Put a bandaid to prevent ixgbe(4) from completely locking up the system
under high load. Our platform has a few CPU cores and a single active
ixgbe(4) port with 4 queues. Under high enough traffic load, at about
7.5GBs and 700,000 packets/sec (outbound), the entire system would
deadlock. What we found was that each CPU was in an endless loop on a
different ix taskqueue thread. The OACTIVE flag had gotten set on each
queue, and the ixgbe_handle_queue() function was continuously rescheduling
itself via the taskqueue_enqueue. Since all CPUs were busy with their
taskqueue threads, the ixgbe_local_timer() function couldn't run to clear
the OACTIVE flag.
Submitted by: scottl
MFC after: 1 week
it turns out that it negatively affects performance. I'm stil investigating
exactly why deferring the IO causes such negative TCP performance but
doesn't affect UDP preformance.
Leave the ath_tx_kick() change in there however; it's going to be useful
to have that there for if_transmit() work.
PR: kern/168649
called to "kick" along TX.
For now, schedule a taskqueue call.
Later on I may go back to the direct call of ath_rx_tasklet() - but for
now, this will do.
I've tested UDP and TCP TX. UDP TX still achieves 240MBit, but TCP
TX gets stuck at around 100MBit or so, instead of the 150MBit it should
be at. I'll re-test with no ACPI/power/sleep states enabled at startup
and see what effect it has.
This is in preparation for supporting an if_transmit() path, which will
turn ath_tx_kick() into a NUL operation (as there won't be an ifnet
queue to service.)
Tested:
* AR9280 STA
TODO:
* test on AR5416, AR9160, AR928x STA/AP modes
PR: kern/168649
implementing parallel TX and TX/RX completion can be done without
simply abusing long-held locks.
Right now, multiple concurrent ath_start() entries can result in
frames being dequeued out of order. Well, they're dequeued in order
fine, but if there's any preemption or race between CPUs between:
* removing the frame from the ifnet, and
* calling and runningath_tx_start(), until the frame is placed on a
software or hardware TXQ
Then although dequeueing the frame is in-order, queueing it to the hardware
may be out of order.
This is solved in a lot of other drivers by just holding a TX lock over
a rather long period of time. This lets them continue to direct dispatch
without races between dequeue and hardware queue.
Note to observers: if_transmit() doesn't necessarily solve this.
It removes the ifnet from the main path, but the same issue exists if
there's some intermediary queue (eg a bufring, which as an aside also
may pull in ifnet when you're using ALTQ.)
So, until I can sit down and code up a much better way of doing parallel
TX, I'm going to leave the TX path using a deferred taskqueue task.
What I will likely head towards is doing a direct dispatch to hardware
or software via if_transmit(), but it'll require some driver changes to
allow queues to be made without using the really large ath_buf / ath_desc
entries.
TODO:
* Look at how feasible it'll be to just do direct dispatch to
ath_tx_start() from if_transmit(), avoiding doing _any_ intermediary
serialisation into a global queue. This may break ALTQ for example,
so I have to be delicate.
* It's quite likely that I should break up ath_tx_start() so it
deposits frames onto the software queues first, and then only fill
in the 802.11 fields when it's being queued to the hardware.
That will make the if_transmit() -> software queue path very
quick and lightweight.
* This has some very bad behaviour when using ACPI and Cx states.
I'll do some subsequent analysis using KTR and schedgraph and file
a follow-up PR or two.
PR: kern/168649
EARLY_BUILD macro: the -Qunused-arguments flag isn't passed anymore when
building this particular program. However, with clang 3.1 and -Werror,
such unused argument warnings are flagged as errors, causing buildkernel
to fail at this stage, due to the -nostdinc flag passed during linking.
Since the -nostdinc flag isn't actually needed, just remove it.
X-MFC-With: r236528
- Make the device description match the driver name.
- Identify the chip variant based on the JEDEC and use that information
to use the proper values for page count, offset and size instead of
hardcoding a AT45DB642x with 2^N byte page support disabled.
- Take advantage of bioq_takefirst().
- Given that CONTINUOUS_ARRAY_READ_HF (0x0b) command isn't even mentioned
in Atmel's DataFlash Application Note, as suggested by the previous
comment may not work on all all devices and actually doesn't properly
on at least AT45DB321D (JEDEC 0x1f2701), rewrite at45d_task() to use
CONTINUOUS_ARRAY_READ (0xe8) for reading instead. This rewrite is laid
out in a way allowing to easily add support for BIO_DELETE later on.
- Add support for reads and writes not starting on a page boundary.
- Verify the flash content after writing.
- Let at45d_task() gracefully handle errors on SPI transfers and the
device not becoming ready afterwards again. [1]
- Use DEVMETHOD_END. [1]
- Use NULL instead of 0 for pointers. [1]
Additional testing by: Ian Lepore
Submitted by: Ian Lepore [1]
MFC after: 1 week
Make the default role NONE if target mode is selected. This
allows ctl(8) to switch to/from target mode via knob settings.
If we default to role 'none', this causes a reset of the
24XX f/w which then causes initiators to wake up and notice
when we come online.
Reviewed by: kdm
MFC after: 2 weeks
Sponsored by: Spectralogic
(described in ACPICA source code).
- Move intr_disable() and intr_restore() from acpi_wakeup.c to acpi.c
and call AcpiLeaveSleepStatePrep() in interrupt disabled context.
- Add acpi_wakeup_machdep() to execute wakeup MD procedures and call
it twice in interrupt disabled/enabled context (ia64 version is
just dummy).
- Rename wakeup_cpus variable in acpi_sleep_machdep() to suspcpus in
order to be shared by acpi_sleep_machdep() and acpi_wakeup_machdep().
- Move identity mapping related code to acpi_install_wakeup_handler()
(i386 version) for preparation of x86/acpica/acpi_wakeup.c
(MFC candidate).
Reviewed by: jkim@
MFC after: 2 days
DEVICE_RESUME() should be done before AcpiLeaveSleepState() because
PCI config space evaluation can be occurred during control method
executions.
This should fix one of the hang up problems on resuming.
MFC after: 3 days
since batch_len is unused by Linux driver, it seems that it is sometimes
gets passed wrong. This causes command buffer corruption and GPU hung.
Old GEMified DDX drivers that needs this workaround are not supported.
MFC after: 1 month
- Fix some math errors in mmc_decode_csd_sd().
- Fix incorrect arguments to mmc_send_app_op_cond() in mmc_go_discovery().
- Add reporting of CSD for debug purposes.
- Add detection (and skipping) of password-locked cards.
- Add setting of block length on card if necessary.
Submitted by: Patrick Kelsey
MFC after: 3 days
than required for handling MAXPHYS and report the resulting maximum
I/O size to CAM instead of implicitly limiting it to DFLTPHYS.
- Move the variables of sym_action2() out of nested scope as required
by style(9) and remove extraneous curly braces.
- Replace a magic value for PCIR_COMMAND with the appropriate macro.
- Use DEVMETHOD_END.
- Use NULL instead of 0 for pointers.
Tested with a HBA donated by wilko.
MFC after: 3 days
These aren't strictly needed at the moment as we're not doing APSM
and forcing the NIC in and out of network sleep. But, they don't hurt.
Tested:
* AR9280 (mini-PCIe)
Obtained from: Qualcomm Atheros, Linux ath9k
* Now that ah_configPCIE is called for both power on and suspend/resume,
make sure the right bit(s) are cleared and set when suspending and
resuming. Specifically:
+ force disable/enable the PCIe PHY upon suspend/resume;
+ reprogram the PCIe WAR register when resuming and upon power-on.
* Add a recipe which powers down any PCIe PHY hardware inside the AR5416
(which is the PCI variant) to save on power. I have (currently) no way
to test exactly how much power is saved, if any.
Tested on:
* AR5416 cardbus - although unfortunately pccard/cbb/cardbus currently
detaches the NIC upon suspend, I don't think it's a proper test case.
* AR5418 PCIe attached to expresscard - since we're not doing PCIe APSM,
it's also not likely a full/good test case.
In both instances I went through a handful of suspend/resume cycles and
ensured that the STA vap reassociated correctly.
TODO:
* Setup a laptop to simply sit in a suspend/resume loop, making sure that
the NIC always correctly comes back;
* Start doing suspend/resume tests with actual traffic going on in the
background, as I bet this process is all quite racy at the present;
* Test adhoc/hostap mode, just to be completely sure it's working correctly;
* See if I can jury rig an external power source to an AR5416 to test out
whether ah_disablePCIE() works.
Obtained from: Qualcomm Atheros
* Add some other WAR bits (very usefully described too) in preparation for
porting over some suspend/resume fixes from ath9k/Atheros.
Obtained from: Qualcomm Atheros
