biosextmem > 65536, but biosextmem is a 16-bit quantity so it is
guaranteed to be < 65536. Related cruft for biosbasemem was
mostly cleaned up in rev.1.26.
The default level works with minimal overhead, but one can also enable
full, efficient use of a 512K cache. (Parameters can be generated
to support arbitrary cache sizes also.)
returned by the RTC, use the bootblock supplied value. Also, map the
'stolen by BIOS' memory in the same manner as the ISA-hole memory, since
it is really an extenstion of the BIOS. This is necessary for 32-bit
BIOS functions such as APM support on laptops, and the loss of memory
for non-necessary functions seems to be at most 4k.
Reviewed by: phk
Obtained from: email conversation with jtk@atria.com
nearest .01 Mhz rather than simply truncating it downwards.
This hack makes this 89.999928 Mhz clock correctly round to the closer
90.00-MHz rather than 89.99-MHz:
> i586 clock: 89999928 Hz, i8254 clock: 1193152 Hz
> CPU: Pentium (90.00-MHz 586-class CPU)
Changed i586_ctr_bias from long long to u_int. Only the low 32 bits
are used now that microtime uses a multiplication to do the scaling.
Previously the high 32 bits had to match those of rdtsc() to prevent
overflow traps and invalid timeval adjustments.
early enough when the dump device is specified in the config file.
Removed stale comment about configuration root and swap devices.
Don't bother clearing dumplo when dumpdev is set to NODEV. Everything
is controlled by dumpdev.
Fixed the kern.dumpdev sysctl. Writes were handle bogusly.
problem with the 'shell scripts' was found, but there was a 'strange'
problem found with a 486 laptop that we could not find. This commit
backs the code back to 25-jul, and will be re-entered after the snapshot
in smaller (more easily tested) chunks.
performance issues.
1) The pmap module has had too many inlines, and so the
object file is simply bigger than it needs to be.
Some common code is also merged into subroutines.
2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls.
Unfortunately, a few have needed to be added also.
The removal caused the need for more vm_page_lookups.
I added lookup hints to minimize the need for the
page table lookup operations.
3) Removal of some bogus performance improvements, that
mostly made the code more complex (tracking individual
page table page updates unnecessarily). Those improvements
actually hurt 386 processors perf (not that people who
worry about perf use 386 processors anymore :-)).
4) Changed pv queue manipulations/structures to be TAILQ's.
5) The pv queue code has had some performance problems since
day one. Some significant scalability issues are resolved
by threading the pv entries from the pmap AND the physical
address instead of just the physical address. This makes
certain pmap operations run much faster. This does
not affect most micro-benchmarks, but should help loaded system
performance *significantly*. DG helped and came up with most
of the solution for this one.
6) Most if not all pmap bit operations follow the pattern:
pmap_test_bit();
pmap_clear_bit();
That made for twice the necessary pv list traversal. The
pmap interface now supports only pmap_tc_bit type operations:
pmap_[test/clear]_modified, pmap_[test/clear]_referenced.
Additionally, the modified routine now takes a vm_page_t arg
instead of a phys address. This eliminates a PHYS_TO_VM_PAGE
operation.
7) Several rewrites of routines that contain redundant code to
use common routines, so that there is a greater likelihood of
keeping the cache footprint smaller.
make it more intelligible, improve the partially bogus locking, and
allow for a ``quick re-acquiration'' from a pending release of timer 0
that happened ``recently'', so it was not processed yet by clkintr().
This latter modification now finally allows to play XBoing over
pcaudio without losing sounds or getting complaints. ;-) (XBoing
opens/writes/closes the sound device all over the day.)
Correct locking for sysbeep().
Extensively (:-) reviewed by: bde
Finished the constant poisoning that was begun in rev.1.14. Consts
aren't very poisonous (or useful) unless -Wcast-qual is in CFLAGS,
and it isn't in the default CFLAGS.
