Commit Graph

25 Commits

Author SHA1 Message Date
Gleb Smirnoff
f0796cd26c - Don't pollute opt_global.h with DEVICE_POLLING and introduce
opt_device_polling.h
- Include opt_device_polling.h into appropriate files.
- Embrace with HAVE_KERNEL_OPTION_HEADERS the include in the files that
  can be compiled as loadable modules.

Reviewed by:	bde
2005-10-05 10:09:17 +00:00
Gleb Smirnoff
e113edf30a o Move a lot of parameter checking from netisr_poll() to
dedicated sysctl handlers. Protect manipulations with
  poll_mtx. The affected sysctls are:
  - kern.polling.burst_max
  - kern.polling.each_burst
  - kern.polling.user_frac
  - kern.polling.reg_frac
o Use CTLFLAG_RD on MIBs that supposed to be read-only.
o u_int32t -> uint32_t
o Remove unneeded locking from poll_switch().
2005-10-03 14:15:26 +00:00
Gleb Smirnoff
4092996774 Big polling(4) cleanup.
o Axe poll in trap.

o Axe IFF_POLLING flag from if_flags.

o Rework revision 1.21 (Giant removal), in such a way that
  poll_mtx is not dropped during call to polling handler.
  This fixes problem with idle polling.

o Make registration and deregistration from polling in a
  functional way, insted of next tick/interrupt.

o Obsolete kern.polling.enable. Polling is turned on/off
  with ifconfig.

Detailed kern_poll.c changes:
  - Remove polling handler flags, introduced in 1.21. The are not
    needed now.
  - Forget and do not check if_flags, if_capenable and if_drv_flags.
  - Call all registered polling handlers unconditionally.
  - Do not drop poll_mtx, when entering polling handlers.
  - In ether_poll() NET_LOCK_GIANT prior to locking poll_mtx.
  - In netisr_poll() axe the block, where polling code asks drivers
    to unregister.
  - In netisr_poll() and ether_poll() do polling always, if any
    handlers are present.
  - In ether_poll_[de]register() remove a lot of error hiding code. Assert
    that arguments are correct, instead.
  - In ether_poll_[de]register() use standard return values in case of
    error or success.
  - Introduce poll_switch() that is a sysctl handler for kern.polling.enable.
    poll_switch() goes through interface list and enabled/disables polling.
    A message that kern.polling.enable is deprecated is printed.

Detailed driver changes:
  - On attach driver announces IFCAP_POLLING in if_capabilities, but
    not in if_capenable.
  - On detach driver calls ether_poll_deregister() if polling is enabled.
  - In polling handler driver obtains its lock and checks IFF_DRV_RUNNING
    flag. If there is no, then unlocks and returns.
  - In ioctl handler driver checks for IFCAP_POLLING flag requested to
    be set or cleared. Driver first calls ether_poll_[de]register(), then
    obtains driver lock and [dis/en]ables interrupts.
  - In interrupt handler driver checks IFCAP_POLLING flag in if_capenable.
    If present, then returns.This is important to protect from spurious
    interrupts.

Reviewed by:	ru, sam, jhb
2005-10-01 18:56:19 +00:00
Gleb Smirnoff
f46ab10c02 Document flags of a pollrec. 2005-09-06 11:09:18 +00:00
Gleb Smirnoff
16901c0186 Remove Giant mutex from polling(4) and use a separate poll_mtx(4)
instead. Detailed changelist:

o Add flags field to struct pollrec, to indicate that
  are particular entry is being worked on.
o Define a macro PR_VALID() to check that a pollrec
  is valid and pollable.
o Mark ISRs as mpsafe.

o ether_poll()
  - Acquire poll_mtx while traversing pollrec array.
  - Skip pollrecs, that are being worked on.
  - Conditionally acquire Giant when entering handler.

o netisr_pollmore()
  - Conditionally assert Giant.
  - Acquire poll_mtx while working with statistics.

o netisr_poll()
  - Conditionally assert Giant.
  - Acquire poll_mtx while working with statistics
    and traversing pollrec array.

o ether_poll_register(), ether_poll_deregister()
  - Conditionally assert Giant.
  - Acquire poll_mtx while working with pollrec array.

o poll_idle()
  - Remove all strange manipulations with Giant.

In collaboration with:	ru, pjd
In collaboration with:	Oleg Bulyzhin <oleg rinet.ru>
In collaboration with:	dima <_pppp mail.ru>
2005-09-05 16:02:11 +00:00
Robert Watson
13f4c340ae Propagate rename of IFF_OACTIVE and IFF_RUNNING to IFF_DRV_OACTIVE and
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags.  Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags.  This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.

Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.

Reviewed by:	pjd, bz
MFC after:	7 days
2005-08-09 10:20:02 +00:00
Tom Rhodes
183a16a3ec Remove recently added note about DEVICE_POLLING not working with SMP.
Remove warning from kern_poll.c to allow DEVICE_POLLING to be built with SMP.

Discussed with:	ru, glebius
2005-02-25 22:07:51 +00:00
John Baldwin
b5cbda5055 Add a NULL param to an mi_switch() that I missed.
Reported by:	Jung-uk Kim jkim at niksun dot com
2004-07-03 02:38:03 +00:00
Ruslan Ermilov
61f7581d08 Ensure that the poll_burst <= poll_burst_max constraint really holds.
Reviewed by:	luigi
2004-04-15 07:38:44 +00:00
Jeff Roberson
29bcc4514f - Add a flags parameter to mi_switch. The value of flags may be SW_VOL or
SW_INVOL.  Assert that one of these is set in mi_switch() and propery
   adjust the rusage statistics.  This is to simplify the large number of
   users of this interface which were previously all required to adjust the
   proper counter prior to calling mi_switch().  This also facilitates more
   switch and locking optimizations.
 - Change all callers of mi_switch() to pass the appropriate paramter and
   remove direct references to the process statistics.
2004-01-25 03:54:52 +00:00
Sam Leffler
7902224c6b o add a flags parameter to netisr_register that is used to specify
whether or not the isr needs to hold Giant when running; Giant-less
  operation is also controlled by the setting of debug_mpsafenet
o mark all netisr's except NETISR_IP as needing Giant
o add a GIANT_REQUIRED assertion to the top of netisr's that need Giant
o pickup Giant (when debug_mpsafenet is 1) inside ip_input before
  calling up with a packet
o change netisr handling so swi_net runs w/o Giant; instead we grab
  Giant before invoking handlers based on whether the handler needs Giant
o change netisr handling so that netisr's that are marked MPSAFE may
  have multiple instances active at a time
o add netisr statistics for packets dropped because the isr is inactive

Supported by:	FreeBSD Foundation
2003-11-08 22:28:40 +00:00
Sam Leffler
6c24056459 revert default for idle polling to zero until we can resolve the
livelock problem
2003-10-20 21:14:24 +00:00
Sam Leffler
bd19669855 Change default for kern.polling.idle_poll back to 1. This was set to 0
because Luigi observed livelock but in recent testing it did not occur
so I'm re-enabling it by default.

Reviewed by:	luigi
2003-10-14 18:39:36 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Jonathan Lemon
1cafed3941 Update netisr handling; Each SWI now registers its queue, and all queue
drain routines are done by swi_net, which allows for better queue control
at some future point.  Packets may also be directly dispatched to a netisr
instead of queued, this may be of interest at some installations, but
currently defaults to off.

Reviewed by: hsu, silby, jayanth, sam
Sponsored by: DARPA, NAI Labs
2003-03-04 23:19:55 +00:00
Maxim Sobolev
62f7648682 Increase size of ifnet.if_flags from 16 bits (short) to 32 bits (int). To avoid
breaking application ABI use unused ifreq.ifru_flags[1] for upper 16 bits in
SIOCSIFFLAGS and SIOCGIFFLAGS ioctl's.

Reviewed by:	-hackers, -net
2002-08-18 07:05:00 +00:00
Luigi Rizzo
fc1c73c21a Temporarily disable polling when no processes are active, while I
investigate the problem described below.

I am seeing some strange livelock on recent -current sources with
a slow box under heavy load, which disappears with this change.
This might suggest some kind of problem (either insufficient locking,
or mishandling of priorities) in the poll_idle thread.
2002-08-04 21:00:49 +00:00
Julian Elischer
e602ba25fd Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by:	Almost everyone who counts
	(at various times, peter, jhb, matt, alfred, mini, bernd,
	and a cast of thousands)

	NOTE: this is still Beta code, and contains lots of debugging stuff.
	expect slight instability in signals..
2002-06-29 17:26:22 +00:00
Luigi Rizzo
d26d355f0e Remove a printf and add a comment on an assumption that could be
occasionally violated by device drivers.
2002-06-27 23:23:04 +00:00
Luigi Rizzo
2dbd9d5bc3 Make the DEVICE_POLLING code compile with -Werror and in LINT 2002-03-09 08:02:52 +00:00
Luigi Rizzo
e522304423 Make this compile after changes to kse structures.
This escaped because DEVICE_POLLING is disabled in LINT being
not compatible with SMP. In fact, it is only a runtime problem,
so if we could recognize that we are building a LINT kernel
we could as well disable the check for SMP being defined.

Reported-by: Joe Clarke
2002-02-15 02:50:07 +00:00
Luigi Rizzo
daccb6386b MFS: synchronize the code with the version in -stable, specifically:
+ SYSCTL_ULONG -> SYSCTL_UINT
 + some procedure renaming and variable rearrangement
 + fix the 'interface going deaf' problem same as in -stable.
2002-02-11 23:56:18 +00:00
Julian Elischer
2c1007663f In a threaded world, differnt priorirites become properties of
different entities.  Make it so.

Reviewed by:	jhb@freebsd.org (john baldwin)
2002-02-11 20:37:54 +00:00
Luigi Rizzo
d105c784d5 Complete the device polling support by adding a thread in charge
of polling interfaces at the lowest possible priority
(this might result in softnetisr being scheduled, but there is
no risk of livelock because they have a higher priority than
this thread).
2001-12-19 00:53:24 +00:00
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