Eliminate unnecessary, recursive acquisitions and releases of the page
queues lock by free_pv_entry() and pmap_remove_pages().
Reduce the scope of the page queues lock in pmap_remove_pages().
that it just warns the user with a printf when it misaligns a piece
of memory that was requested through a busdma tag.
Some drivers (such as mpt, and probably others) were asking for alignments
that could not be satisfied, but as far as driver operation was concerned,
that did not matter. In the theory that other drivers will fall into
this same category, we agreed that panicing or making the allocation
fail will cause more hardship than is necessary. The printf should
be sufficient motivation to get the driver glitch fixed.
POSIX (susv3) requires this, but it is unclear what should be inherited,
duplicating whole 387 stack for new thread seems to be unnecessary and
dangerous. Revert to previous code, force a new thread to be started with
clean FP state.
the high 16 bits is non-zero, fxrstor instruction will generate GP fault,
resulting kernel crash, this bug can be triggered by setcontext and
ptrace(PT_SETXMMREGS).
other timeouts could not happen while suspending, including timeouts
for things like msleep. This caused the system to hang on suspend
when the cbb was enabled, since its suspend path powered down the
socket which used a timeout to wait for it to be done.
APM now creates a thread when it is enabled, and deletes the thread
when it is disabled. This thread takes the place of the timeout by
doing its polling every ~.9s. When the thread is disabled, it will
wakeup early, otherwise it times out and polls the varius things the
old timeout polled (APM events, suspend delays, etc).
This makes my Sony VAIO 505TS suspend/resume correctly when APM is
enabled (ACPI is black listed on my 505TS).
This will likely fix other problems with the suspend path where
drivers would sleep with msleep and/or do other timeouts. Maybe
there's some special case code that would use DELAY while suspending
and msleep otherwise that can be revisited and removed.
This was also tested by glebius@, who pointed out that in the patch I
sent him, I'd forgotten apm_saver.c
MFC After: 3 weeks
lnc(4) on PC98 and i386. The ISA front-end supports the same non-PNP
network cards as lnc(4) did and additionally a couple of PNP ones.
Like lnc(4), the C-bus front-end of le(4) only supports C-NET(98)S
and is untested due to lack of such hardware, but given that's it's
based on the respective lnc(4) and not too different from the ISA
front-end it should be highly likely to work.
- Remove the descriptions of le(4), which where converted from lnc(4),
from sys/i386/conf/NOTES and sys/pc98/conf/NOTES as there's a common
one in sys/conf/NOTES.
entry to the PCI NICs section so it's in the same spot in all GENERIC
config files.
- Add a note to the description of pcn(4) informing that is has precedence
over le(4).
Remove an unnecessary check of the table's bus clock. CPUs that
support this feature export only the high/low settings via the MSR,
packed into 32 bits.
Hardware from: Centaur Technologies
MFC after: 1 week
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:
struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};
Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.
Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.
This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.
Sponsored by: IronPort Systems
conformance with the mbuf and uio load routines. ENOMEM can only happen
with BUS_DMA_NOWAIT is passed in, thus the deferals are disabled. I don't
like doing this, but fixing this fixes assumptions in other important drivers,
which is a net benefit for now.
to the unused kva in the pv memory block to thread a freelist through.
This allows us to free pages that used to be used for pv entry chunks
since we can now track holes in the kva memory block.
Idea from: ups
o Properly use rman(9) to manage resources. This eliminates the
need to puc-specific hacks to rman. It also allows devinfo(8)
to be used to find out the specific assignment of resources to
serial/parallel ports.
o Compress the PCI device "database" by optimizing for the common
case and to use a procedural interface to handle the exceptions.
The procedural interface also generalizes the need to setup the
hardware (program chipsets, program clock frequencies).
o Eliminate the need for PUC_FASTINTR. Serdev devices are fast by
default and non-serdev devices are handled by the bus.
o Use the serdev I/F to collect interrupt status and to handle
interrupts across ports in priority order.
o Sync the PCI device configuration to include devices found in
NetBSD and not yet merged to FreeBSD.
o Add support for Quatech 2, 4 and 8 port UARTs.
o Add support for a couple dozen Timedia serial cards as found
in Linux.
Remove the code to dyanmically change the pv_entry limits. Go back
to a single fixed kva reservation for pv entries, like was done
before when using the uma zone. Go back to never freeing pages
back to the free pool after they are no longer used, just like
before.
This stops the lock order reversal due to aquiring the kernel map
lock while pmap was locked.
This fixes the recursive panic if invariants are enabled.
The problem was that allocating/freeing kva causes vm_map_entry
nodes to be allocated/freed. That can recurse back into pmap as
new pages are hooked up to kvm and hence all the problem.
Allocating/freeing kva indirectly allocate/frees memory.
So, by going back to a single fixed size kva block and an index,
we avoid the recursion panics and the LOR.
The problem is that now with a linear block of kva, we have no
mechanism to track holes once pages are freed. UMA has the same
problem when using custom object for a zone and a fixed reservation
of kva. Simple solutions like having a bitmap would work, but would
be very inefficient when there are hundreds of thousands of bits
in the map. A first-free pointer is similarly flawed because pages
can be freed at random and the first-free pointer would be rewinding
huge amounts. If we could allocate memory for tree strucures or
an external freelist, that would work. Except we cannot allocate/free
memory here because we cannot allocate/free address space to use
it in. Anyway, my change here reverts back to the UMA behavior of
not freeing pages for now, thereby avoiding holes in the map.
ups@ had a truely evil idea that I'll investigate. It should allow
freeing unused pages again by giving us a no-cost way to track the
holes in the kva block. But in the meantime, this should get people
booting with witness and/or invariants again.
Footnote: amd64 doesn't have this problem because of the direct map
access method. I'd done all my witness/invariants testing there. I'd
never considered that the harmless-looking kmem_alloc/kmem_free calls
would cause such a problem and it didn't show up on the boot test.
entry (PTE) have the same meaning. The exception to this rule is the
eighth bit (0x080). It is the PS bit in a PDE and the PAT bit in a
PTE. This change avoids the possibility that pmap_enter() confuses a
PAT bit with a PS bit, avoiding a panic().
Eliminate a diagnostic printf() from the i386 pmap_enter() that serves
no current purpose, i.e., I've seen no bug reports in the last two
years that are helped by this printf().
Reviewed by: jhb
(i.e. no keyboard controller present), try two other common methods for
resetting i386 machine - pci reset and port 0x92 fast reset. Only if neither
works warn user and resort to "unmap entire address space and hope for good"
hack. This makes my MacBook Pro rebooting just fine and should also help
other legacy-free hardware out there.
Also, disable interrupts unconditionally in cpu_reset_real(), since we don't
want any interference.
MFC after: 1 week
per page = effectively 12.19 bytes per pv entry after overheads).
Instead of using a shared UMA zone for 24 byte pv entries (two 8-byte tailq
nodes, a 4 byte pointer, and a 4 byte address), we allocate a page at a
time per process. This provides 336 pv entries per process (actually, per
pmap address space) and eliminates one of the 8-byte tailq entries since
we now can track per-process pv entries implicitly. The pointer to
the pmap can be eliminated by doing address arithmetic to find the metadata
on the page headers to find a single pointer shared by all 336 entries.
There is an 11-int bitmap for the freelist of those 336 entries.
This is mostly a mechanical conversion from amd64, except:
* i386 has to allocate kvm and map the pages, amd64 has them outside of kvm
* native word size is smaller, so bitmaps etc become 32 bit instead of 64
* no dump_add_page() etc stuff because they are in kvm always.
* various pmap internals tweaks because pmap uses direct map on amd64 but
on i386 it has to use sched_pin and temporary mappings.
Also, sysctl vm.pmap.pv_entry_max and vm.pmap.shpgperproc are now
dynamic sysctls. Like on amd64, i386 can now tune the pv entry limits
without a recompile or reboot.
This is important because of the following scenario. If you have a 1GB
file (262144 pages) mmap()ed into 50 processes, that requires 13 million
pv entries. At 24 bytes per pv entry, that is 314MB of ram and kvm, while
at 12 bytes it is 157MB. A 157MB saving is significant.
Test-run by: scottl (Thanks!)
caches are dangerous" to "a shared L1 data cache is dangerous". This
is a compromise between paranoia and performance: Unlike the L1 cache,
nobody has publicly demonstrated a cryptographic side channel which
exploits the L2 cache -- this is harder due to the larger size, lower
bandwidth, and greater associativity -- and prohibiting shared L2
caches turns Intel Core Duo processors into Intel Core Solo processors.
As before, the 'machdep.hyperthreading_allowed' sysctl will allow even
the L1 data cache to be shared.
Discussed with: jhb, scottl
Security: See FreeBSD-SA-05:09.htt for background material.
Major differences:
* since there is no direct map region, there is no custom uma memory
allocator to modify to include its pages in the dumps.
* Various data entries are reduced from 64 bit to 32 bit to match the
native size.
dump_add_page() and dump_drop_page() are still present in case one wants to
arrange for arbitary pages to be dumped. This is of marginal use though
because libkvm+kgdb cannot address physical memory that isn't mapped into
kvm.
