Commit Graph

206 Commits

Author SHA1 Message Date
Gleb Smirnoff
5caf0d560d Fix the parse type for NGM_LISTTYPES.
Actually, text versions of generic commands are not used, since ngctl(8)
uses binary messages for them. And to request a text command one needs
a working ngctl(8). That's why the bug was never discovered. I'm pondering
on removing the text support for generic commands.

Found by:	dim with clang 3.4
2013-12-29 18:34:29 +00:00
Alexander V. Chernikov
d2fd078832 Improve locking model used to protect netgraph topology:
use rwlocks instead of mutexes on node traversal.

Reviewed by:	glebius
Tested by:	Eugene Grosbein <egrosbein@rdtc.ru>
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2013-10-15 17:44:35 +00:00
Craig Rodrigues
719fb72517 PR: 168520 170096
Submitted by: adrian, zec

Fix multiple kernel panics when VIMAGE is enabled in the kernel.
These fixes are based on patches submitted by Adrian Chadd and Marko Zec.

(1)  Set curthread->td_vnet to vnet0 in device_probe_and_attach() just before calling
     device_attach().  This fixes multiple VIMAGE related kernel panics
     when trying to attach Bluetooth or USB Ethernet devices because
     curthread->td_vnet is NULL.

(2)  Set curthread->td_vnet in if_detach().  This fixes kernel panics when detaching networking
     interfaces, especially USB Ethernet devices.

(3)  Use VNET_DOMAIN_SET() in ng_btsocket.c

(4)  In ng_unref_node() set curthread->td_vnet.  This fixes kernel panics
     when detaching Netgraph nodes.
2013-07-15 01:32:55 +00:00
Gabor Kovesdan
a2098fea6d - Correct mispellings of the word necessary
Submitted by:	Christoph Mallon <christoph.mallon@gmx.de> (via private mail)
2013-04-17 11:42:40 +00:00
Ryan Stone
3fabe28bdc Ensure that all cases that enqueue a netgraph item for delivery by a
ngthread properly set the item's depth to 1.  In particular, prior to this
change if ng_snd_item failed to acquire a lock on a node, the item's depth
would not be set at all.  This fix ensures that the error code from rcvmsg/
rcvdata is properly passed back to the apply callback.  For example, this
fixes a bug where an error from rcvmsg/rcvdata would not previously
propagate back to a libnetgraph consumer when the message was queued.

Reviewed by:	mav
MFC after:	1 month
Sponsored by:	Sandvine Incorporated
2012-09-27 20:12:51 +00:00
Gleb Smirnoff
77a117ca28 Revert r231829, that was my braino. 2012-02-22 09:08:51 +00:00
Gleb Smirnoff
687adb703d Refactor the name hash and the ID hash, that are used to address nodes:
- Make hash sizes growable, to satisfy users running large mpd
  installations, having thousands of nodes.
- NG_NAMEHASH() proved to give a very bad distribution in real life
  name sets, while generic hash32_str(name, HASHINIT) proved to give
  an even one, so you the latter for name hash.
- Do not store unnamed nodes in slot 0 of name hash, no reason for that.
- Use the ID hash in cases when we need to run through all nodes: the
  NGM_LISTNODES command and in the vnet_netgraph_uninit().
- Implement NGM_LISTNODES and NGM_LISTNAMES as separate code, the former
  iterates through the ID hash, and the latter through the name hash.
- Keep count of all nodes and of named nodes, so that we don't need
  to count nodes in NGM_LISTNODES and NGM_LISTNAMES. The counters are
  also used to estimate whether we need to grow hashes.
- Close a race between two threads running ng_name_node() assigning same
  name to different nodes.
2012-02-16 19:10:01 +00:00
Gleb Smirnoff
320d00eee8 Specify correct loading order for core of netgraph(4). 2012-02-16 18:54:44 +00:00
Gleb Smirnoff
04fdc6c689 Supply correct "how" argument to the uma_zcreate(). 2012-02-16 18:51:12 +00:00
Gleb Smirnoff
b99a737923 Fix includes list.
Submitted by:	bde
2012-02-15 15:54:57 +00:00
Gleb Smirnoff
923d1d7814 Trim double empty lines. 2012-02-15 15:06:03 +00:00
Gleb Smirnoff
3eb05c287a Remove testing stuff, reducing kernel memory footprint by 1 Kb.
Anyway, when we are building a LINT kernel, all these macros
are tested via nodes.
2012-02-15 14:56:18 +00:00
Gleb Smirnoff
c3189b3fb4 In ng_bypass() add more protection against potential race
with ng_rmnode() and its followers.
2012-02-15 14:29:23 +00:00
Gleb Smirnoff
19afcd9829 style(9): sort includes. 2012-02-15 14:26:50 +00:00
Gleb Smirnoff
c4282b741b Convert locks that protect name hash, ID hash and typelist from
mutex(9) to rwlock(9) based locks.

While here remove dropping lock when processing NGM_LISTNODES,
and NGM_LISTTYPES generic commands. We don't need to drop it
since memory allocation is done with M_NOWAIT.
2012-01-23 15:17:14 +00:00
Gleb Smirnoff
4bd1b55756 style(9), whitespace and spelling nits. 2011-12-30 15:41:28 +00:00
Ed Schouten
d745c852be Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.
This means that their use is restricted to a single C file.
2011-11-07 06:44:47 +00:00
Max Khon
707d205808 Constify "address" argument of ng_address_path(). 2011-11-06 05:20:27 +00:00
Gleb Smirnoff
e5fe87b387 - If KDB & NETGRAPH_DEBUG are on, print traces on discovered failed
invariants.
- Reduce tautology in NETGRAPH_DEBUG output.
2011-10-27 09:43:25 +00:00
Gleb Smirnoff
3fbdf77459 - Use refcount(9) API to manage node and hook refcounting.
- Make ng_unref_node() void, since caller shouldn't be
  interested in whether node is valid after call or not,
  since it can't be guaranteed to be valid. [1]

Ok from:	julian [1]
2011-07-04 07:03:44 +00:00
Gleb Smirnoff
5633ca7116 Fix error where error variable was assigned result of comparison,
instead of function return value.

Submitted by:	Przemyslaw Frasunek <przemyslaw frasunek.com>
MFC after:	4 days
2011-04-17 16:31:21 +00:00
Gleb Smirnoff
a7da736a64 Improve locking of creating and dropping links in the graph, acquiring
the topology mutex in the following functions, that manipulate pointers
to peer nodes:

- ng_bypass()
- ng_path2noderef() when switching to the next node in sequence.
  Rewrite the function a bit.
- ng_address_hook()
- ng_address_path()

This patch improves stability of large mpd5 installations.
2011-03-21 14:18:40 +00:00
Dimitry Andric
3e288e6238 After some off-list discussion, revert a number of changes to the
DPCPU_DEFINE and VNET_DEFINE macros, as these cause problems for various
people working on the affected files.  A better long-term solution is
still being considered.  This reversal may give some modules empty
set_pcpu or set_vnet sections, but these are harmless.

Changes reverted:

------------------------------------------------------------------------
r215318 | dim | 2010-11-14 21:40:55 +0100 (Sun, 14 Nov 2010) | 4 lines

Instead of unconditionally emitting .globl's for the __start_set_xxx and
__stop_set_xxx symbols, only emit them when the set_vnet or set_pcpu
sections are actually defined.

------------------------------------------------------------------------
r215317 | dim | 2010-11-14 21:38:11 +0100 (Sun, 14 Nov 2010) | 3 lines

Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.

------------------------------------------------------------------------
r215316 | dim | 2010-11-14 21:23:02 +0100 (Sun, 14 Nov 2010) | 2 lines

Add macros to define static instances of VNET_DEFINE and DPCPU_DEFINE.
2010-11-22 19:32:54 +00:00
Dimitry Andric
31c6a0037e Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.
2010-11-14 20:38:11 +00:00
Marko Zec
98a5a343e3 Increase the target buffer for performing NGM_ASCII2BINARY conversion
from 2000 bytes to 20 Kbytes, which now matches the buffer size used for
NGM_BINARY2ASCII conversions.

The aim of this change is to allow for bigger binary structures to be
managed via netgraph ASCII messages, until we come up with an API
improvement which would get rid of such arbitrary hardcoded limits.

MFC after:	3 days
2010-05-13 16:48:28 +00:00
Marko Zec
a3f93b7269 When destroying a vnet, shut down all netgraph nodes tied to that vnet
before proceeding with dismantling other protocol domains.

This change only affects options VIMAGE builds.

Reviewed by:	julian, bz
MFC after:	3 days
2010-05-03 16:08:24 +00:00
Antoine Brodin
13e403fdea (S)LIST_HEAD_INITIALIZER takes a (S)LIST_HEAD as an argument.
Fix some wrong usages.
Note: this does not affect generated binaries as this argument is not used.

PR:		137213
Submitted by:	Eygene Ryabinkin (initial version)
MFC after:	1 month
2009-12-28 22:56:30 +00:00
Robert Watson
530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00
Robert Watson
d0728d7174 Introduce and use a sysinit-based initialization scheme for virtual
network stacks, VNET_SYSINIT:

- Add VNET_SYSINIT and VNET_SYSUNINIT macros to declare events that will
  occur each time a network stack is instantiated and destroyed.  In the
  !VIMAGE case, these are simply mapped into regular SYSINIT/SYSUNINIT.
  For the VIMAGE case, we instead use SYSINIT's to track their order and
  properties on registration, using them for each vnet when created/
  destroyed, or immediately on module load for already-started vnets.
- Remove vnet_modinfo mechanism that existed to serve this purpose
  previously, as well as its dependency scheme: we now just use the
  SYSINIT ordering scheme.
- Implement VNET_DOMAIN_SET() to allow protocol domains to declare that
  they want init functions to be called for each virtual network stack
  rather than just once at boot, compiling down to DOMAIN_SET() in the
  non-VIMAGE case.
- Walk all virtualized kernel subsystems and make use of these instead
  of modinfo or DOMAIN_SET() for init/uninit events.  In some cases,
  convert modular components from using modevent to using sysinit (where
  appropriate).  In some cases, do minor rejuggling of SYSINIT ordering
  to make room for or better manage events.

Portions submitted by:	jhb (VNET_SYSINIT), bz (cleanup)
Discussed with:		jhb, bz, julian, zec
Reviewed by:		bz
Approved by:		re (VIMAGE blanket)
2009-07-23 20:46:49 +00:00
Robert Watson
1e77c1056a Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used.  Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with:	bz, julian
Reviewed by:	bz
Approved by:	re (kensmith, kib)
2009-07-16 21:13:04 +00:00
Robert Watson
eddfbb763d Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00
Marko Zec
f089869fa5 Introduce a mechanism for detecting calls from outbound path of the
network stack when reentering the inbound path from netgraph, and
force queueing of mbufs at the outbound netgraph node.

The mechanism relies on two components.  First, in netgraph nodes
where outbound path of the network stack calls into netgraph, the
current thread has to be appropriately marked using the new
NG_OUTBOUND_THREAD_REF() macro before proceeding to call further
into the netgraph topology, and unmarked using the
NG_OUTBOUND_THREAD_UNREF() macro before returning to the caller.
Second, netgraph nodes which can potentially reenter the network
stack in the inbound path have to mark their inbound hooks using
NG_HOOK_SET_TO_INBOUND() macro.  The netgraph framework will then
detect when there is a danger of a call graph looping back from
outbound to inbound path via netgraph, and defer handing off the
mbufs to the "inbound" node to a worker thread with a clean stack.

In this first pass only the most obvious netgraph nodes have been
updated to ensure no outbound to inbound calls can occur.  Nodes
such as ng_ipfw, ng_gif etc. should be further examined whether a
potential for outbound to inbound call looping exists.

This commit changes the layout of struct thread, but due to
__FreeBSD_version number shortage a version bump has been omitted
at this time, nevertheless kernel and modules have to be rebuilt.

Reviewed by:	julian, rwatson, bz
Approved by:	julian (mentor)
2009-06-11 16:50:49 +00:00
Marko Zec
bc29160df3 Introduce an infrastructure for dismantling vnet instances.
Vnet modules and protocol domains may now register destructor
functions to clean up and release per-module state.  The destructor
mechanisms can be triggered by invoking "vimage -d", or a future
equivalent command which will be provided via the new jail framework.

While this patch introduces numerous placeholder destructor functions,
many of those are currently incomplete, thus leaking memory or (even
worse) failing to stop all running timers.  Many of such issues are
already known and will be incrementaly fixed over the next weeks in
smaller incremental commits.

Apart from introducing new fields in structs ifnet, domain, protosw
and vnet_net, which requires the kernel and modules to be rebuilt, this
change should have no impact on nooptions VIMAGE builds, since vnet
destructors can only be called in VIMAGE kernels.  Moreover,
destructor functions should be in general compiled in only in
options VIMAGE builds, except for kernel modules which can be safely
kldunloaded at run time.

Bump __FreeBSD_version to 800097.
Reviewed by:	bz, julian
Approved by:	rwatson, kib (re), julian (mentor)
2009-06-08 17:15:40 +00:00
Marko Zec
a40b78741b Unbreak LINT build, caused by a change in struct ng_node layout introduced
with r191816, which become uncovered only with NETGRAPH_DEBUG defined.

NOT approved by mentor (julian) due to emergency.
2009-05-05 16:26:06 +00:00
Marko Zec
aef8f3445b In preparation to make options VIMAGE operational, where needed,
initialize / release netgraph related state in iattach() / idetach()
functions called via the vnet module registration / initialization
framework, instead of initialization / cleanups being done in
mod_event handlers.

While here, introduce a crude hack aimed at preventing ng_ether to
autoattach to ng_eiface ifnets, which are also netgraph nodes already.

Reviewed by:	bz
Approved by:	julian (mentor)
2009-04-26 07:14:50 +00:00
Alexander Motin
f2fbb83858 To avoid one doubtless netgraph SMP scalability limitation point, switch
node queues processing from single swi:net thread to several specialized
threads.

Reviewed by:	julian
Tested with:	Netperf Cluster
2008-12-14 20:15:30 +00:00
Alexander Motin
15cea89fab Revert rev. 183277:
Remove ng_rmnode_flags() function.
ng_rmnode_self() was made to be called only while having node locked.
When node is properly locked, any function call sent to it will always be
queued. So turning ng_rmnode_self() into the ng_rmnode_flags() is not just
meaningless, but incorrent, as it violates node locking when called outside.

No objections:	julian, thompsa
2008-12-13 22:26:24 +00:00
Marko Zec
385195c062 Conditionally compile out V_ globals while instantiating the appropriate
container structures, depending on VIMAGE_GLOBALS compile time option.

Make VIMAGE_GLOBALS a new compile-time option, which by default will not
be defined, resulting in instatiations of global variables selected for
V_irtualization (enclosed in #ifdef VIMAGE_GLOBALS blocks) to be
effectively compiled out.  Instantiate new global container structures
to hold V_irtualized variables: vnet_net_0, vnet_inet_0, vnet_inet6_0,
vnet_ipsec_0, vnet_netgraph_0, and vnet_gif_0.

Update the VSYM() macro so that depending on VIMAGE_GLOBALS the V_
macros resolve either to the original globals, or to fields inside
container structures, i.e. effectively

#ifdef VIMAGE_GLOBALS
#define V_rt_tables rt_tables
#else
#define V_rt_tables vnet_net_0._rt_tables
#endif

Update SYSCTL_V_*() macros to operate either on globals or on fields
inside container structs.

Extend the internal kldsym() lookups with the ability to resolve
selected fields inside the virtualization container structs.  This
applies only to the fields which are explicitly registered for kldsym()
visibility via VNET_MOD_DECLARE() and vnet_mod_register(), currently
this is done only in sys/net/if.c.

Fix a few broken instances of MODULE_GLOBAL() macro use in SCTP code,
and modify the MODULE_GLOBAL() macro to resolve to V_ macros, which in
turn result in proper code being generated depending on VIMAGE_GLOBALS.

De-virtualize local static variables in sys/contrib/pf/net/pf_subr.c
which were prematurely V_irtualized by automated V_ prepending scripts
during earlier merging steps.  PF virtualization will be done
separately, most probably after next PF import.

Convert a few variable initializations at instantiation to
initialization in init functions, most notably in ipfw.  Also convert
TUNABLE_INT() initializers for V_ variables to TUNABLE_FETCH_INT() in
initializer functions.

Discussed at:	devsummit Strassburg
Reviewed by:	bz, julian
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-12-10 23:12:39 +00:00
Marko Zec
f02493cbbd Unhide declarations of network stack virtualization structs from
underneath #ifdef VIMAGE blocks.

This change introduces some churn in #include ordering and nesting
throughout the network stack and drivers but is not expected to cause
any additional issues.

In the next step this will allow us to instantiate the virtualization
container structures and switch from using global variables to their
"containerized" counterparts.

Reviewed by:	bz, julian
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-11-28 23:30:51 +00:00
Alexander Motin
9bd352d6fd Remove unneeded NULL check. At first msg can't be null here and and at second
NG_FREE_MSG() also checks it.

Found with:	Coverity Prevent(tm)
2008-11-22 16:03:18 +00:00
Dag-Erling Smørgrav
1ede983cc9 Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
Marko Zec
8b615593fc Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
Andrew Thompson
89ac5af9c1 Add ng_rmnode_flags() so the caller can pass NG_QUEUE and have the node
destroyed asynchronously due to locking or other constraints.

Reviewed by:	julian
2008-09-22 19:28:18 +00:00
Alexander Motin
74c9119d4a We can't implicitly trust the hook on NGQF_FN/NGQF_FN2 processing in
ng_apply_item(). There are possible (and I have got one) use-after-free
class panics because of it.

If hook is specified, require it to be valid at the apply time. The only
exceptions are the internal ng_con_part2(), ng_con_part3() and
ng_rmhook_part2() functions which are specially made to work with invalid
hooks.
2008-09-13 09:17:02 +00:00
Julian Elischer
ac957cd271 A bunch of formatting fixes brough to light by, or created by the Vimage commit
a few days ago.
2008-08-20 01:05:56 +00:00
Bjoern A. Zeeb
603724d3ab Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from:	//depot/projects/vimage-commit2/...
Reviewed by:	brooks, des, ed, mav, julian,
		jamie, kris, rwatson, zec, ...
		(various people I forgot, different versions)
		md5 (with a bit of help)
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
X-MFC after:	never
V_Commit_Message_Reviewed_By:	more people than the patch
2008-08-17 23:27:27 +00:00
Robert Watson
59dd72d040 Remove NETISR_MPSAFE, which allows specific netisr handlers to be directly
dispatched without Giant, and add NETISR_FORCEQUEUE, which allows specific
netisr handlers to always be dispatched via a queue (deferred).  Mark the
usb and if_ppp netisr handlers as NETISR_FORCEQUEUE, and explicitly
acquire Giant in those handlers.

Previously, any netisr handler not marked NETISR_MPSAFE would necessarily
run deferred and with Giant acquired.  This change removes Giant
scaffolding from the netisr infrastructure, but NETISR_FORCEQUEUE allows
non-MPSAFE handlers to continue to force deferred dispatch so as to avoid
lock order reversals between their acqusition of Giant and any calling
context.

It is likely we will be able to remove NETISR_FORCEQUEUE once
IFF_NEEDSGIANT is removed, as non-MPSAFE usb and if_ppp drivers will no
longer be supported.

Reviewed by:	bz
MFC after:	1 month
X-MFC note:	We can't remove NETISR_MPSAFE from stable/7 for KPI reasons,
		but the rest can go back.
2008-07-04 00:21:38 +00:00
Alexander Motin
a04e98468d ng_address_hook() microoptimization. Use local variables as they should be.
It helps compiller to avoid some extra memory accesses.
2008-04-19 05:30:49 +00:00
Alexander Motin
6aa6d011e4 Use separate UMA zone for data items allocation. It is a partial
rev. 1.149 rework.
It allows to save several percents of CPU time on SMP by using UMA's
internal per-CPU allocation limits instead of own global variable
each time updated with atomics.

Tested with:    Netperf cluster
2008-04-16 19:52:29 +00:00
Alexander Motin
9852972bb5 Several changes breaking netgraph module ABI collected together:
- reorder structures fields (XX_refs) a bit to group fields modified
   same time together. According to my tests it gives up to 10%
   SMP performance benefit on real workload due to reduced inter-CPU
   cache trashing.
 - change q_flags from long to int as long is not really needed there and
   it's usage with atomics is argued by some people.
 - move NGF_WORKQ flag into the separate field q_flags2 as it protected by
   queue mutex instead of node writer protection used by the rest of flags.
 - move nd_work queue entry to ng_queue structure to which it is more
   related and make it STAILQ instead of TAILQ as now it is a classic FIFO.
 - remove q_node pointer from ng_queue structure as it is not really needed.
 - reimplement item queue using STAILQ instead of own equal implementation.
   As soon as BT subsystem has own item queues using ng_item.el_next update
   it also.
 - change depth field in ng_item from uintptr_t to u_int. It was made
   uintptr_t to keep ABI compatibility.

Reviewed by:	julian, emax
Tested with:	Netperf cluster
2008-04-15 21:15:32 +00:00