than as one-off hacks in various other parts of the kernel:
- Add a function maybe_preempt() that is called from sched_add() to
determine if a thread about to be added to a run queue should be
preempted to directly. If it is not safe to preempt or if the new
thread does not have a high enough priority, then the function returns
false and sched_add() adds the thread to the run queue. If the thread
should be preempted to but the current thread is in a nested critical
section, then the flag TDF_OWEPREEMPT is set and the thread is added
to the run queue. Otherwise, mi_switch() is called immediately and the
thread is never added to the run queue since it is switch to directly.
When exiting an outermost critical section, if TDF_OWEPREEMPT is set,
then clear it and call mi_switch() to perform the deferred preemption.
- Remove explicit preemption from ithread_schedule() as calling
setrunqueue() now does all the correct work. This also removes the
do_switch argument from ithread_schedule().
- Do not use the manual preemption code in mtx_unlock if the architecture
supports native preemption.
- Don't call mi_switch() in a loop during shutdown to give ithreads a
chance to run if the architecture supports native preemption since
the ithreads will just preempt DELAY().
- Don't call mi_switch() from the page zeroing idle thread for
architectures that support native preemption as it is unnecessary.
- Native preemption is enabled on the same archs that supported ithread
preemption, namely alpha, i386, and amd64.
This change should largely be a NOP for the default case as committed
except that we will do fewer context switches in a few cases and will
avoid the run queues completely when preempting.
Approved by: scottl (with his re@ hat)
to <sys/gmon.h>. Cleaned them up a little by not attempting to ifdef
for incomplete and out of date support for GUPROF in userland, as in
the sparc64 version.
remove the empty line between the fdc and sio devices. The empty
line suggests that the comment applies to fdc only while it applies
to all following devices and options.
Typo spotted by: ru@
gets the relocation base passed in relocbase, we cannot declare a
local variable with the same name. Assume the argument holds the
same value as the local variable did...
elf_reloc() backends for two reasons. First, to support the possibility
of there being two elf linkers in the kernel (eg: amd64), and second, to
pass the relocbase explicitly (for relocating .o format kld files).
the kernel. We can guarantee this by resetting the FP status register.
This masks all FP traps. The reason we did get FP traps was that we
didn't reset the FP status register in all cases.
Make sure to reset the FP status register in syscall(). This is one of
the places where it was forgotten.
While on the subject, reset the FP status register only when we trapped
from user space.
individual asm versions. The global lock is shared between the BIOS and
OS and thus cannot use our mutexes. It is defined in section 5.2.9.1 of
the ACPI specification.
Reviewed by: marcel, bde, jhb
o Fix and improve comments and references,
o Add PFIL_HOOKS, UFS_ACL and UFS_DIRHASH,
o Switch from SCHED_4BSD to SCHED_ULE,
o Remove SCSI_DELAY (there's no SCSI support),
move its declaration to the machine-dependent header file on those
machines that use it. In principle, only i386 should have it.
Alpha and AMD64 should use their direct virtual-to-physical mapping.
- Remove pmap_kenter_temporary() from ia64. It is unused. Approved
by: marcel@
distinguish between debugger inserted breakpoints and fixed
breakpoints. While here, make sure the break instruction never
ends up in the last slot of a bundle by forcing it to be an
M-unit instruction. This makes it easier for use to skip over
it.
level of abstraction for any and all CPU mask and CPU bitmap variables
so that platforms have the ability to break free from the hard limit
of 32 CPUs, simply because we don't have more bits in an u_int. Note
that the type is not supposed to solve massive parallelism, where
the number of CPUs can be larger than the width of the widest integral
type. As such, cpumask_t is not supposed to be a compound type. If
such would be necessary in the future, we can deal with the issues
then and there. For now, it can be assumed that the type is integral
and unsigned.
With this commit, all MD definitions start off as u_int. This allows
us to phase-in cpumask_t at our leasure without breaking anything.
Once cpumask_t is used consistently, platforms can switch to wider
(or smaller) types if such would be beneficial (or not; whatever :-)
Compile-tested on: i386
for uart(4) to figure out which device to use as console. Use this file
to define hw.uart.console instead so that we don't have to put it in
the default loader.conf, which makes it hard to override.
dependent function by the same name and a machine-independent function,
sf_buf_mext(). Aside from the virtue of making more of the code machine-
independent, this change also makes the interface more logical. Before,
sf_buf_free() did more than simply undo an sf_buf_alloc(); it also
unwired and if necessary freed the page. That is now the purpose of
sf_buf_mext(). Thus, sf_buf_alloc() and sf_buf_free() can now be used
as a general-purpose emphemeral map cache.
based on the Madison core and targeting the low end of the spectrum.
Its clock frequency is 1Ghz, whereas Madison starts at 1.3Ghz. Since
the CPUID information is the same for Madison and Deerfield, we use
the clock frequency to identify the processor.
Supposedly the Deerfield only uses 62W, which seems to be less than
modern Xeon processors (about 70W) and about half what a Madison would
need.
