Currently statclock runs at 64hz, maybe it should be faster or slower, I did
try it being the same as hz, but that just made it look like we spent 10% of
time handling interrupts, rather than the 3% that this gives.
Also fix the IPL_LEVELS for netwinder.
This merge changes the device switch tables from static array to
dynamically generated by config(8).
- All device switches is defined as a constant structure in device drivers.
- The new grammer ``device-major'' is introduced to ``files''.
device-major <prefix> char <num> [block <num>] [<rules>]
- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.
- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.
- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.
- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.
- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.
/dev/ttyS0 crashed the kernel. This is because sacom_filltx uses some
uninitialized static variables. Pulling the salues from softc instead
fixes the problem (this is what was done before the drver was moved
from /sys/arch/hpcarm to /sys/arch/arm, anyway).
the 4M super-section that the PTP will map, not some random 1M
chunk of it. This gives the PTP hint code a much better chance
to working properly, and allows us to tidy up the code that
flushes a PTP from the cache in pmap_destroy().
to do uncached memory access during VM operations (which can be
quite expensive on some CPUs).
We currently write-back PTEs as soon as they're modified; there is
some room for optimization (to write them back in larger chunks).
For PTEs in the APTE space (i.e. PTEs for pmaps that describe another
process's address space), PTEs must also be evicted from the cache
complete (PTEs in PTE space will be evicted durint a context switch).
Change the bus_dmamap_sync() macro to test the ops argument against pre-
and post- constants. The compiler will optimize out dead code because
of the constants. Since post- operations are not needed on ARM (except
for ISA bounce buffers), this eliminate a large number of function calls
which are noops, each of which cost at least 6 cycles just in the call
and return overhead (not to mention whatever other useless work the
compiler decides to do in the callee).
* Save an instruction in the transition from idle to have-process-to-
switch-to, and eliminate two instructions that cause datadep-stalls
on StrongARM And XScale (one in each idle block).
* Rearrange some other instructions to avoid datadep-stalls on StrongARM
and XScale.
* Since cpu_do_powersave == 0 is by far the common case, avoid a
pipeline flush by reordering the two idle blocks.
