Previously whenever PROMISC mode turned on/off link renegotiation
occurs and it could resulted in network unavailability for serveral
seconds.(Depending on switch STP settings it could last several tens
seconds.)
Reported by: Prokofiev S.P. < proks AT logos DOT uptel DOT net >
Tested by: Prokofiev S.P. < proks AT logos DOT uptel DOT net >
The 6105M and 6102 does not have the DWORD alignment problem, so
don't m_defrag() every packet in the transmit path for those.
More stringent usage of tx-descriptor ring and its flags.
Tested on 6102 and 6105M, other chips may also be able to run
without the m_defrag() but I have neither hardware nor docs to
find out.
Sponsored by: Soekris Engineering
use to synchornize and protect all data objects that are used for that
SIM. Drivers that are not yet MPSAFE register Giant and operate as
usual. RIght now, no drivers are MPSAFE, though a few will be changed
in the coming week as this work settles down.
The driver API has changed, so all CAM drivers will need to be recompiled.
The userland API has not changed, so tools like camcontrol do not need to
be recompiled.
implement robust version of m_collapse
add support for sf_buf
add fix for m_iovappend
add calls to m_sanity under INVARIANTS
fix m_freem_vec to correctly travese the mbuf iovec chain
Yukon II generated corrupted TCP checksum for short TCP packets
that's less than 60 bytes in size(e.g. window probe packet, pure ACK
packet etc). Padding the frame with zeros to make the frame minimum
ethernet frame size didn't work at all. Instead of dropping Tx
checksum offload support we calculate TCP checksum with S/W method
when we encounter short TCP frames.
Fortunately it seems that short UDP datagrams appear to be handled
correctly by Yukon II.
While I'm here simplify ethernet/VLAN header size calculation logic.
PR: 111384
anymore. Previously it tried to access interrupt register to disable
interrupts which could result in hang if the hardware was not
properly initialized by system BIOS/ACPI.
Tested by: Benjamin Hansmann (benjamin.hansmann AT rub dot de)
MFC after: 3 days
and flags with an sxlock. This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention. All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently. Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.
- Generally eliminate the distinction between "fast" and regular
acquisisition of the filedesc lock; the plan is that they will now all
be fast. Change all locking instances to either shared or exclusive
locks.
- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
was called without the mutex held; sx_sleep() is now always called with
the sxlock held exclusively.
- Universally hold the struct file lock over changes to struct file,
rather than the filedesc lock or no lock. Always update the f_ops
field last. A further memory barrier is required here in the future
(discussed with jhb).
- Improve locking and reference management in linux_at(), which fails to
properly acquire vnode references before using vnode pointers. Annotate
improper use of vn_fullpath(), which will be replaced at a future date.
In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).
Tested by: kris
Discussed with: jhb, kris, attilio, jeff
Defer mbuf allocation and initialization until after data has already been
received in a cluster
This reduces cpu utilization somewhat, but it only improves the rx path.
Recent changes to TCP appear to make us rate limited by the TX path.
This is the first step in reducing mbuf management overhead for manipulating
clusters.
MFC after: 3 days
been defragged and had their headers in the same cluster as their
payload would be fed to the NIC in header-sized chunks, and would
likely exceed the number of available transmit descriptors.
- If a TSO frame exceeds the number of available transmit descriptors,
don't leak busdmma resources when freeing it.
Sponsored by: Myricom Inc.
in the putc() method. Likewise, in the getc() method, don't check for
received characters with an interval defined in terms of the baudrate.
In both cases it works equally well to implement a fixed delay. More
importantly, it avoids calculating a delay that's roughly 1/10th the
time it takes to send/receive a character. The calculation is costly
and happens for every character sent or received, affecting low-level
console or debug port performance significantly. Secondly, when the
RCLK is not available or unreliable, the delays could disrupt normal
operation.
The fixed delay is 1/10th the time it takes to send a character at
230400 bps.
it obtained through the uart_class structure. This allows us
to declare the uart_class structure as weak and as such allows
us to reference it even when it's not compiled-in.
It also allows is to get the uart_ops structure by name, which
makes it possible to implement the dt tag handling in uart_getenv().
The side-effect of all this is that we're using the uart_class
structure more consistently which means that we now also have
access to the size of the bus space block needed by the hardware
when we map the bus space, eliminating any hardcoding.
