operations before returning. Point the bus at a dummy cam_sim
structure so that any CCBs will complete immediately with a
CAM_DEV_NOT_THERE status, and ensure that any xpt_schedule() calls
on the bus's devices will immediately call the peripheral's
periph_start() routine. Also repeat the async messages because
devices that were part of the way through being probed may appear
after the original AC_LOST_DEVICE was sent, and would otherwise
never go away.
These changes make it possible to deregister a bus and free the SIM
at most stages during bus probing without the usual crashes in
camisr(). In particular, plugging in a umass device and then
unplugging it as soon as the first probe messages appeared would
almost always result in a crash. Now the device just goes away with
a few CAM errors and all references to the CAM bus, target and
device are dropped correctly.
- Only update the rx ring consumer pointer after running through the rx loop,
not with each iteration through the loop.
- If possible, use a fast interupt handler instead of an ithread handler. Use
the interrupt handler to check and squelch the interrupt, then schedule a
taskqueue to do the actual work. This has three benefits:
- Eliminates the 'interrupt aliasing' problem found in many chipsets by
allowing the driver to mask the interrupt in the NIC instead of the
OS masking the interrupt in the APIC.
- Allows the driver to control the amount of work done in the interrupt
handler. This results in what I call 'adaptive polling', where you get
the latency benefits of a quick response to interrupts with the
interrupt mitigation and work partitioning of polling. Polling is still
an option in the driver, but I consider it orthogonal to this work.
- Don't hold the driver lock in the RX handler. The handler and all data
associated is effectively serialized already. This eliminates the cost of
dropping and reaquiring the lock for every receieved packet. The result
is much lower contention for the driver lock, resulting in lower CPU usage
and lower latency for interactive workloads.
The amount of work done in the taskqueue is controlled by the sysctl
dev.em.N.rx_processing_limit
and tunable
hw.em.rx_process_limit
Setting these to -1 effectively removes the limit.
The fast interrupt and taskqueue can be disabled by defining NO_EM_FASTINTR.
This work has been shown to increase fast-forwarding from ~570 kpps to
~750 kpps (note that the same NIC hardware seems unable to transmit more than
800 kpps, so this increase appears to be limited almost solely by the
hardware). Gains have been shown in other workloads, ranging from better
performance to elimination of over-saturation livelocks.
Thanks to Andre Opperman for his time and resources from his network
performance project in performing much of the testing. Thanks to Gleb
Smirnoff and Danny Braniss for their help in testing also.
probe
Before:
5 *
freebsd (195.250.137.134) 19.086 ms 24.694 ms
After:
5 * freebsd (195.250.137.134) 19.086 ms 24.694 ms
Fixes: bin/90098
Reported by: Jeremy Chadwick <freebsd@jdc.parodius.com>
Approved by: andre
MFC after: 1 day
generates a patchset along with a commit message and a commit script if the user has
commit rights.
- Add a README file to give a quick description of each script's purpose.
Approved by: netchild
basically disables any access unless other strings are set in the config
file. Note, that there is no way to set the communities back to NULL once
they're set to something not NULL.
to COMPAT_43TTY.
Add COMPAT_43TTY to NOTES and */conf/GENERIC
Compile tty_compat.c only under the new option.
Spit out
#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.
Instead of dragging the entire ICH4/82801DB into this mess, select
only few boards based on pci subdevice / subvendor.
Tested by: Daisuke Orikasa <luxury-acura-3.5rl at nifty.com>
MFC after: 3 days
fast taskqueues. The following have been added:
TASKQUEUE_FAST_DEFINE() - create a global task queue.
an arbitrary execution context.
TASKQUEUE_FAST_DEFINE_THREAD() - create a global taskqueue that uses a
dedicated kthread.
taskqueue_create_fast() - create a local/private taskqueue.
These are all complimentary of the standard taskqueue functions. They are
primarily useful for fast interrupt handlers that can only use spinlock for
synchronization.
I personally think that the taskqueue API is starting to get too narrow and
hairy, but fixing it will require a major redesign on the API. Such a
redesign would be good but would break compatibility with FreeBSD 6.x, so
it really isn't desirable at this time.
Submitted by: sam
"crontab /etc/crontab", but not the same format due to the who field.
Add some limited anti-foot-shooting support and refuse to load
/etc/crontab as someone's crontab. Users wishing shoot their foot in
this manner may copy /etc/crontab elsewhere. :)
MFC After: 1 week
entries from the interface rather than using ifconfig's delete command.
This preserves non-dhclient configured addresses (though they are wiped
out when dhclient is restarted).
MFC after: 1 week
This option saves packages to PKGDIR (if defined or current directory by default)
as they are downloaded.
Silent a warning when -n is used and package has a +DISPLAY file.
Approved by: krion
MFC after: 1 week
This is based on MCPC USB mobile phone guide line (MCPC-GL005)
Some other 3G system or so will work with this driver.
Kyocera PHS terminal (a.k.a. Kyopon) is known to work, which
is now supported by umodem(4) driver.
o record tsf in tx+rx frames
o switch from raw rssi to dbm for signal data and record both
signal and noise floor data (hacked for now to assume a fixed
noise floor; is correct with new hal)
o add monpass sysctl to control which rx'd frames are passed
up with errors; especially useful to see frames with CRC errors
o mark 'd packets w/ a CRC error with radiotap's BADFCS flag
Also add placeholder code for calibrating the noise floor when
using newer hals.
Reviewed by: avatar
MFC after: 1 week
This is the implementation of the HOSTRES MIB that was developed by
Victor during SoC 2005 with some stylification by philip@ and harti@.
Submitted by: Victor Cruceru <soc-victor@freebsd.org>
Reviewed by: philip, harti
