side-effect of purging more than the requested translation. While
this is not a problem in general, it invalidates the assumption made
during constructing the trapframe on entry into the kernel in SMP
configurations. The assumption is that only the first store to the
stack will possibly cause a TLB miss. Since the ptc.g purges the
translation caches of all CPUs in the coherency domain, a ptc.g
executed on one CPU can cause a purge on another CPU that is
currently running the critical code that saves the state to the
trapframe. This can cause an unexpected TLB miss and with interrupt
collection disabled this means an unexpected data nested TLB fault.
A data nested TLB fault will not save any context, nor provide a
way for software to determine what caused the TLB miss nor where
it occured. Careful construction of the kernel entry and exit code
allows us to handle a TLB miss in precisely orchastrated points
and thereby avoiding the need to wire the kernel stack, but the
unexpected TLB miss caused by the ptc.g instructution resulted in
an unrecoverable condition and resulting in machine checks.
The solution to this problem is to synchronize the kernel entry
on all CPUs with the use of the ptc.g instruction on a single CPU
by implementing a bare-bones readers-writer lock that allows N
readers (= N CPUs entering the kernel) and 1 writer (= execution
of the ptc.g instruction on some CPU). This solution wins over
a rendez-vous approach by not interrupting CPUs with an IPI.
This problem has not been observed on the Montecito.
PR: ia64/147772
MFC after: 6 days
a real (inline) function or applying void casting for all its consumers.
In most of places, the "return value" is not checked nor assigned, which
causes too many warnings for some smart compilers, i.e., clang.
Found by: clang
Remove unneeded rxtx handler, make que handler generic.
Do not allocate header mbufs in rx ring if not doing hdr split.
Release the lock in rxeof call to stack.
MFC for 8.1 asap
"arp -an" when using a lot of aliases (on a single interface).
A better fix would include a better interface for if_indextoname than
getting the whole address list from the kernel just to find the one
index->name mapping.
Reported & analyzed by: Nick Rogers
MFC after: 3 days
via %s
Most of the cases looked harmless, but this is done for the sake of
correctness. In one case it even allowed to drop an intermediate buffer.
Found by: clang
MFC after: 2 week
Apparently it's bad when we first have an ANSI prototype in function
declaration, but then use K&R in its defintion.
Complaint from: clang
MFC after: 2 weeks
per-buf flag to catch if a buf is double-counted in the free count.
This code was useful to debug an instance where a local patch at Isilon
was incorrectly managing numfreebufs for a new buf state.
Reviewed by: jeff
Approved by: zml (mentor)
CPU_FOREACH(i) iterates over the CPU IDs of all available CPUs. The
CPU_FIRST() and CPU_NEXT(i) macros can also be used to iterate over
available CPU IDs. CPU_NEXT(i) wraps around to CPU_FIRST() rather than
returning some sort of terminator.
Requested by: rwatson
Reviewed by: attilio
allow pmap_enter() to be performed on an unmanaged page that doesn't have
VPO_BUSY set. Having VPO_BUSY set really only matters for managed pages.
(See, for example, pmap_remove_write().)
shared resources defaults beyond absolute minimums.
The new values are chosen mostly by magic. They are still fairly
small and will need increasing for large installations (especially
SHMMAX). However, they are now enough to e.g. start PostgreSQL
installations with ~~300 users and nearly 512 MB of shared buffers.
Reviewed by: A short discussion on hackers@
- .Nd in section NAME is not optional
- .Ed was missing
- "indent" is not a flag, but a literal argument for -offset
- stop switching font sizes for acronyms
- use .Brq instead of rolling our own
This is harmless with OpenSolaris fex and yacc, but with FreeBSD
causes '\xff' symbol to be physically put into input buffer, causing
subsequent syntax error.
MFC after: 1 week
a) There was a case where a ICMP message could cause
us to return leaving a stuck lock on an stcb.
b) The iterator needed some tweaks to fix its lock
ordering.
c) The ITERATOR_LOCK is no longer needed in the freeing
of a stcb. Now that the timer based one is gone we don't
have a multiple resume situation. Add to that that there
was somewhere a path out of the freeing of an assoc that
did NOT release the iterator_lock.. it was time to clean
this old code up and in the process fix the lock bug.
MFC after: 1 week
in particular, do not handle deferred DMA map load operations at all.
Any error, and especially EINPROGRESS, is treated as a hard error and
typically abort the current operation. The fact that the busdma code
queues the load operation for when resources (i.e. bounce buffers in
this particular case) are available makes this especially problematic.
Bounce buffering, unlike what the PR synopsis would suggest, works
fine.
While on the subject, properly implement swi_vm().
PR: 147502
MFC after: 1 week
Enhance Makefile.inc processing, when asked for, to include the most
specific (MACHINE specific) to least specific (MACHINE_CPUARCH).
Reviewed by: arch@ (mostly silence though)
Introduce MACHINE_CPUARCH. Many different MACHINE_ARCHs will be built
from one MACHINE_CPUARCH. This will allow us to move to a more
standard MACHINE_ARCH for mips and arm which exist in many different
endian variants, and for powerpc where both 32 and 64 bit binaries are
generated from the same sources.
Reviewed by: arch@ (mostly silence though)
802.11 duplicate detection. Upon looking at the standard, we discover
that 802.11-2007 says:
"A receiving QoS STA is also required to keep only the most recent
cache entry per<Address 2, TID, sequence-number> triple, storing only
the most recently received fragment number for that triple. A receiving
STA may omit tuples obtained from broadcast/multicast or ATIM frames
from the cache."
To fix this, we just disable duplicate detection for multicast/broadcast
frames.
Reviewed by: sam
MFC after: 4 weeks
Obtained from: DragonFly
