length packets, which was actually harmless.
Note that peers with different version of head/ may grow this
counter, but it is harmless - all pfsync data is processed.
Reported & tested by: Anton Yuzhaninov <citrin citrin.ru>
Sponsored by: Nginx, Inc
* The following bit flags where incroccetly defined:
o Mesh Control Present
o Mesh Power Save Level
o RSPI
This is now corrected according to Table 8.4 as per IEEE 802.11 2012;
Approved by: adrian (mentor)
to meaningful value:
- When nfsdcnt is set, it dictates all values;
- Otherwise, nfsdargs.minthreads is set to user specified value, or the
automatically detected value if there is no one specified;
nfsdargs.maxthreads is set to the user specified value, or the value
of nfsdargs.minthreads if there is no one specified; when it is smaller
than nfsdargs.minthreads, the latter's value is always used.
MFC after: 2 weeks
now disables read-ahead. It used to effectively restore the system default
readahead hueristic if it had been changed; a negative value now restores
the default.
Reviewed by: kib
enumeration lock. Make sure all callers of usbd_enum_lock() check the return
value. Remove the control transfer specific lock. Bump the FreeBSD version
number, hence external USB modules may need to be recompiled due to a USB
device structure change.
MFC after: 1 week
My changed had some rather significant behavioural changes to throughput.
The two issues I noticed:
* With if_start and the ifnet mbuf queue, any temporary latency
would get eaten up by some mbufs being queued. With ath_transmit()
queuing things to ath_buf's, I'd only get 512 TX buffers before I
couldn't queue any further frames.
* There's also some non-zero latency involved with TX being pushed
into a taskqueue via direct dispatch. Any time the scheduler didn't
immediately schedule the ath TX task would cause extra latency.
Various 1ge/10ge drivers implement both direct dispatch (if the TX
lock can be acquired) and deferred task transmission (if the TX lock
can't be acquired), with frames being pushed into a drbd queue.
I'll have to do this at some point, but until I figure out how to
deal with 802.11 fragments, I'll have to wait a while longer.
So what I saw:
* lots of extra latency, specially under load - if the taskqueue
wasn't immediately scheduled, things went pear shaped;
* any extra latency would result in TX ath_buf's taking their sweet time
being replenished, so any further calls to ath_transmit() would drop
mbufs.
* .. yes, there's no explicit backpressure here - things are just dropped.
Eek.
With this, the general performance has gone up, but those subtle if_start()
related race conditions are back. For some reason, this is doubly-obvious
with the AR5416 NIC and I don't quite understand why yet.
There's an unrelated issue with AR5416 performance in STA mode (it's
fine in AP mode when bridging frames, weirdly..) that requires a little
further investigation. Specifically - it works fine on a Lenovo T40
(single core CPU) running a March 2012 9-STABLE kernel, but a Lenovo T60
(dual core) running an early November 2012 kernel behaves very poorly.
The same hardware with an AR9160 or AR9280 behaves perfectly.
