freebsd-nq/sys/net/netisr.h
Luigi Rizzo e4fc250c15 Device Polling code for -current.
Non-SMP, i386-only, no polling in the idle loop at the moment.

To use this code you must compile a kernel with

        options DEVICE_POLLING

and at runtime enable polling with

        sysctl kern.polling.enable=1

The percentage of CPU reserved to userland can be set with

        sysctl kern.polling.user_frac=NN (default is 50)

while the remainder is used by polling device drivers and netisr's.
These are the only two variables that you should need to touch. There
are a few more parameters in kern.polling but the default values
are adequate for all purposes. See the code in kern_poll.c for
more details on them.

Polling in the idle loop will be implemented shortly by introducing
a kernel thread which does the job. Until then, the amount of CPU
dedicated to polling will never exceed (100-user_frac).
The equivalent (actually, better) code for -stable is at

	http://info.iet.unipi.it/~luigi/polling/

and also supports polling in the idle loop.

NOTE to Alpha developers:
There is really nothing in this code that is i386-specific.
If you move the 2 lines supporting the new option from
sys/conf/{files,options}.i386 to sys/conf/{files,options} I am
pretty sure that this should work on the Alpha as well, just that
I do not have a suitable test box to try it. If someone feels like
trying it, I would appreciate it.

NOTE to other developers:
sure some things could be done better, and as always I am open to
constructive criticism, which a few of you have already given and
I greatly appreciated.
However, before proposing radical architectural changes, please
take some time to possibly try out this code, or at the very least
read the comments in kern_poll.c, especially re. the reason why I
am using a soft netisr and cannot (I believe) replace it with a
simple timeout.

Quick description of files touched by this commit:

sys/conf/files.i386
        new file kern/kern_poll.c
sys/conf/options.i386
        new option
sys/i386/i386/trap.c
        poll in trap (disabled by default)
sys/kern/kern_clock.c
        initialization and hardclock hooks.
sys/kern/kern_intr.c
        minor swi_net changes
sys/kern/kern_poll.c
        the bulk of the code.
sys/net/if.h
        new flag
sys/net/if_var.h
        declaration for functions used in device drivers.
sys/net/netisr.h
        NETISR_POLL
sys/dev/fxp/if_fxp.c
sys/dev/fxp/if_fxpvar.h
sys/pci/if_dc.c
sys/pci/if_dcreg.h
sys/pci/if_sis.c
sys/pci/if_sisreg.h
        device driver modifications
2001-12-14 17:56:12 +00:00

90 lines
3.4 KiB
C

/*
* Copyright (c) 1980, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)netisr.h 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#ifndef _NET_NETISR_H_
#define _NET_NETISR_H_
/*
* The networking code runs off software interrupts.
*
* You can switch into the network by doing splnet() and return by splx().
* The software interrupt level for the network is higher than the software
* level for the clock (so you can enter the network in routines called
* at timeout time).
*/
/*
* Each ``pup-level-1'' input queue has a bit in a ``netisr'' status
* word which is used to de-multiplex a single software
* interrupt used for scheduling the network code to calls
* on the lowest level routine of each protocol.
*/
#define NETISR_POLL 0 /* polling callback, must be first */
#define NETISR_IP 2 /* same as AF_INET */
#define NETISR_NS 6 /* same as AF_NS */
#define NETISR_ATALK 16 /* same as AF_APPLETALK */
#define NETISR_ARP 18 /* same as AF_LINK */
#define NETISR_IPX 23 /* same as AF_IPX */
#define NETISR_USB 25 /* USB soft interrupt */
#define NETISR_PPP 27 /* PPP soft interrupt */
#define NETISR_IPV6 28 /* same as AF_INET6 */
#define NETISR_NATM 29 /* same as AF_NATM */
#define NETISR_ATM 30 /* same as AF_ATM */
#define NETISR_NETGRAPH 31 /* same as AF_NETGRAPH */
#ifndef LOCORE
#ifdef _KERNEL
void legacy_setsoftnet __P((void));
extern volatile unsigned int netisr; /* scheduling bits for network */
extern void (*netisrs[32]) __P((void));
#define schednetisr(anisr) do { \
atomic_set_rel_int(&netisr, 1 << (anisr)); \
legacy_setsoftnet(); \
} while (0)
typedef void netisr_t __P((void));
int register_netisr __P((int, netisr_t *));
int unregister_netisr __P((int));
#endif
#endif
#endif