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
a 82557 (e.g.: a newer chip) then:
+ enable MWI, if the PCI configuration indicates the system supports it
+ enable usage of extended TxCB, for better performance
+ enable hardware flow control. FC frames will be passed up to the
host only if promiscuous mode is enabled.
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
an override as a loader settable variable (fxp_iomap). fxp_iomap is
a bitmap of fxp units that should be configured to use PCI I/O space
in stead of PCI Memory space.
Reviewed by: Kees Jan Koster <dutchman@tccn.cs.kun.nl>, dg@freebsd.org
is enabling as all entries are still called with Giant being held.
Maintaining compatability with NetBSD makes what should be very simple
kinda ugly.
Reviewed by: Jason Evans
address size that is different than the standard 6bits. This fixes
support for the Compaq NC3121 card, certain newer Intel Pro/100+
cards, and should also fix integrated NICs on SuperMicro and Compaq
motherboards.
The auto-sizing algorithm was taken from NetBSD (thanks!), which I
think got it from Linux originally.
Thanks also to Andrew Sparrow <spadger@best.com> and Joe Moore
<jomor@ahpcns.com> for supplying me with unworking Compaq and Intel
cards to develop and test the fixes with.
and/or when using the card.
o Convert the driver to using bus_space. This allows alphas with
fxp's to boot, rather than panic'ing because rman_get_virtual()
doesn't really return a virtual address on alphas.
o Fix an alpha unaligned access error caused by some misfeature of
gcc/egcs: if link_addr & rbd_addr in the fxp_rfa struct are 32 bit
quantities, egcs will assume they are naturally aligned. So it will do
a ldl & some shifty/masky to twiddle 16 bit values in fxp_lwcopy().
However, if they are 16-bit aligned, the ldl will actually be done on
a 16-bit aligned value & we will panic with an unaligned access
error... Changing their definition to an array of chars seems to fix
this. I obtained this from NetBSD.
I've tested this on both i386 & alpha.
i386 platform boots, it is no longer ISA-centric, and is fully dynamic.
Most old drivers compile and run without modification via 'compatability
shims' to enable a smoother transition. eisa, isapnp and pccard* are
not yet using the new resource manager. Once fully converted, all drivers
will be loadable, including PCI and ISA.
(Some other changes appear to have snuck in, including a port of Soren's
ATA driver to the Alpha. Soren, back this out if you need to.)
This is a checkpoint of work-in-progress, but is quite functional.
The bulk of the work was done over the last few years by Doug Rabson and
Garrett Wollman.
Approved by: core
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
if it is in 10Mbps mode and gets certain types of garbage prior to
the packet header. The work-around involves reprogramming the
multicast filter if nothing is received in some number of seconds
(currently set at 15). As a side effect, implemented complete support
for multicasting rather than the previous 'receive all multicasts'
hack, since we now have the ability to program the filter table.
Fixed a serious bug which crept in with the timeout() changes;
the cookie was only saved on the first timeout() call in fxp_init()
and wasn't updated in the most common place in fxp_stats_update()
when the timeout was rescheduled. This bug would have resulted in
an eventual panic if fxp_stop() was called (which happens when any
interface flags are changed, for example).
Fixed a bug in Alpha support that would have caused the TxCB
descriptor chain to span a page boundry, causing serious problems
if the pages didn't happen to be contiguous.
Removed some gratuitous bit masking that was left over from an
older implementation.
Fixed a bug where too much was copied from the configuration
template, spilling over into memory that followed it.
Fixed handling of if_timer...it was cleared too early in some cases.
