Add the ipv6 peer tree instance, and adapt remaining
direct references to 'v4_peers' as needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 12:12:23 -08:00
David S. Miller
0266304502 inetpeer: Abstract address comparisons.
Now v4 and v6 addresses will both work properly.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 12:08:53 -08:00
David S. Miller
b534ecf1cd inetpeer: Make inet_getpeer() take an inet_peer_adress_t pointer.
And make an inet_getpeer_v4() helper, update callers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 11:54:19 -08:00
David S. Miller
582a72da9a inetpeer: Introduce inet_peer_address_t.
Currently only the v4 aspect is used, but this will change.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 11:53:55 -08:00
David S. Miller
98158f5a85 inetpeer: Abstract out the tree root accesses.
Instead of directly accessing "peer", change to code to
operate using a "struct inet_peer_base *" pointer.

This will facilitate the addition of a seperate tree for
ipv6 peer entries.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 11:41:59 -08:00
Eric Dumazet
b914c4ea92 inetpeer: __rcu annotations
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>
2010-10-27 11:37:33 -07:00
Eric Dumazet
317fe0e6c5 inetpeer: restore small inet_peer structures
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>
2010-06-16 11:55:39 -07:00
Eric Dumazet
5f2f892095 inetpeer: do not use zero refcnt for freed entries
Followup of commit aa1039e73c (inetpeer: RCU conversion)

Unused inet_peer entries have a null refcnt.

Using atomic_inc_not_zero() in rcu lookups is not going to work for
them, and slow path is taken.

Fix this using -1 marker instead of 0 for deleted entries.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-15 21:47:39 -07:00
Eric Dumazet
aa1039e73c inetpeer: RCU conversion
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>
2010-06-15 14:23:38 -07:00
Eric Dumazet
d6cc1d642d inetpeer: various changes
Try to reduce cache line contentions in peer management, to reduce IP
defragmentation overhead.

- peer_fake_node is marked 'const' to make sure its not modified.
  (tested with CONFIG_DEBUG_RODATA=y)

- Group variables in two structures to reduce number of dirtied cache
lines. One named "peers" for avl tree root, its number of entries, and
associated lock. (candidate for RCU conversion)

- A second one named "unused_peers" for unused list and its lock

- Add a !list_empty() test in unlink_from_unused() to avoid taking lock
when entry is not unused.

- Use atomic_dec_and_lock() in inet_putpeer() to avoid taking lock in
some cases.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-14 23:13:08 -07:00
Eric Dumazet
2c1409a0a2 inetpeer: Optimize inet_getid()
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>
2009-11-13 20:46:58 -08:00
Jianjun Kong
d9319100c1 net: clean up net/ipv4/ah4.c esp4.c fib_semantics.c inet_connection_sock.c inetpeer.c ip_output.c
Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 00:23:42 -08:00
Adrian Bunk
0b04082995 net: remove CVS keywords
This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-11 21:00:38 -07:00
Pavel Emelyanov
d71209ded2 [INET]: Use list_head-s in inetpeer.c
The inetpeer.c tracks the LRU list of inet_perr-s, but makes
it by hands. Use the list_head-s for this.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-12 21:27:28 -08:00
Patrick McHardy
fc7b93800b [IPV4]: Fix inetpeer gcc-4.2 warnings
CC      net/ipv4/inetpeer.o
net/ipv4/inetpeer.c: In function 'unlink_from_pool':
net/ipv4/inetpeer.c:297: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c:297: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c: In function 'inet_getpeer':
net/ipv4/inetpeer.c:409: warning: the address of 'stack' will always evaluate as 'true'
net/ipv4/inetpeer.c:409: warning: the address of 'stack' will always evaluate as 'true'

"Fix" by checking for != NULL.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-20 19:39:17 -07:00
Paul Mundt
20c2df83d2 mm: Remove slab destructors from kmem_cache_create().
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-20 10:11:58 +09:00
Eric Dumazet
243bbcaa09 [IPV4]: Optimize inet_getpeer()
1) Some sysctl vars are declared __read_mostly

2) We can avoid updating stack[] when doing an AVL lookup only.

    lookup() macro is extended to receive a second parameter, that may be NULL
in case of a pure lookup (no need to save the AVL path). This removes
unnecessary instructions, because compiler knows if this _stack parameter is
NULL or not.

    text size of net/ipv4/inetpeer.o is 2063 bytes instead of 2107 on x86_64

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:49 -07:00