Commit graph

57 commits

Author SHA1 Message Date
Mark Johnston
8aa128800a netmap: Make memory pools NUMA-aware
Each netmap adapter associated with a physical adapter is attached to a
netmap memory pool.  contigmalloc() is used to allocate physically
contiguous memory for the pool, but ideally we would ensure that all
such memory is allocated from the NUMA domain local to the adapter.

Augment netmap's memory pools with a NUMA domain ID, similar to how
IOMMU groups are handled in the Linux port.  That is, when attaching to
a physical adapter, ensure that the associated memory pools are local to
the adapter's associated memory domain, creating new pools as needed.

Some types of ifnets do not have any defined NUMA affinity; in this case
the domain ID in question is the sentinel value -1.

Add a sysctl, dev.netmap.port_numa_affinity, which can be used to enable
the new behaviour.  Keep it disabled by now to avoid surprises in case
netmap applications are relying on zero-copy optimizations to forward
packets between ports belonging to different NUMA domains.

Reviewed by:	vmaffione
MFC after:	2 weeks
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D46666

(cherry picked from commit 1bae9dc584272dd75dc4e04cb5d73be0e9fb562a)
2024-11-04 08:08:06 +01:00
Mark Johnston
f36281617b netmap: Make the memory ops function pointer table const
No functional change intended.

Reviewed by:	vmaffione
MFC after:	2 weeks
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D46664

(cherry picked from commit 1ae4951ba7bb203d9a29892792960f0869759d35)
2024-10-11 11:02:10 +02:00
Franco Fichtner
36fb07bfef netmap: ring size limit not enough for multi-queue em(4)
Also mutes a spammy message.  Bravely going where no man
has gone before.  :)
2024-06-03 11:06:53 +02:00
Warner Losh
685dc743dc sys: Remove $FreeBSD$: one-line .c pattern
Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/
2023-08-16 11:54:36 -06:00
Warner Losh
4d846d260e spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with:		pfg
MFC After:		3 days
Sponsored by:		Netflix
2023-05-12 10:44:03 -06:00
Justin Hibbits
e330262f34 Mechanically convert netmap(4) to IfAPI
Reviewed by:	vmaffione, zlei
Sponsored by:	Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D37814
2023-02-14 10:21:19 -05:00
Vincenzo Maffione
09a1893398 netmap: fix refcount bug in netmap allocator
Symptom: when a single extmem memory region is provided to netmap
multiple times, for multiple interfaces, the memory region is
never released by netmap once all the existing file descriptors
are closed.

Fix the relevant condition in netmap_mem_drop(): release the memory
when the last user of netmap_adapter is gone, rather then when
the last user of netmap_mem_d is gone.

MFC after:	2 weeks
2022-03-06 16:39:16 +00:00
Vincenzo Maffione
3e3314a8b7 netmap: fix uint32_t overflow in pool size calculation
MFC after:	1 week
2021-09-26 13:56:33 +00:00
Vincenzo Maffione
98399ab06f netmap: import changes from upstream
- make sure rings are disabled during resets
 - introduce netmap_update_hostrings_mode(), with support
   for multiple host rings
 - always initialize ni_bufs_head in netmap_if
      ni_bufs_head was not properly initialized when no external buffers were
      requestedx and contained the ni_bufs_head from the last request. This
      was causing spurious buffer frees when alternating between apps that
      used external buffers and apps that did not use them.
 - check na validitity under lock on detach
 - netmap_mem: fix leak on error path
 - nm_dispatch: fix compilation on Raspberry Pi

MFC after:	2 weeks
2021-08-22 09:31:05 +00:00
Vincenzo Maffione
70275a6735 netmap: don't use linux type struct device *
Such type cannot be used in code that is in common between
FreeBSD and Linux. Use the FreeBSD type instead.

MFC after:	3 days
Reported by:	markj
Differential Revision:	https://reviews.freebsd.org/D29677
2021-04-11 21:13:01 +00:00
Vincenzo Maffione
45c67e8f6b netmap: several typo fixes
No functional changes intended.
2021-04-02 07:01:20 +00:00
Vincenzo Maffione
a6d768d845 netmap: add kernel support for the "offsets" feature
This feature enables applications to ask netmap to transmit or
receive packets starting at a user-specified offset from the
beginning of the netmap buffer. This is meant to ease those
packet manipulation operations such as pushing or popping packet
headers, that may be useful to implement software switches,
routers and other packet processors.
To use the feature, drivers (e.g., iflib, vtnet, etc.) must have
explicit support. This change does not add support for any driver,
but introduces the necessary kernel changes. However, offsets support
is already included for VALE ports and pipes.
2021-03-29 16:29:01 +00:00
Vincenzo Maffione
174f809da5 netmap: fix mutex double unlock bug
https://github.com/luigirizzo/netmap/pull/733

Submitted by:	 brian90013
MFC after:	3 days
2020-10-22 20:21:11 +00:00
Vincenzo Maffione
de27b30340 netmap_mem_unmap: fix NULL pointer dereference
MFC after:	3 days
2020-01-26 21:34:46 +00:00
Vincenzo Maffione
760fa2ab5d netmap: minor misc improvements
- use ring->head rather than ring->cur in lb(8)
 - use strlcat() rather than strncat()
 - fix bandwidth computation in pkt-gen(8)

MFC after:	1 week
2019-10-20 14:15:45 +00:00
Vincenzo Maffione
253b2ec199 netmap: import changes from upstream (SHA 137f537eae513)
- Rework option processing.
 - Use larger integers for memory size values in the
   memory management code.

MFC after:	2 weeks
2019-09-01 14:47:41 +00:00
Vincenzo Maffione
5d47236b18 netmap: Remove pointer leakage in netmap_mem2.c
PR:		238641
Submitted by:	Fuqian Huang <huangfq.daxian@gmail.com>
Reviewed by:	vmaffione
MFC after:	1 week
2019-07-04 21:31:49 +00:00
Vincenzo Maffione
d12354a56c netmap: add support for multiple host rings
Some applications forward from/to host rings most or all the
traffic received or sent on a physical interface. In this
cases it is desirable to have more than a pair of RX/TX host
rings, and use multiple threads to speed up forwarding.
This change adds support for multiple host rings. On registering
a netmap port, the user can specify the number of desired receive
and transmit host rings in the nr_host_tx_rings and nr_host_rx_rings
fields of the nmreq_register structure.

MFC after:	2 weeks
2019-03-18 12:22:23 +00:00
Vincenzo Maffione
75f4f3ed51 netmap: refactor logging macros and pipes
Changelist:
    - Replace ND, D and RD macros with nm_prdis, nm_prinf, nm_prerr
      and nm_prlim, to avoid possible naming conflicts.
    - Add netmap_krings_mode_commit() helper function and use that
      to reduce code duplication.
    - Refactor pipes control code to export some functions that
      can be reused by the veth driver (on Linux) and epair(4).
    - Add check to reject API requests with version less than 11.
    - Small code refactoring for the null adapter.

MFC after:	1 week
2019-02-05 12:10:48 +00:00
Vincenzo Maffione
b6e66be22b netmap: align codebase to the current upstream (760279cfb2730a585)
Changelist:
  - Replace netmap passthrough host support with a more general
    mechanism to call TXSYNC/RXSYNC from an in-kernel event-loop.
    No kernel threads are used to use this feature: the application
    is required to spawn a thread (or a process) and issue a
    SYNC_KLOOP_START (NIOCCTRL) command in the thread body. The
    kernel loop is executed by the ioctl implementation, which returns
    to userspace only when a different thread calls SYNC_KLOOP_STOP
    or the netmap file descriptor is closed.
  - Update the if_ptnet driver to cope with the new data structures,
    and prune all the obsolete ptnetmap code.
  - Add support for "null" netmap ports, useful to allocate netmap_if,
    netmap_ring and netmap buffers to be used by specialized applications
    (e.g. hypervisors). TXSYNC/RXSYNC on these ports have no effect.
  - Various fixes and code refactoring.

Sponsored by:	Sunny Valley Networks
Differential Revision:	https://reviews.freebsd.org/D18015
2018-12-05 11:57:16 +00:00
Vincenzo Maffione
2a7db7a63d netmap: align codebase to the current upstream (sha 8374e1a7e6941)
Changelist:
    - Move large parts of VALE code to a new file and header netmap_bdg.[ch].
      This is useful to reuse the code within upcoming projects.
    - Improvements and bug fixes to pipes and monitors.
    - Introduce nm_os_onattach(), nm_os_onenter() and nm_os_onexit() to
      handle differences between FreeBSD and Linux.
    - Introduce some new helper functions to handle more host rings and fake
      rings (netmap_all_rings(), netmap_real_rings(), ...)
    - Added new sysctl to enable/disable hw checksum in emulated netmap mode.
    - nm_inject: add support for NS_MOREFRAG

Approved by:	gnn (mentor)
Differential Revision:	https://reviews.freebsd.org/D17364
2018-10-23 08:55:16 +00:00
Matt Macy
cfa866f6a1 netmap: pull fix for 32-bit support from upstream
Approved by:	sbruno
2018-05-18 03:38:17 +00:00
Vincenzo Maffione
2ff91c175e netmap: align codebase to the current upstream (commit id 3fb001303718146)
Changelist:
    - Turn tx_rings and rx_rings arrays into arrays of pointers to kring
      structs. This patch includes fixes for ixv, ixl, ix, re, cxgbe, iflib,
      vtnet and ptnet drivers to cope with the change.
    - Generalize the nm_config() callback to accept a struct containing many
      parameters.
    - Introduce NKR_FAKERING to support buffers sharing (used for netmap
      pipes)
    - Improved API for external VALE modules.
    - Various bug fixes and improvements to the netmap memory allocator,
      including support for externally (userspace) allocated memory.
    - Refactoring of netmap pipes: now linked rings share the same netmap
      buffers, with a separate set of kring pointers (rhead, rcur, rtail).
      Buffer swapping does not need to happen anymore.
    - Large refactoring of the control API towards an extensible solution;
      the goal is to allow the addition of more commands and extension of
      existing ones (with new options) without the need of hacks or the
      risk of running out of configuration space.
      A new NIOCCTRL ioctl has been added to handle all the requests of the
      new control API, which cover all the functionalities so far supported.
      The netmap API bumps from 11 to 12 with this patch. Full backward
      compatibility is provided for the old control command (NIOCREGIF), by
      means of a new netmap_legacy module. Many parts of the old netmap.h
      header has now been moved to netmap_legacy.h (included by netmap.h).

Approved by:	hrs (mentor)
2018-04-12 07:20:50 +00:00
Vincenzo Maffione
4f80b14ce2 netmap: align codebase to upstream version v11.4
Changelist:
  - remove unused nkr_slot_flags
  - new nm_intr adapter callback to enable/disable interrupts
  - remove unused sysctls and document the other sysctls
  - new infrastructure to support NS_MOREFRAG for NIC ports
  - support for external memory allocator (for now linux-only),
    including linux-specific changes in common headers
  - optimizations within netmap pipes datapath
  - improvements on VALE control API
  - new nm_parse() helper function in netmap_user.h
  - various bug fixes and code clean up

Approved by:	hrs (mentor)
2018-04-09 09:24:26 +00:00
Pedro F. Giffuni
718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00
Luiz Otavio O Souza
4dd4446129 Restore the changes done in r313982: Replace zero with NULL for pointers.
Spotted by:	Harry Schmalzbauer
MFC after:	1 week
Sponsored by:	Rubicon Communications, LLC (Netgate)
2017-07-21 03:59:56 +00:00
Luiz Otavio O Souza
c3e9b4db8c Update the current version of netmap to bring it in sync with the github
version.

This commit contains mostly refactoring, a few fixes and minor added
functionality.

Submitted by:	Vincenzo Maffione <v.maffione at gmail.com>
Requested by:	many
Sponsored by:	Rubicon Communications, LLC (Netgate)
2017-06-12 22:53:18 +00:00
Pedro F. Giffuni
4d24901ac9 sys/dev: Replace zero with NULL for pointers.
Makes things easier to read, plus architectures may set NULL to something
different than zero.

Found with:	devel/coccinelle
MFC after:	3 weeks
2017-02-20 03:43:12 +00:00
Luigi Rizzo
844a6f0c53 Various fixes for ptnet/ptnetmap (passthrough of netmap ports). In detail:
- use PCI_VENDOR and PCI_DEVICE ids from a publicly allocated range
  (thanks to RedHat)
- export memory pool information through PCI registers
- improve mechanism for configuring passthrough on different hypervisors
Code is from Vincenzo Maffione as a follow up to his GSOC work.
2016-10-27 09:46:22 +00:00
Ed Maste
984ff0d910 netmap: fix kernel build on GCC-using architectures
GCC produced a multiple declaration warning from the
SYSCTL_DECL(_dev_netmap).
2016-10-21 13:51:47 +00:00
Luigi Rizzo
37e3a6d349 Import the current version of netmap, aligned with the one on github.
This commit, long overdue, contains contributions in the last 2 years
from Stefano Garzarella, Giuseppe Lettieri, Vincenzo Maffione, including:
+ fixes on monitor ports
+ the 'ptnet' virtual device driver, and ptnetmap backend, for
  high speed virtual passthrough on VMs (bhyve fixes in an upcoming commit)
+ improved emulated netmap mode
+ more robust error handling
+ removal of stale code
+ various fixes to code and documentation (some mixup between RX and TX
  parameters, and private and public variables)

We also include an additional tool, nmreplay, which is functionally
equivalent to tcpreplay but operating on netmap ports.
2016-10-16 14:13:32 +00:00
Jean-Sébastien Pédron
bd937497ea Consistently use device_t
Several files use the internal name of `struct device` instead of
`device_t` which is part of the public API. This patch changes all
`struct device *` to `device_t`.

The remaining occurrences of `struct device` are those referring to the
Linux or OpenBSD version of the structure, or the code is not built on
FreeBSD and it's unclear what to do.

Submitted by:	Matthew Macy <mmacy@nextbsd.org> (previous version)
Approved by:	emaste, jhibbits, sbruno
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D7447
2016-08-09 19:32:06 +00:00
Luigi Rizzo
847bf38369 Sync netmap sources with the version in our private tree.
This commit contains large contributions from Giuseppe Lettieri and
Stefano Garzarella, is partly supported by grants from Verisign and Cisco,
and brings in the following:

- fix zerocopy monitor ports and introduce copying monitor ports
  (the latter are lower performance but give access to all traffic
  in parallel with the application)

- exclusive open mode, useful to implement solutions that recover
  from crashes of the main netmap client (suggested by Patrick Kelsey)

- revised memory allocator in preparation for the 'passthrough mode'
  (ptnetmap) recently presented at bsdcan. ptnetmap is described in
        S. Garzarella, G. Lettieri, L. Rizzo;
        Virtual device passthrough for high speed VM networking,
        ACM/IEEE ANCS 2015, Oakland (CA) May 2015
        http://info.iet.unipi.it/~luigi/research.html

- fix rx CRC handing on ixl

- add module dependencies for netmap when building drivers as modules

- minor simplifications to device-specific routines (*txsync, *rxsync)

- general code cleanup (remove unused variables, introduce macros
  to access rings and remove duplicate code,

Applications do not need to be recompiled, unless of course
they want to use the new features (monitors and exclusive open).

Those willing to try this code on stable/10 can just update the
sys/dev/netmap/*, sys/net/netmap* with the version in HEAD
and apply the small patches to individual device drivers.

MFC after:	1 month
Sponsored by:	(partly) Verisign, Cisco
2015-07-10 05:51:36 +00:00
Patrick Kelsey
dd4fcbc594 When a netmap process terminates without the full set of buffers it
was granted via rings and ni_bufs_list_head represented in those rings
and lists (e.g., via SIGKILL), those buffers are no longer available
for subsequent users for the lifetime of the system. To mitigate this
resource leak, reset the allocator state when the last ref to that
allocator is released.

Note that this only recovers leaked resources for an allocator when
there are no longer any users of that allocator, so there remain
circumstances in which leaked allocator resources may not ever be
recovered - consider a set of multiple netmap processes that are all
using the same allocator (say, the global allocator) where members of
that set may be killed and restarted over time but at any given point
there is one member of that set running.

Based on intial work by adrian@.

Reviewed by: Giuseppe Lettieri (g.lettieri@iet.unipi.it), luigi
Approved by: jmallett (mentor)
MFC after: 1 week
Sponsored by: Norse Corp, Inc.
2015-05-15 15:36:57 +00:00
Luigi Rizzo
4bf50f18eb Update to the current version of netmap.
Mostly bugfixes or features developed in the past 6 months,
so this is a 10.1 candidate.

Basically no user API changes (some bugfixes in sys/net/netmap_user.h).

In detail:

1. netmap support for virtio-net, including in netmap mode.
  Under bhyve and with a netmap backend [2] we reach over 1Mpps
  with standard APIs (e.g. libpcap), and 5-8 Mpps in netmap mode.

2. (kernel) add support for multiple memory allocators, so we can
  better partition physical and virtual interfaces giving access
  to separate users. The most visible effect is one additional
  argument to the various kernel functions to compute buffer
  addresses. All netmap-supported drivers are affected, but changes
  are mechanical and trivial

3. (kernel) simplify the prototype for *txsync() and *rxsync()
  driver methods. All netmap drivers affected, changes mostly mechanical.

4. add support for netmap-monitor ports. Think of it as a mirroring
  port on a physical switch: a netmap monitor port replicates traffic
  present on the main port. Restrictions apply. Drive carefully.

5. if_lem.c: support for various paravirtualization features,
  experimental and disabled by default.
  Most of these are described in our ANCS'13 paper [1].
  Paravirtualized support in netmap mode is new, and beats the
  numbers in the paper by a large factor (under qemu-kvm,
  we measured gues-host throughput up to 10-12 Mpps).

A lot of refactoring and additional documentation in the files
in sys/dev/netmap, but apart from #2 and #3 above, almost nothing
of this stuff is visible to other kernel parts.

Example programs in tools/tools/netmap have been updated with bugfixes
and to support more of the existing features.

This is meant to go into 10.1 so we plan an MFC before the Aug.22 deadline.

A lot of this code has been contributed by my colleagues at UNIPI,
including Giuseppe Lettieri, Vincenzo Maffione, Stefano Garzarella.

MFC after:	3 days.
2014-08-16 15:00:01 +00:00
Luigi Rizzo
43ed1d3c76 whitespace change: remove trailing whitespace 2014-06-05 21:12:41 +00:00
Luigi Rizzo
f0ea3689a9 This new version of netmap brings you the following:
- netmap pipes, providing bidirectional blocking I/O while moving
  100+ Mpps between processes using shared memory channels
  (no mistake: over one hundred million. But mind you, i said
  *moving* not *processing*);

- kqueue support (BHyVe needs it);

- improved user library. Just the interface name lets you select a NIC,
  host port, VALE switch port, netmap pipe, and individual queues.
  The upcoming netmap-enabled libpcap will use this feature.

- optional extra buffers associated to netmap ports, for applications
  that need to buffer data yet don't want to make copies.

- segmentation offloading for the VALE switch, useful between VMs.

and a number of bug fixes and performance improvements.

My colleagues Giuseppe Lettieri and Vincenzo Maffione did a substantial
amount of work on these features so we owe them a big thanks.

There are some external repositories that can be of interest:

    https://code.google.com/p/netmap
        our public repository for netmap/VALE code, including
        linux versions and other stuff that does not belong here,
        such as python bindings.

    https://code.google.com/p/netmap-libpcap
        a clone of the libpcap repository with netmap support.
	With this any libpcap client has access to most netmap
	feature with no recompilation. E.g. tcpdump can filter
	packets at 10-15 Mpps.

    https://code.google.com/p/netmap-ipfw
        a userspace version of ipfw+dummynet which uses netmap
        to send/receive packets. Speed is up in the 7-10 Mpps
        range per core for simple rulesets.

Both netmap-libpcap and netmap-ipfw will be merged upstream at some
point, but while this happens it is useful to have access to them.

And yes, this code will be merged soon. It is infinitely better
than the version currently in 10 and 9.

MFC after:	3 days
2014-02-15 04:53:04 +00:00
Luigi Rizzo
f6c2a31f72 sync with our internal repo - small change in debugging messages 2014-01-10 16:00:27 +00:00
Luigi Rizzo
17885a7bfd It is 2014 and we have a new version of netmap.
Most relevant features:

- netmap emulation on any NIC, even those without native netmap support.

  On the ixgbe we have measured about 4Mpps/core/queue in this mode,
  which is still a lot more than with sockets/bpf.

- seamless interconnection of VALE switch, NICs and host stack.

  If you disable accelerations on your NIC (say em0)

        ifconfig em0 -txcsum -txcsum

  you can use the VALE switch to connect the NIC and the host stack:

        vale-ctl -h valeXX:em0

  allowing sharing the NIC with other netmap clients.

- THE USER API HAS SLIGHTLY CHANGED (head/cur/tail pointers
  instead of pointers/count as before). This was unavoidable to support,
  in the future, multiple threads operating on the same rings.
  Netmap clients require very small source code changes to compile again.
      On the plus side, the new API should be easier to understand
  and the internals are a lot simpler.

The manual page has been updated extensively to reflect the current
features and give some examples.

This is the result of work of several people including Giuseppe Lettieri,
Vincenzo Maffione, Michio Honda and myself, and has been financially
supported by EU projects CHANGE and OPENLAB, from NetApp University
Research Fund, NEC, and of course the Universita` di Pisa.
2014-01-06 12:53:15 +00:00
Luigi Rizzo
f9790aeb88 split netmap code according to functions:
- netmap.c		base code
- netmap_freebsd.c	FreeBSD-specific code
- netmap_generic.c	emulate netmap over standard drivers
- netmap_mbq.c		simple mbuf tailq
- netmap_mem2.c		memory management
- netmap_vale.c		VALE switch

simplify devce-specific code
2013-12-15 08:37:24 +00:00
Luigi Rizzo
ce3ee1e7c4 update to the latest netmap snapshot.
This includes the following:
- use separate memory regions for VALE ports
- locking fixes
- some simplifications in the NIC-specific routines
- performance improvements for the VALE switch
- some new features in the pkt-gen test program
- documentation updates

There are small API changes that require programs to be recompiled
(NETMAP_API has been bumped so you will detect old binaries at runtime).

In particular:
- struct netmap_slot now is 16 bytes to support an extra pointer,
  which may save one data copy when using VALE ports or VMs;
- the struct netmap_if has two extra fields;

MFC after:	3 days
2013-11-01 21:21:14 +00:00
Luigi Rizzo
ede69cff5b another minor bugfix in the memory allocator, this time in the free routine. 2013-05-10 08:46:10 +00:00
Luigi Rizzo
654ae8d68c remove trailing whitespace 2013-05-02 16:01:04 +00:00
Luigi Rizzo
28228e0816 whitespace - document alternative locking under linux 2013-04-29 19:30:35 +00:00
Luigi Rizzo
d4b42e0869 whitespace changes:
remove $Id$ lines, and add blank lines around some #if / #elif /#endif
2013-04-29 18:00:53 +00:00
Luigi Rizzo
2579e2d715 mostly whitespace changes:
- remove vestiges of the old memory allocator
- clean up some comments
2013-04-19 21:08:21 +00:00
Luigi Rizzo
aa76317cfc fix a bug in the computation of the userspace offset for a give netmap buffer.
Submitted by: Hugh Nhan
2013-04-15 11:49:16 +00:00
Luigi Rizzo
ae10d1afee control some debugging messages with dev.netmap.verbose
add infrastracture to adapt to changes in number of queues
and buffers at runtime
2013-01-23 03:51:47 +00:00
Ed Maste
d2b9185176 Use M_NOWAIT when calling malloc with a lock held.
The check for a NULL return was already in place so I assume this was just
an oversight.
2012-10-19 19:28:35 +00:00
Luigi Rizzo
8241616dc5 This is an import of code, mostly from Giuseppe Lettieri,
that revises the netmap memory allocator so that the
various parameters (number and size of buffers, rings, descriptors)
can be modified at runtime through sysctl variables.
The changes become effective when no netmap clients are active.

The API is mostly unchanged, although the NIOCUNREGIF ioctl now
does not bring the interface back to normal mode: and you
need to close the file descriptor for that.
This change was necessary to track who is using the mapped region,
and since it is a simplification of the API there was no
incentive in trying to preserve NIOCUNREGIF.
We will remove the ioctl from the kernel next time we need
a real API change (and version bump).

Among other things, buffer allocation when opening devices is
now much faster: it used to take O(N^2) time, now it is linear.

Submitted by:	Giuseppe Lettieri
2012-10-19 04:13:12 +00:00