virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.
This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes). It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms. Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.
On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.
which is automatically included during kernel config, and add comments
to individual machine-dependant majors.* files to assign new MI majors
in MI file.
Range 0-191 is reserved for machine-specific assignments, range
192+ are MI assignments.
Follows recent discussion on tech-kern@
- Clean up the way cpu-specific tlb/cache functions are configured
and used.
- Add a workaround for a problem whereby cpu* at superhyway? fails
to probe.
- Print more info about the cpu/cache.
- Move the RESVEC handlers back into generic sh5 code and ditch
the panic stack hack.
- Make the on-chip SCIF device the default console on Cayman.
- Add experimental support for booting via a standalone bootstrap
program (not yet committed) and using the boot parameters passed
in by it.
- Add a few more SH elf constants.
- Tick a couple of items off the TODO list.
cd ${KERNSRCDIR}/${KERNARCHDIR}/compile && ${PRINTOBJDIR}
This is far simpler than the previous system, and more robust with
objdirs built via BSDOBJDIR.
The previous method of finding KERNOBJDIR when using BSDOBJDIR by
referencing _SRC_TOP_OBJ_ from another directory was extremely
fragile due to the depth first tree walk by <bsd.subdir.mk>, and
the caching of _SRC_TOP_OBJ_ (with MAKEOVERRIDES) which would be
empty on the *first* pass to create fresh objdirs.
This change requires adding sys/arch/*/compile/Makefile to create
the objdir in that directory, and descending into arch/*/compile
from arch/*/Makefile. Remove the now-unnecessary .keep_me files
whilst here.
Per lengthy discussion with Andrew Brown.
- Overhaul the TLB management code such that we now keep track of
the exact TLB slot at which a mapping was inserted, both for user-
space and kernel mappings. This addresses #2 on the TODO list.
- Allocate interrupt handles dynamically from a pool(9) to reduce the
number of TLB misses during interrupt dispatch.
- Fully support evcnt(9) in all interrupt dispatchers.
kleink