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.
with the PROM. From Valeriy E. Ushakov. This is a hack, but as long as
we don't have a way to arrange for a proper VA layout on this machines
(i.e. beyound the PROM) it is needed.
to a 2-clause licence (retaining UCB clauses (1) and (2)), per PR
22409 from Joel Baker, approved by Theo de Raadt, and ratified by
myself - the only discrepancy being the handling of the original
clause 3 in src/usr.sbin/yppoll/yppoll.c.
Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.
Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.
All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.
PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.
- factor out disksubr.c between sun3, sparc and sparc64. Keep the sun3
groveling code to find a NetBSD disklabel in the first sector (so that it
can find a label at the old sun3 LABELOFFSET) as a fallback is not
label at LABELOFFSET, or sun label is present.
- Fix the sun3 LABELOFFSET (was 64, but the kernel wrote the NetBSD label at
128)
- Make next68k disksubr.c always write a next-compatible disklabel.
- remove #ifdef __sparc__ hack from disklabel(8), and change it to issue
a DIOCWDINFO after writing the disklabel to the raw partition in the
-r/-I case (so that the kernel can convert the label if needed).
copyin() or copyout().
uvm_useracc() tells us whether the mapping permissions allow access to
the desired part of an address space, and many callers assume that
this is the same as knowing whether an attempt to access that part of
the address space will succeed. however, access to user space can
fail for reasons other than insufficient permission, most notably that
paging in any non-resident data can fail due to i/o errors. most of
the callers of uvm_useracc() make the above incorrect assumption. the
rest are all misguided optimizations, which optimize for the case
where an operation will fail. we'd rather optimize for operations
succeeding, in which case we should just attempt the access and handle
failures due to insufficient permissions the same way we handle i/o
errors. since there appear to be no good uses of uvm_useracc(), we'll
just remove it.
Tested on SS1+ (mainbus), but not tested on sun4/sun4m (obio).
XXX maybe this file should be split into mainbus and obio attachments
XXX and moved into sys/arch/sparc/dev or sys/dev/sun.
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().
Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().
pk