vfs_mount_alloc/vfs_mount_destroy functions and take care to completely
destroy the mount point along with its locks. Mount struct has grown in
coplexity recently and depending on each failure path to destroy it
completely isn't working anymore.
2. Eliminate largely identical vfs_mount and vfs_unmount question by
moving the code to handle both cases into a newly introduced vfs_domount
function.
3. Simplify nfs_mount_diskless to always expect an allocated mount
struct and never attempt an allocation/destruction itself. The
vfs_allocroot allocation was there to support 'magic' swap space
configuration for diskless clients that was already removed by PHK some
time ago.
4. Include a vfs_buildopts cleanups by Peter Edwards to validate the
sanity of nmount parameters passed from userland.
Submitted by: (4) Peter Edwards <peter.edwards@openet-telecom.com>
Reviewed by: rwatson
* Add missing `utility' word to sentence describing
ips(4) card configuration.
* Remove extraneous use of .Pp, and describe the tunable
hw.ips.0.disable in a better way.
* Replace wrongly used .Op mdoc macros with the .Bq macro.
The .Op macro should only be used when describing a
``usage'' line of a utility/command.
* Add .Er, for marking errno defines (ENOMEM etc etc)
important change is in cpu_switch() where we disable the high FP
registers for the thread that we switch-out if the CPU currently
has its high FP registers. This avoids that the high FP registers
remain enabled for the thread even when the CPU has unloaded them
or the thread migrated to another processor.
Likewise, when we switch-in a thread of that has its high FP
registers on the CPU, we enable them. This avoids an otherwise
harmless, but unnecessary trap to have them enabled.
The code that handles the disabled high FP trap (in trap()) has
been turned into a critical section for the most part to avoid
being preempted. If there's a race, we bail out and have the
processor trap again if necessary.
Avoid using the generic ia64_highfp_save() function when the
context is predictable. The function adds unnecessary overhead.
Don't use ia64_highfp_load() for the same reason. The function
is now unused and can be removed.
These changes make the lazy context switching of the high FP
registers in an UP kernel functional.
turnstiles to implement blocking isntead of implementing a thread queue
directly. These turnstiles are somewhat similar to those used in Solaris 7
as described in Solaris Internals but are also different.
Turnstiles do not come out of a fixed-sized pool. Rather, each thread is
assigned a turnstile when it is created that it frees when it is destroyed.
When a thread blocks on a lock, it donates its turnstile to that lock to
serve as queue of blocked threads. The queue associated with a given lock
is found by a lookup in a simple hash table. The turnstile itself is
protected by a lock associated with its entry in the hash table. This
means that sched_lock is no longer needed to contest on a mutex. Instead,
sched_lock is only used when manipulating run queues or thread priorities.
Turnstiles also implement priority propagation inherently.
Currently turnstiles only support mutexes. Eventually, however, turnstiles
may grow two queue's to support a non-sleepable reader/writer lock
implementation. For more details, see the comments in sys/turnstile.h and
kern/subr_turnstile.c.
The two primary advantages from the turnstile code include: 1) the size
of struct mutex shrinks by four pointers as it no longer stores the
thread queue linkages directly, and 2) less contention on sched_lock in
SMP systems including the ability for multiple CPUs to contend on different
locks simultaneously (not that this last detail is necessarily that much of
a big win). Note that 1) means that this commit is a kernel ABI breaker,
so don't mix old modules with a new kernel and vice versa.
Tested on: i386 SMP, sparc64 SMP, alpha SMP
- Fail in agp_alloc_gatt if the aperture size is 0 instead of panicing in
contigmalloc.
Reported by: Bjoern Fischer <bfischer@Techfak.Uni-Bielefeld.DE>
Reviewed by: jhb
MFC after: 1 week
interrupt such as IRQ 22 or 19. However, the ACPI BIOS still routes
interrupts from some PCI devices to the same intpin calling the pin
IRQ 22. Thus, ACPI expects to address a single interrupt source via two
different names. To work around this, if the SCI is remapped to a non-ISA
interrupt (i.e., greater than 15), then we use
acpi_OverrideInterruptLevel() function to tell ACPI to use IRQ 22 or 19
rather than IRQ 9 for the SCI.
Previously we would change IRQ 22 or 19's name to IRQ 9 when we encountered
such an Interrupt Source Override entry in the MADT which routed the SCI
properly but left PCI devices mapped to IRQ 22 or 19 w/o a routable
interrupt.
Tested by: sos
This ensures that uart gets a higher console priority than syscons when
a serial console is being used. Testing against the "console" environment
variable doesn't make sense since we only have one loader console driver.
should now only have HTT CPUs if they have explicitly asked for them
either by enabling HyperThreading in the BIOS or by using the
MPTABLE_FORCE_HTT kernel option.
should only be used if they are enabled in the BIOS. Now that we support
enumerating CPUs using the ACPI MADT, any HTT machine using ACPI should
respect the BIOS setting. For HTT machines with ACPI disabled in the
kernel, the MPTABLE_FORCE_HTT kernel option can be used to try to probe HTT
CPUs like have done in the past for the MP Table case. This option should
only be enabled if HTT is enabled in the BIOS.
that we currently do not keep track of whether the thread has
actually used the high FP registers before. If not, we should
not save them in the context which automaticly means that we
also would not restore them from the context. For now, do it
unconditionally so that we can reach functional completeness.
functions switched to using {g|s}et_mcontext(). The problem is that
sigreturn(), being a syscall, can be given an async. context (i.e.
one corresponding to an interrupt or trap). When this happens, we
try to return to user mode via epc_syscall_return with a trapframe
that can only be used to return to user mode via exception_restore.
To fix this, we check the frame's flags immediately prior to
epc_syscall_return and branch to exception_restore for non-syscall
frames. Modify the assertion in set_mcontext() to check that if
there's a mismatch, it's because of sigreturn().
ktr_resize_pool(); this eliminates a potential livelock.
Return ENOSPC only if we encountered an out-of-memory condition when
trying to increase the pool size.
Reviewed by: jhb, bde (style)
