Historical behavior of letting other CPUs merily go on is a default for
time being. The new behavior can be switched on via
kern.stop_scheduler_on_panic tunable and sysctl.
Stopping of the CPUs has (at least) the following benefits:
- more of the system state at panic time is preserved intact
- threads and interrupts do not interfere with dumping of the system
state
Only one thread runs uninterrupted after panic if stop_scheduler_on_panic
is set. That thread might call code that is also used in normal context
and that code might use locks to prevent concurrent execution of certain
parts. Those locks might be held by the stopped threads and would never
be released. To work around this issue, it was decided that instead of
explicit checks for panic context, we would rather put those checks
inside the locking primitives.
This change has substantial portions written and re-written by attilio
and kib at various times. Other changes are heavily based on the ideas
and patches submitted by jhb and mdf. bde has provided many insights
into the details and history of the current code.
The new behavior may cause problems for systems that use a USB keyboard
for interfacing with system console. This is because of some unusual
locking patterns in the ukbd code which have to be used because on one
hand ukbd is below syscons, but on the other hand it has to interface
with other usb code that uses regular mutexes/Giant for its concurrency
protection. Dumping to USB-connected disks may also be affected.
PR: amd64/139614 (at least)
In cooperation with: attilio, jhb, kib, mdf
Discussed with: arch@, bde
Tested by: Eugene Grosbein <eugen@grosbein.net>,
gnn,
Steven Hartland <killing@multiplay.co.uk>,
glebius,
Andrew Boyer <aboyer@averesystems.com>
(various versions of the patch)
MFC after: 3 months (or never)
The global variables and functions provided by rcorder.c are not used in
the other C files, as the other C files only provide memory allocation
and hash functions. This reduces the binary size by 10%.
AIM systems to 4 GB on 32-bit systems and 2^64 bytes on 64-bit systems.
VM_MAXUSER_ADDRESS remains at 2 GB on pending Book-E, pending review of
an increase to 3 GB by those more familiar with Book-E.
pmap_remove() for large sparse requests. This can prevent pmap_remove()
operations on 64-bit process destruction or swapout that would take
several hundred times the lifetime of the universe to complete. This
behavior is largely indistinguishable from a hang.
VM_KMEM_SIZE_MAX. Specifically, if the user/kernel address space split
was changed such that the kernel address space was greater than or equal
to 2 GB, then overflow would occur.
PR: 161721
MFC after: 3 weeks
There have still been intermittent problems with apparent TX
hangs for some customers. These have been problematic to reproduce
but I believe these changes will address them. Testing on a number
of fronts have been positive.
EM: there is an important 'chicken bit' fix for 82574 in the shared
code this is supported in the core here.
- The TX path has been tightened up to improve performance. In
particular UDP with jumbo frames was having problems, and the
changes here have improved that.
- OACTIVE has been used more carefully on the theory that some
hangs may be due to a problem in this interaction
- Problems with the RX init code, the "lazy" allocation and
ring initialization has been found to cause problems in some
newer client systems, and as it really is not that big a win
(its not in a hot path) it seems best to remove it.
- HWTSO was broken when VLAN HWTAGGING or HWFILTER is used, I
found this was due to an error in setting up the descriptors
in em_xmit.
IGB:
- TX is also improved here. With multiqueue I realized its very
important to handle OACTIVE only under the CORE lock so there
are no races between the queues.
- Flow Control handling was broken in a couple ways, I have changed
and I hope improved that in this delta.
- UDP also had a problem in the TX path here, it was change to
improve that.
- On some hardware, with the driver static, a weird stray interrupt
seems to sometimes fire and cause a panic in the RX mbuf refresh
code. This is addressed by setting interrupts late in the init
path, and also to set all interrupts bits off at the start of that.
support of new deltas for both em and igb drivers.
Note that I am not able to track all the bugs fixed in
this code, I am a consumer of it as a component of my
core drivers. It is important to keep the FreeBSD drivers
up to date with it however.
One important note is there is a key fix for 82574 in this
update. Also, there are lots of white space changes, I am
not happy about them but have no control over it :)
attack vector against applications that allow the applicant to specify
which policy to apply.
Submitted by: Matthias Drochner <drochner@netbsd.org>
MFC after: 1 week
- While here, make this compile and work on non-i386:
- Use CMSG_SPACE(), CMSG_LEN(), and CMSG_FIRSTHDR() instead of ignoring
padding between 'struct cmsghdr' and control message payloads.
- Don't initialize the control message before calling recvmsg().
Instead, check that we get a valid control message on return from
recvmsg().
- Use errx() instead of err() for some errors that don't report failures
that set errno.
Requested by: kib (1)
control. Controller does not automatically generate pause frames
based on number of available RX buffers so it's very hard to
know when driver should generate XON frame in time. The only
mechanism driver can detect low number of RX buffer condition is
ET_INTR_RXRING0_LOW or ET_INTR_RXRING1_LOW interrupt. This
interrupt is generated whenever controller notices the number of
available RX buffers are lower than pre-programmed value(
ET_RX_RING0_MINCNT and ET_RX_RING1_MINCNT register). This scheme
does not provide a way to detect when controller sees enough number
of RX buffers again such that efficient generation of XON/XOFF
frame is not easy.
While here, add more flow control related register definition.
interrupt is ours. Note, interrupts are automatically ACKed when
the status register is read.
Add RX/TX DMA error to interrupt handler and do full controller
reset if driver happen to encounter these errors. There is no way
to recover from these DMA errors without controller reset.
Rename local variable name intrs with status to enhance
readability.
While I'm here, rename ET_INTR_TXEOF and ET_INTR_RXEOF to
ET_INTR_TXDMA and ET_INTR_RXDMA respectively. These interrupts
indicate that a frame is successfully DMAed to controller's
internal FIFO and they have nothing to do with EOF(end of frame).
Driver does not need to wait actual end of TX/RX of a frame(e.g.
no need to wait the end signal of TX which is generated when a
frame in TX FIFO is emptied by MAC). Previous names were somewhat
confusing.
of a devfs file descriptor in devfs_close_f(). The passed in td argument
may be NULL if the close was invoked by garbage collection of open
file descriptors in pending control messages in the socket buffer of a
UNIX domain socket after it was closed.
PR: kern/151758
Submitted by: Andrey Shidakov andrey shidakov ru
Submitted by: Ruben van Staveren ruben verweg com
Reviewed by: kib
MFC after: 2 weeks
thread_free(newtd). This to avoid a possible page fault in
cpu_thread_clean() as seen on amd64 with syscall fuzzing.
Reviewed by: kib
MFC after: 1 week
