creation of large page mappings in the pmap, it can provide modest
performance benefits. In particular, for a "buildworld" on a 2x 1GHz
Ultrasparc IIIi it reduced the wall clock time by 2.2% and the system
time by 12.6%.
Tested by: marius@
Add a drain function for struct sysctl_req, and use it for a variety
of handlers, some of which had to do awkward things to get a large
enough SBUF_FIXEDLEN buffer.
Note that some sysctl handlers were explicitly outputting a trailing
NUL byte. This behaviour was preserved, though it should not be
necessary.
Reviewed by: phk (original patch)
unexpected things in copyout(9) and so wiring the user buffer is not
sufficient to perform a copyout(9) while holding a random mutex.
Requested by: nwhitehorn
handlers, some of which had to do awkward things to get a large enough
FIXEDLEN buffer.
Note that some sysctl handlers were explicitly outputting a trailing NUL
byte. This behaviour was preserved, though it should not be necessary.
Reviewed by: phk
a reservation, unless all of the reservation's pages were free, the
reservation was moved to the head of the partially-populated reservations
queue, where it would be the next reservation to be broken in case the
free page queues were emptied. Now, instead, I am moving it to the tail.
Very likely this reservation is in the process of being freed in its
entirety, so placing it at the tail of the queue makes it more likely that
the underlying physical memory will be returned to the free page queues as
one contiguous chunk. If a reservation must be broken, it will, instead,
be the longest unchanged reservation, which is arguably the reservation
that is least likely to ever achieve promotion or be freed in its entirety.
MFC after: 6 weeks
contigmalloc(9) as a last resort to steal pages from an inactive,
partially-used superpage reservation.
Rename vm_reserv_reclaim() to vm_reserv_reclaim_inactive() and
refactor it so that a separate subroutine is responsible for breaking
the selected reservation. This subroutine is also used by
vm_reserv_reclaim_contig().
machine-independent support for superpages. (The earlier part was
the rewrite of the physical memory allocator.) The remainder of the
code required for superpages support is machine-dependent and will
be added to the various pmap implementations at a later date.
Initially, I am only supporting one large page size per architecture.
Moreover, I am only enabling the reservation system on amd64. (In
an emergency, it can be disabled by setting VM_NRESERVLEVELS to 0
in amd64/include/vmparam.h or your kernel configuration file.)
