Commit Graph

105 Commits

Author SHA1 Message Date
Navdeep Parhar
097f289f25 Fix for iWARP servers that listen on INADDR_ANY.
The iWARP Connection Manager (CM) on FreeBSD creates a TCP socket to
represent an iWARP endpoint when the connection is over TCP. For
servers the current approach is to invoke create_listen callback for
each iWARP RNIC registered with the CM. This doesn't work too well for
INADDR_ANY because a listen on any TCP socket already notifies all
hardware TOEs/RNICs of the new listener. This patch fixes the server
side of things for FreeBSD. We've tried to keep all these modifications
in the iWARP/TCP specific parts of the OFED infrastructure as much as
possible.

Submitted by:	Krishnamraju Eraparaju @ Chelsio (with design inputs from Steve Wise)
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D4801
2016-01-22 23:33:34 +00:00
Alexander V. Chernikov
8a9f7532b0 Convert cxgb/cxgbe to the new routing API.
Discussed with:		np
2016-01-07 08:07:17 +00:00
Gleb Smirnoff
0c39d38d21 Historically we have two fields in tcpcb to describe sender MSS: t_maxopd,
and t_maxseg. This dualism emerged with T/TCP, but was not properly cleaned
up after T/TCP removal. After all permutations over the years the result is
that t_maxopd stores a minimum of peer offered MSS and MTU reduced by minimum
protocol header. And t_maxseg stores (t_maxopd - TCPOLEN_TSTAMP_APPA) if
timestamps are in action, or is equal to t_maxopd otherwise. That's a very
rough estimate of MSS reduced by options length. Throughout the code it
was used in places, where preciseness was not important, like cwnd or
ssthresh calculations.

With this change:

- t_maxopd goes away.
- t_maxseg now stores MSS not adjusted by options.
- new function tcp_maxseg() is provided, that calculates MSS reduced by
  options length. The functions gives a better estimate, since it takes
  into account SACK state as well.

Reviewed by:	jtl
Differential Revision:	https://reviews.freebsd.org/D3593
2016-01-07 00:14:42 +00:00
Alexander V. Chernikov
4fb3a8208c Implement interface link header precomputation API.
Add if_requestencap() interface method which is capable of calculating
  various link headers for given interface. Right now there is support
  for INET/INET6/ARP llheader calculation (IFENCAP_LL type request).
  Other types are planned to support more complex calculation
  (L2 multipath lagg nexthops, tunnel encap nexthops, etc..).

Reshape 'struct route' to be able to pass additional data (with is length)
  to prepend to mbuf.

These two changes permits routing code to pass pre-calculated nexthop data
  (like L2 header for route w/gateway) down to the stack eliminating the
  need for other lookups. It also brings us closer to more complex scenarios
  like transparently handling MPLS nexthops and tunnel interfaces.
  Last, but not least, it removes layering violation introduced by flowtable
  code (ro_lle) and simplifies handling of existing if_output consumers.

ARP/ND changes:
Make arp/ndp stack pre-calculate link header upon installing/updating lle
  record. Interface link address change are handled by re-calculating
  headers for all lles based on if_lladdr event. After these changes,
  arpresolve()/nd6_resolve() returns full pre-calculated header for
  supported interfaces thus simplifying if_output().
Move these lookups to separate ether_resolve_addr() function which ether
  returs error or fully-prepared link header. Add <arp|nd6_>resolve_addr()
  compat versions to return link addresses instead of pre-calculated data.

BPF changes:
Raw bpf writes occupied _two_ cases: AF_UNSPEC and pseudo_AF_HDRCMPLT.
Despite the naming, both of there have ther header "complete". The only
  difference is that interface source mac has to be filled by OS for
  AF_UNSPEC (controlled via BIOCGHDRCMPLT). This logic has to stay inside
  BPF and not pollute if_output() routines. Convert BPF to pass prepend data
  via new 'struct route' mechanism. Note that it does not change
  non-optimized if_output(): ro_prepend handling is purely optional.
Side note: hackish pseudo_AF_HDRCMPLT is supported for ethernet and FDDI.
  It is not needed for ethernet anymore. The only remaining FDDI user is
  dev/pdq mostly untouched since 2007. FDDI support was eliminated from
  OpenBSD in 2013 (sys/net/if_fddisubr.c rev 1.65).

Flowtable changes:
  Flowtable violates layering by saving (and not correctly managing)
  rtes/lles. Instead of passing lle pointer, pass pointer to pre-calculated
  header data from that lle.

Differential Revision:	https://reviews.freebsd.org/D4102
2015-12-31 05:03:27 +00:00
Hans Petter Selasky
2da3897d01 Rename linuxapi[.ko] into linuxkpi[.ko], to reflect that it is a
kernel programming interface module, KPI, to avoid confusion with the
existing Linux userspace binary compatibility shims. Bump the
FreeBSD_version number.

Reviewed by:	np @
Suggested by:	dumbbell @
Sponsored by:	Mellanox Technologies
2015-10-22 09:50:45 +00:00
Julien Charbon
ff9b006d61 Decompose TCP INP_INFO lock to increase short-lived TCP connections scalability:
- The existing TCP INP_INFO lock continues to protect the global inpcb list
  stability during full list traversal (e.g. tcp_pcblist()).

- A new INP_LIST lock protects inpcb list actual modifications (inp allocation
  and free) and inpcb global counters.

It allows to use TCP INP_INFO_RLOCK lock in critical paths (e.g. tcp_input())
and INP_INFO_WLOCK only in occasional operations that walk all connections.

PR:			183659
Differential Revision:	https://reviews.freebsd.org/D2599
Reviewed by:		jhb, adrian
Tested by:		adrian, nitroboost-gmail.com
Sponsored by:		Verisign, Inc.
2015-08-03 12:13:54 +00:00
Dimitry Andric
4afafe0c86 Fix swapped copyin(9) arguments in cxgb's iwch_arm_cq() function.
Detected by clang 3.7.0 with the warning:

sys/dev/cxgb/ulp/iw_cxgb/iw_cxgb_provider.c:309:18: error: variable
'rptr' is uninitialized when used here [-Werror,-Wuninitialized]
                chp->cq.rptr = rptr;
                               ^~~~

MFC after:	1 week
2015-07-09 22:13:23 +00:00
Jung-uk Kim
fd90e2ed54 CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head.  However, it is continuously misused as the mpsafe argument
for callout_init(9).  Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision:	https://reviews.freebsd.org/D2613
Reviewed by:	jhb
MFC after:	2 weeks
2015-05-22 17:05:21 +00:00
Gleb Smirnoff
c578b6aca0 Provide a set of inline functions to manage simple mbuf(9) queues, based
on queue(3)'s STAILQ.  Utilize them in cxgb(4) and Xen, deleting home
grown implementations.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2015-02-19 01:19:42 +00:00
Hans Petter Selasky
b5c1e0cb8d Update the infiniband stack to Mellanox's OFED version 2.1.
Highlights:
 - Multiple verbs API updates
 - Support for RoCE, RDMA over ethernet

All hardware drivers depending on the common infiniband stack has been
updated aswell.

Discussed with:	np @
Sponsored by:	Mellanox Technologies
MFC after:	1 month
2015-02-17 08:40:27 +00:00
Hans Petter Selasky
d39d7c8636 Add missing linuxapi module dependencies and always use the FreeBSD
"MODULE_VERSION" macro definition. Remove the redefinition of the
"MODULE_VERSION" macro from the Linux kernel compatibility API.

MFC after:	1 month
Reported by:	np@
Sponsored by:	Mellanox Technologies
2015-01-19 21:53:00 +00:00
Robert Watson
fe522dc9e3 In mbuf_to_synq_entry(), use M_START() and M_SIZE() to calculate an offset
into mbuf storage, to reduce knowledge about mbuf/cluster layout in the
cxgb device driver.

Reviewed by:	np
Sponsored by:	EMC / Isilon Storage Division
2015-01-02 19:06:27 +00:00
Gleb Smirnoff
651e4e6a30 Merge from projects/sendfile: extend protocols API to support
sending not ready data:
o Add new flag to pru_send() flags - PRUS_NOTREADY.
o Add new protocol method pru_ready().

Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2014-11-30 13:24:21 +00:00
Gleb Smirnoff
cfa6009e36 In preparation of merging projects/sendfile, transform bare access to
sb_cc member of struct sockbuf to a couple of inline functions:

sbavail() and sbused()

Right now they are equal, but once notion of "not ready socket buffer data",
will be checked in, they are going to be different.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-12 09:57:15 +00:00
Hans Petter Selasky
af3b2549c4 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
Glen Barber
37a107a407 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
Hans Petter Selasky
3da1cf1e88 Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
Dimitry Andric
1e431cf636 In sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c, remove static functions
mk_cpl_barrier_ulp(), mk_get_tcb_ulp() and mk_set_tcb_field_ulp(), which
are all unused since r237263.

MFC after:	3 days
2013-12-25 22:49:54 +00:00
Gleb Smirnoff
c3322cb91c Include necessary headers that now are available due to pollution
via if_var.h.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-28 07:29:16 +00:00
Navdeep Parhar
721cdb1053 Add dependency on ibcore now that it has been modularized.
Approved by:	re (gjb)
2013-10-10 22:38:35 +00:00
Alfred Perlstein
c9f432b7ba Update OFED to Linux 3.7 and update Mellanox drivers.
Update the OFED Infiniband core to the version supplied in Linux
version 3.7.

The update to OFED is nearly all additional defines and functions
with the exception of the addition of additional parameters to
ib_register_device() and the reg_user_mr callback.

In addition the ibcore (Infiniband core) and ipoib (IP over Infiniband)
have both been made into completely loadable modules to facilitate
testing of the OFED stack in FreeBSD.

Finally the Mellanox Infiniband drivers are now updated to the
latest version shipping with Linux 3.7.

Submitted by: Mellanox FreeBSD driver team:
                Oded Shanoon (odeds mellanox.com),
                Meny Yossefi (menyy mellanox.com),
                Orit Moskovich (oritm mellanox.com)

Approved by: re
2013-09-29 00:35:03 +00:00
Navdeep Parhar
bb6a76ed22 Whitespace cleanup. 2013-08-23 18:45:39 +00:00
Ed Schouten
6b946662d9 Prefer __containerof() over __member2struct().
The former works better with qualifiers, but also properly type checks
the input pointer.
2012-10-19 13:26:40 +00:00
Kevin Lo
9823d52705 Revert previous commit...
Pointyhat to:	kevlo (myself)
2012-10-10 08:36:38 +00:00
Kevin Lo
a10cee30c9 Prefer NULL over 0 for pointers 2012-10-09 08:27:40 +00:00
Navdeep Parhar
87a74dd6e3 Deal with the case where a syncache entry added by the TOE driver is
evicted from the syncache but a later syncache_expand succeeds because
of syncookies.  The TOE driver has to resort to more direct means to
install its hooks in the socket in this case.
2012-08-21 22:23:17 +00:00
Navdeep Parhar
06fd9875aa Correctly handle the case where an inp has already been dropped by the time
the TOE driver reports that an active open failed.  toe_connect_failed is
supposed to handle this but it should be provided the inpcb instead of the
tcpcb which may no longer be around.
2012-08-21 18:09:33 +00:00
Dimitry Andric
25982a6e2d In cxgb(4), in function iwch_reregister_phys_mem(), initialize the
'npages' variable to zero, to avoid using it uninitialized in certain
cases.

Found by:	clang
Reviewed by:	np
MFC after:	1 week
2012-08-06 18:51:14 +00:00
Navdeep Parhar
09fe63205c - Updated TOE support in the kernel.
- Stateful TCP offload drivers for Terminator 3 and 4 (T3 and T4) ASICs.
  These are available as t3_tom and t4_tom modules that augment cxgb(4)
  and cxgbe(4) respectively.  The cxgb/cxgbe drivers continue to work as
  usual with or without these extra features.

- iWARP driver for Terminator 3 ASIC (kernel verbs).  T4 iWARP in the
  works and will follow soon.

Build-tested with make universe.

30s overview
============
What interfaces support TCP offload?  Look for TOE4 and/or TOE6 in the
capabilities of an interface:
# ifconfig -m | grep TOE

Enable/disable TCP offload on an interface (just like any other ifnet
capability):
# ifconfig cxgbe0 toe
# ifconfig cxgbe0 -toe

Which connections are offloaded?  Look for toe4 and/or toe6 in the
output of netstat and sockstat:
# netstat -np tcp | grep toe
# sockstat -46c | grep toe

Reviewed by:	bz, gnn
Sponsored by:	Chelsio communications.
MFC after:	~3 months (after 9.1, and after ensuring MFC is feasible)
2012-06-19 07:34:13 +00:00
Ed Schouten
6472ac3d8a Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
Matthew D Fleming
deceab8792 sysctl(9) cleanup checkpoint: amd64 GENERIC builds cleanly.
Commit the cxgb driver piece.
2011-01-12 19:53:44 +00:00
Alan Cox
82de724fe1 Introduce and use a new VM interface for temporarily pinning pages. This
new interface replaces the combined use of vm_fault_quick() and
pmap_extract_and_hold() throughout the kernel.

In collaboration with:	kib@
2010-12-25 21:26:56 +00:00
Alan Cox
c2f86e4192 The local variable "rv" is still required by vm_fault_hold_user_pages(). 2010-12-20 23:41:31 +00:00
Alan Cox
acd11c7499 Introduce vm_fault_hold() and use it to (1) eliminate a long-standing race
condition in proc_rwmem() and to (2) simplify the implementation of the
cxgb driver's vm_fault_hold_user_pages().  Specifically, in proc_rwmem()
the requested read or write could fail because the targeted page could be
reclaimed between the calls to vm_fault() and vm_page_hold().

In collaboration with:	kib@
MFC after:	6 weeks
2010-12-20 22:49:31 +00:00
Alan Cox
8c22654d7e Implement and use a single optimized function for unholding a set of pages.
Reviewed by:	kib@
2010-12-17 22:41:22 +00:00
Andriy Gapon
5579e006db fix incorrect use of atomic_set_xxx in cxgb
There is no need to use an atomic operation at structure initialization
time.
Note that the file changed is not connected to the build at this time.

Reviewed by:	jhb (general issue)
Approved by:	np
MFC after:	2 weeks
2010-12-11 10:14:08 +00:00
Alan Cox
69a990a144 Catch up with the page and page queues locking changes. 2010-06-18 23:14:16 +00:00
Navdeep Parhar
e83ec3e5c3 There is no need to test __FreeBSD_version for features that have
been around for a long time now (7.1-ish or even earlier); assume
they are present.  These includes MSI, TSO, LRO, VLAN, INTR_FILTERS,
FIRMWARE, etc.

Also, eliminate some dead code and clean up in other places as part
of this quick once-over.

MFC after:	1 week
2010-02-24 10:16:18 +00:00
Ulrich Spörlein
8fa03d08ca Fix common misspelling of hierarchy
Pointed out by:		bf1783 at gmail
Approved by:		np (cxgb), kientzle (tar, etc.), philip (mentor)
2010-02-20 10:19:19 +00:00
John Baldwin
43d9473499 - Rename the __tcpi_(snd|rcv)_mss fields of the tcp_info structure to remove
the leading underscores since they are now implemented.
- Implement the tcpi_rto and tcpi_last_data_recv fields in the tcp_info
  structure.

Reviewed by:	rwatson
MFC after:	2 weeks
2009-12-22 15:47:40 +00:00
Alan Cox
e2997fea72 Simplify the invocation of vm_fault(). Specifically, eliminate the flag
VM_FAULT_DIRTY.  The information provided by this flag can be trivially
inferred by vm_fault().

Discussed with:	kib
2009-11-27 20:24:11 +00:00
Robert Watson
315e3e38fa Many network stack subsystems use a single global data structure to hold
all pertinent statatistics for the subsystem.  These structures are
sometimes "borrowed" by kernel modules that require a place to store
statistics for similar events.

Add KPI accessor functions for statistics structures referenced by kernel
modules so that they no longer encode certain specifics of how the data
structures are named and stored.  This change is intended to make it
easier to move to per-CPU network stats following 8.0-RELEASE.

The following modules are affected by this change:

      if_bridge
      if_cxgb
      if_gif
      ip_mroute
      ipdivert
      pf

In practice, most of these statistics consumers should, in fact, maintain
their own statistics data structures rather than borrowing structures
from the base network stack.  However, that change is too agressive for
this point in the release cycle.

Reviewed by:	bz
Approved by:	re (kib)
2009-08-02 19:43:32 +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
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
Lawrence Stewart
5f1ff8136a Fix a buglet that slipped into r195654. My buildworld/buildkernel sanity
check missed this because cxgb's TOM is currently commented out of the build
system.

Submitted by:	Navdeep Parhar <np at FreeBSD dot org>
Approved by:	re (kensmith), kensmith (mentor temporarily unavailable)
2009-07-14 11:53:21 +00:00
Lawrence Stewart
237fbe0a1c Replace struct tcpopt with a proxy toeopt struct in the TOE driver interface to
the TCP syncache. This returns struct tcpopt to being private within the TCP
implementation, thus allowing it to be modified without ABI concerns.

The patch breaks the ABI. Bump __FreeBSD_version to 800103 accordingly. The cxgb
driver is the only TOE consumer affected by this change, and needs to be
recompiled along with the kernel.

Suggested by:	rwatson
Reviewed by:	rwatson, kmacy
Approved by:	re (kensmith), kensmith (mentor temporarily unavailable)
2009-07-13 11:51:02 +00:00
Bjoern A. Zeeb
5736e6fb9d After cleaning up rt_tables from vnet.h and cleaning up opt_route.h
a lot of files no longer need route.h either. Garbage collect them.
While here remove now unneeded vnet.h #includes as well.
2009-06-23 17:03:45 +00:00
Robert Watson
8896f83a58 Add a new function, ifa_ifwithaddr_check(), which rather than returning
a pointer to an ifaddr matching the passed socket address, returns a
boolean indicating whether one was present.  In the (near) future,
ifa_ifwithaddr() will return a referenced ifaddr rather than a raw
ifaddr pointer, and the new wrapper will allow callers that care only
about the boolean condition to avoid having to free that reference.

MFC after:	3 weeks
2009-06-22 10:59:34 +00:00
Bjoern A. Zeeb
8d8bc0182e After r193232 rt_tables in vnet.h are no longer indirectly dependent on
the ROUTETABLES kernel option thus there is no need to include opt_route.h
anymore in all consumers of vnet.h and no longer depend on it for module
builds.

Remove the hidden include in flowtable.h as well and leave the two
explicit #includes in ip_input.c and ip_output.c.
2009-06-08 19:57:35 +00:00
John Baldwin
74fb0ba732 Rework socket upcalls to close some races with setup/teardown of upcalls.
- Each socket upcall is now invoked with the appropriate socket buffer
  locked.  It is not permissible to call soisconnected() with this lock
  held; however, so socket upcalls now return an integer value.  The two
  possible values are SU_OK and SU_ISCONNECTED.  If an upcall returns
  SU_ISCONNECTED, then the soisconnected() will be invoked on the
  socket after the socket buffer lock is dropped.
- A new API is provided for setting and clearing socket upcalls.  The
  API consists of soupcall_set() and soupcall_clear().
- To simplify locking, each socket buffer now has a separate upcall.
- When a socket upcall returns SU_ISCONNECTED, the upcall is cleared from
  the receive socket buffer automatically.  Note that a SO_SND upcall
  should never return SU_ISCONNECTED.
- All this means that accept filters should now return SU_ISCONNECTED
  instead of calling soisconnected() directly.  They also no longer need
  to explicitly clear the upcall on the new socket.
- The HTTP accept filter still uses soupcall_set() to manage its internal
  state machine, but other accept filters no longer have any explicit
  knowlege of socket upcall internals aside from their return value.
- The various RPC client upcalls currently drop the socket buffer lock
  while invoking soreceive() as a temporary band-aid.  The plan for
  the future is to add a new flag to allow soreceive() to be called with
  the socket buffer locked.
- The AIO callback for socket I/O is now also invoked with the socket
  buffer locked.  Previously sowakeup() would drop the socket buffer
  lock only to call aio_swake() which immediately re-acquired the socket
  buffer lock for the duration of the function call.

Discussed with:	rwatson, rmacklem
2009-06-01 21:17:03 +00:00