format specific.
Struct emul has a e_setregs hook back, which points to emulation-specific
setregs function. es_setregs of struct execsw now only points to
optional executable-specific setup function (this is only used for
ECOFF).
- remove special treatment of pager_map mappings in pmaps. this is
required now, since I've removed the globals that expose the address range.
pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
no longer any need to special-case it.
- eliminate struct uvm_vnode by moving its fields into struct vnode.
- rewrite the pageout path. the pager is now responsible for handling the
high-level requests instead of only getting control after a bunch of work
has already been done on its behalf. this will allow us to UBCify LFS,
which needs tighter control over its pages than other filesystems do.
writing a page to disk no longer requires making it read-only, which
allows us to write wired pages without causing all kinds of havoc.
- use a new PG_PAGEOUT flag to indicate that a page should be freed
on behalf of the pagedaemon when it's unlocked. this flag is very similar
to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
pageout fails due to eg. an indirect-block buffer being locked.
this allows us to remove the "version" field from struct vm_page,
and together with shrinking "loan_count" from 32 bits to 16,
struct vm_page is now 4 bytes smaller.
- no longer use PG_RELEASED for swap-backed pages. if the page is busy
because it's being paged out, we can't release the swap slot to be
reallocated until that write is complete, but unlike with vnodes we
don't keep a count of in-progress writes so there's no good way to
know when the write is done. instead, when we need to free a busy
swap-backed page, just sleep until we can get it busy ourselves.
- implement a fast-path for extending writes which allows us to avoid
zeroing new pages. this substantially reduces cpu usage.
- encapsulate the data used by the genfs code in a struct genfs_node,
which must be the first element of the filesystem-specific vnode data
for filesystems which use genfs_{get,put}pages().
- eliminate many of the UVM pagerops, since they aren't needed anymore
now that the pager "put" operation is a higher-level operation.
- enhance the genfs code to allow NFS to use the genfs_{get,put}pages
instead of a modified copy.
- clean up struct vnode by removing all the fields that used to be used by
the vfs_cluster.c code (which we don't use anymore with UBC).
- remove kmem_object and mb_object since they were useless.
instead of allocating pages to these objects, we now just allocate
pages with no object. such pages are mapped in the kernel until they
are freed, so we can use the mapping to find the page to free it.
this allows us to remove splvm() protection in several places.
The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.
This will allow improvements to the pmaps so that they can more easily defer expensive operations, eg tlb/cache flush, til the last possible moment.
Currently this is a no-op on most platforms, so they should see no difference.
Reviewed by Jason.
diagnostic. It's not indicative of an error condition.
The code sequence in question calls fpusave_proc(), which ultimately
calls alpha_pal_wrfen(0), which clears the FEN bit in the current
PCB. However, the diagnostic message is based on reading that bit from
the PCB representation in memory, which is not guaranteed to be kept
up-to-date with respect to the real PCB contents. According to the
AARM, third edition, II-B 4.2:
"If the PCB is read while ownership resides with the processor, it is
UNPREDICTABLE whether the original or an updated value of a field is
read."
The Alpha architecture does not provide a way to read the true value
of the FEN bit of the current PCB, so the test is simply removed.
compiles! Remove all pmax include files, copying 'struct pdma'
from <pmax/dev/pdma.h> into sccvar.h.
XXX: diffs between current pmax and alpha scc.c are almost as large
as the files themselves. Should clean this up...
(SCB_VECTOIDX(vec) - SCB_IOVECBASE] -> SCB_VECTOIDX(vec - SCB_IOVECBASE))
Sigh. This is all very good work- this new interrupt stuff. Yet like the
last time my good friend Jason 'simplified' things, we lost information.
It used to be you could tell which specific slot an interrupt was frame
based upon the vector. Now you can't because they're allocated dynamically.
Oh well- it's not all that important.
Rather than an "iointr" routine that decomposes a vector into an
IRQ, we maintain a vector table directly, hooking up each "iointr"
routine at the correct vector. This also allows us to hook device
interrupts up to specific vectors (c.f. Jensen).
We can shave even more cycles off, here, and I will, but it requires
some changes to the alpha_shared_intr stuff.
simonb