The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
kernel gs base, because %rip is adjusted only on kernel-mode trap caused
by iretq execution. On the other hand, the stack contains (hardware
part of) trap frame from the usermode. As a consequence, checking for
frame mode and doing swapgs causes the kernel to enter trap() with
usermode gs base.
Remove the check for mode and conditional swapgs, we already have right
gs base in the MSR.
Submitted by: Nate Eldredge <neldredge math ucsd edu>
MFC after: 3 days
virtualization work done by Marko Zec (zec@).
This is the first in a series of commits over the course
of the next few weeks.
Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.
We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.
Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch
more mappings to the same physical page have different memory types, i.e.,
PAT settings. Consequently, if pmap_change_attr() is applied to a virtual
address range within the kernel map, then the corresponding ranges of the
direct map also need to be changed. Enhance pmap_change_attr() to handle
this case automatically.
Add a comment describing what pmap_change_attr() does.
Discussed with: jhb
features of CPUs like reading/writing machine-specific registers,
retrieving cpuid data, and updating microcode.
- Add cpucontrol(8) utility, that provides userland access to
the features of cpuctl(4).
- Add subsequent manpages.
The cpuctl(4) device operates as follows. The pseudo-device node cpuctlX
is created for each cpu present in the systems. The pseudo-device minor
number corresponds to the cpu number in the system. The cpuctl(4) pseudo-
device allows a number of ioctl to be preformed, namely RDMSR/WRMSR/CPUID
and UPDATE. The first pair alows the caller to read/write machine-specific
registers from the correspondent CPU. cpuid data could be retrieved using
the CPUID call, and microcode updates are applied via UPDATE.
The permissions are inforced based on the pseudo-device file permissions.
RDMSR/CPUID will be allowed when the caller has read access to the device
node, while WRMSR/UPDATE will be granted only when the node is opened
for writing. There're also a number of priv(9) checks.
The cpucontrol(8) utility is intened to provide userland access to
the cpuctl(4) device features. The utility also allows one to apply
cpu microcode updates.
Currently only Intel and AMD cpus are supported and were tested.
Approved by: kib
Reviewed by: rpaulo, cokane, Peter Jeremy
MFC after: 1 month
As clearly mentioned on the mailing lists, there is a list of drivers
that have not been ported to the MPSAFE TTY layer yet. Remove them from
the kernel configuration files. This means people can now still use
these drivers if they explicitly put them in their kernel configuration
file, which is good.
People should keep in mind that after August 10, these drivers will not
work anymore. Even though owners of the hardware are capable of getting
these drivers working again, I will see if I can at least get them to a
compilable state (if time permits).
pmap_change_attr() in order to use the direct map for any cache mode, not
just write-back mode.
It is worth noting that this change also eliminates a situation in which we
have two mappings to the same physical memory with different cache modes.
Submitted by: Magesh Dhasayyan (with some changes by me)
Discussed with: jhb
mode changes, and cache and TLB invalidation when some or all of the
specified range is already mapped with the specified cache mode.
Submitted by: Magesh Dhasayyan
the 32bit images on amd64.
Change the semantic of the PCB_32BIT pcb flag to request the context
switch code to operate on the segment registers. Its previous meaning
of saving or restoring the %gs base offset is assigned to the new
PCB_GS32BIT flag.
FreeBSD 32bit image activator sets the PCB_32BIT flag, while Linux 32bit
emulation sets PCB_32BIT | PCB_GS32BIT.
Reviewed by: peter
MFC after: 2 weeks
mapping to 4KB page mappings when the specified attribute change only
applies to a portion of the 2MB page. Previously, in such cases,
pmap_change_attr() gave up and returned an error.
Submitted by: Magesh Dhasayyan
The uart(4) driver has the advantage of supporting a wider variety of
hardware on a greater amount of platforms. This driver has already been
the standard on platforms such as ia64, powerpc and sparc64.
I've decided not to change anything on pc98. I'd rather let people from
the pc98 team look at this.
Approved by: philip (mentor), marcel
Initialize %ds, %es, and %fs during CPU startup. Otherwise a garbage
value could leak to a 32-bit process if a process migrated to a different
CPU after exec and the new CPU had never exec'd a 32-bit process.
A more complete fix is needed, but this mitigates the most frequent
manifestations.
Obtained from: ups
page directory pages from VM_MIN_KERNEL_ADDRESS through the end of the
kernel's bss. Specifically, the dependence was in pmap_growkernel()'s one-
time initialization of kernel_vm_end, not in its main body. (I could not,
however, resist the urge to optimize the main body.)
Reduce the number of preallocated page directory pages to just those needed
to support NKPT page table pages. (In fact, this allows me to revert a
couple of my earlier changes to create_pagetables().)
page table pages have to be preallocated ...'', violates an assumption made
by minidumpsys(): kernel_vm_end is the highest virtual address that has ever
been used by the kernel. Now, however, the kernel code, data, and bss may
reside at addresses beyond kernel_vm_end. This revision modifies the upper
bound on minidumpsys()'s two page table traversals to account for this
possibility.
to vm_page_alloc() instead of VM_ALLOC_SYSTEM. VM_ALLOC_SYSTEM was the
logical choice before FreeBSD 7.0 because VM_ALLOC_INTERRUPT could not
reclaim a cached page. Simply put, there was no ordering between
VM_ALLOC_INTERRUPT and VM_ALLOC_SYSTEM as to which "dug deeper" into the
cache and free queues. Now, there is; VM_ALLOC_INTERRUPT dominates
VM_ALLOC_SYSTEM.
While I'm here, teach pmap_growkernel() to request a prezeroed page.
MFC after: 1 week
ceiling as a fraction of the kernel map's size rather than an absolute
quantity. Thus, scaling of the kmem map's size will be automatic with
changes to the kernel map's size.
in practice, the error (currently) makes no difference because the computation
performed by KVADDR() hides the error. This revision fixes the error.
Also, eliminate a (now) unused definition.
maximum size of the kmem map can be greater than 4GB, there is little point
in making the kernel virtual address space larger than 6GB.
Tested by: kris@
Now that st_rdev is being automatically generated by the kernel, there
is no need to define static major/minor numbers for the iodev and
memdev. We still need the minor numbers for the memdev, however, to
distinguish between /dev/mem and /dev/kmem.
Approved by: philip (mentor)
KERNBASE and VM_MIN_KERNEL_ADDRESS are no longer the same, the physical
memory allocated during bootstrap will be offset from the low-end of the
kernel's page table.
address space on the amd64 architecture. The amd64 architecture
requires kernel code and global variables to reside in the highest 2GB
of the 64-bit virtual address space. Thus, KERNBASE cannot change.
However, KERNBASE is sometimes used as the start of the kernel virtual
address space. Henceforth, VM_MIN_KERNEL_ADDRESS should be used
instead. Since KERNBASE and VM_MIN_KERNEL_ADDRESS are still the same
address, there should be no visible effect from this change (yet).
That said, kris@ has tested crash dumps under the full patch that
increases the kernel virtual address space on amd64 to 6GB.
Tested by: kris@
address space on the amd64 architecture. The amd64 architecture
requires kernel code and global variables to reside in the highest 2GB
of the 64-bit virtual address space. Thus, KERNBASE cannot change.
However, KERNBASE is sometimes used as the start of the kernel virtual
address space. Henceforth, VM_MIN_KERNEL_ADDRESS should be used
instead. Since KERNBASE and VM_MIN_KERNEL_ADDRESS are still the same
address, there should be no visible effect from this change (yet).
before PG_M. This sometimes prevents unnecessary removal of write access
from a PTE. Overall, the net result is fewer demotions and promotion
failures.
page table page. The direction of the traversal can matter if
pmap_promote_pde() has to remove write access (PG_RW) from a PTE that hasn't
been modified (PG_M). In general, if there are two or more such PTEs to
choose among, it is better to write protect the one nearer the high end of
the page table page rather than the low end. This is because most programs
access memory in an ascending direction. The net result of this change is a
sometimes significant reduction in the number of failed promotion attempts
and the number of pages that are write protected by pmap_promote_pde().
promotion within the kernel's address space. Specifically,
pmap_promote_pde() is only called when the page table page (PTP) that
is referenced by the given PDE has a full "use count", i.e., its
wire_count is 512. Although this guarantees for a user address space
that all 512 PTEs in the PTP hold valid mappings, the same is not true
of the kernel's address space. A kernel PTP always has a use count of
512 regardless of the state of the PTEs. Therefore,
pmap_promote_pde() should not assume (or assert) that the first PTE in
the PTP is valid.
parts relied on the now removed NET_NEEDS_GIANT.
Most of I4B has been disconnected from the build
since July 2007 in HEAD/RELENG_7.
This is what was removed:
- configuration in /etc/isdn
- examples
- man pages
- kernel configuration
- sys/i4b (drivers, layers, include files)
- user space tools
- i4b support from ppp
- further documentation
Discussed with: rwatson, re
what Linux does. This is because robust futexes are mostly
userspace thing which we cannot alter. Two syscalls maintain
pointer to userspace list and when process exits a routine
walks this list waking up processes sleeping on futexes
from that list.
Reviewed by: kib (mentor)
MFC after: 1 month
from idle over the next tick.
- Add a new MD routine, cpu_wake_idle() to wakeup idle threads who are
suspended in cpu specific states. This function can fail and cause the
scheduler to fall back to another mechanism (ipi).
- Implement support for mwait in cpu_idle() on i386/amd64 machines that
support it. mwait is a higher performance way to synchronize cpus
as compared to hlt & ipis.
- Allow selecting the idle routine by name via sysctl machdep.idle. This
replaces machdep.cpu_idle_hlt. Only idle routines supported by the
current machine are permitted.
Sponsored by: Nokia
for better structure.
Much of this is related to <sys/clock.h>, which should really have
been called <sys/calendar.h>, but unless and until we need the name,
the repocopy can wait.
In general the kernel does not know about minutes, hours, days,
timezones, daylight savings time, leap-years and such. All that
is theoretically a matter for userland only.
Parts of kernel code does however care: badly designed filesystems
store timestamps in local time and RTC chips almost universally
track time in a YY-MM-DD HH:MM:SS format, and sometimes in local
timezone instead of UTC. For this we have <sys/clock.h>
<sys/time.h> on the other hand, deals with time_t, timeval, timespec
and so on. These know only seconds and fractions thereof.
Move inittodr() and resettodr() prototypes to <sys/time.h>.
Retain the names as it is one of the few surviving PDP/VAX references.
Move startrtclock() to <machine/clock.h> on relevant platforms, it
is a MD call between machdep.c/clock.c. Remove references to it
elsewhere.
Remove a lot of unnecessary <sys/clock.h> includes.
Move the machdep.disable_rtc_set sysctl to subr_rtc.c where it belongs.
XXX: should be kern.disable_rtc_set really, it's not MD.
Note this includes changes to all drivers and moves some device firmware
loading to use firmware(9) and a separate module (e.g. ral). Also there
no longer are separate wlan_scan* modules; this functionality is now
bundled into the wlan module.
Supported by: Hobnob and Marvell
Reviewed by: many
Obtained from: Atheros (some bits)
noise from sio per unit. sio likes to probe if interrupts are configured
correctly by looking at the pending bits of the atpic in order to put a
non-fatal warning on the console. I think I'd rather read the pending
bits from the apics, but I'm not sure its worth the hassle.
lookup hard interrupt events by number. Ignore the irq# for soft intrs.
- Add support to cpuset for binding hardware interrupts. This has the
side effect of binding any ithread associated with the hard interrupt.
As per restrictions imposed by MD code we can only bind interrupts to
a single cpu presently. Interrupts can be 'unbound' by binding them
to all cpus.
Reviewed by: jhb
Sponsored by: Nokia
2/4MB page from a PDE. Specifically, change it to use PG_PS_FRAME,
not PG_FRAME, to extract the physical address of a 2/4MB page from a
PDE.
Change the last argument passed to pmap_pv_insert_pde() from a
vm_page_t representing the first 4KB page of a 2/4MB page to the
vm_paddr_t of the 2/4MB page. This avoids an otherwise unnecessary
conversion from a vm_paddr_t to a vm_page_t in pmap_copy().
allows all the INTR_FILTER #ifdef's to be removed from the MD interrupt
code.
- Rename the intr_event 'eoi', 'disable', and 'enable' hooks to
'post_filter', 'pre_ithread', and 'post_ithread' to be less x86-centric.
Also, add a comment describe what the MI code expects them to do.
- On amd64, i386, and powerpc this is effectively a NOP.
- On arm, don't bother masking the interrupt unless the ithread is
scheduled in the non-INTR_FILTER case to match what INTR_FILTER did.
Also, don't bother unmasking the interrupt in the post_filter case if
we never masked it. The INTR_FILTER case had been doing this by having
arm_unmask_irq for the post_filter (formerly 'eoi') hook.
- On ia64, stray interrupts are now masked for the non-INTR_FILTER case.
They were already masked in the INTR_FILTER case.
- On sparc64, use the a NULL pre_ithread hook and use intr_enable_eoi() for
both the 'post_filter' and 'post_ithread' hooks to match what the
non-INTR_FILTER code did.
- On sun4v, retire the ithread wrapper hack by using an appropriate
'post_ithread' hook instead (it's what 'post_ithread'/'enable' was
designed to do even in 5.x).
Glanced at by: piso
Reviewed by: marius
Requested by: marius [1], [5]
Tested on: amd64, i386, arm, sparc64
given pmap is never NULL, and therefore pmap_pml4e() can never return
NULL. The pervasive use of these inline functions throughout the pmap
makes these simple changes worthwhile.
to detect (or load) kernel NLM support in rpc.lockd. Remove the '-k'
option to rpc.lockd and make kernel NLM the default. A user can still
force the use of the old user NLM by building a kernel without NFSLOCKD
and/or removing the nfslockd.ko module.
frequency generation and what frequency the generated was anyones
guess.
In general the 32.768kHz RTC clock x-tal was the best, because that
was a regular wrist-watch Xtal, whereas the X-tal generating the
ISA bus frequency was much lower quality, often costing as much as
several cents a piece, so it made good sense to check the ISA bus
frequency against the RTC clock.
The other relevant property of those machines, is that they
typically had no more than 16MB RAM.
These days, CPU chips croak if their clocks are not tightly within
specs and all necessary frequencies are derived from the master
crystal by means if PLL's.
Considering that it takes on average 1.5 second to calibrate the
frequency of the i8254 counter, that more likely than not, we will
not actually use the result of the calibration, and as the final
clincher, we seldom use the i8254 for anything besides BEL in
syscons anyway, it has become time to drop the calibration code.
If you need to tell the system what frequency your i8254 runs,
you can do so from the loader using hw.i8254.freq or using the
sysctl kern.timecounter.tc.i8254.frequency.
these days, so de-generalize the acquire_timer/release_timer api
to just deal with speakers.
The new (optional) MD functions are:
timer_spkr_acquire()
timer_spkr_release()
and
timer_spkr_setfreq()
the last of which configures the timer to generate a tone of a given
frequency, in Hz instead of 1/1193182th of seconds.
Drop entirely timer2 on pc98, it is not used anywhere at all.
Move sysbeep() to kern/tty_cons.c and use the timer_spkr*() if
they exist, and do nothing otherwise.
Remove prototypes and empty acquire-/release-timer() and sysbeep()
functions from the non-beeping archs.
This eliminate the need for the speaker driver to know about
i8254frequency at all. In theory this makes the speaker driver MI,
contingent on the timer_spkr_*() functions existing but the driver
does not know this yet and still attaches to the ISA bus.
Syscons is more tricky, in one function, sc_tone(), it knows the hz
and things are just fine.
In the other function, sc_bell() it seems to get the period from
the KDMKTONE ioctl in terms if 1/1193182th second, so we hardcode
the 1193182 and leave it at that. It's probably not important.
Change a few other sysbeep() uses which obviously knew that the
argument was in terms of i8254 frequency, and leave alone those
that look like people thought sysbeep() took frequency in hertz.
This eliminates the knowledge of i8254_freq from all but the actual
clock.c code and the prof_machdep.c on amd64 and i386, where I think
it would be smart to ask for help from the timecounters anyway [TBD].
are mixed. Some pure context switch microbenchmarks show up to 29%
improvement. Pipe based context switch microbenchmarks show up to 7%
improvement. Real world tests are far less impressive as they are
dominated more by actual work than switch overheads, but depending on
the machine in question, workload, kernel options, phase of moon, etc, a
few percent gain might be seen.
Summary of changes:
- don't reload MSR_[FG]SBASE registers when context switching between
non-threaded userland apps. These typically cost 120 clock cycles each
on an AMD cpu (less on Barcelona/Phenom). Intel cores are probably no
faster on this.
- The above change only helps unthreaded userland apps that tend to use
the same value for gsbase. Threaded apps will get no benefit from this.
- reorder things like accessing the pcb to be in memory order, to give
prefetching a better chance of working. Operations are now in increasing
memory address order, rather than reverse or random.
- Push some lesser used code out of the main code paths. Hopefully
allowing better code density in cache lines. This is probably futile.
- (part 2 of previous item) Reorder code so that branches have a more
realistic static branch prediction hint. Both Intel and AMD cpus
default to predicting branches to lower memory addresses as being
taken, and to higher memory addresses as not being taken. This is
overridden by the limited dynamic branch prediction subsystem. A trip
through userland might overflow this.
- Futule attempt at spreading the use of the results of previous operations
in new operations. Hopefully this will allow the cpus to execute in
parallel better.
- stop wasting 16 bytes at the top of kernel stack, below the PCB.
- Never load the userland fs/gsbase registers for kthreads, but preserve
curpcb->pcb_[fg]sbase as caches for the cpu. (Thanks Jeff!)
Microbenchmarking this code seems to be really sensitive to things like
scheduling luck, timing, cache behavior, tlb behavior, kernel options,
other random code changes, etc.
While it doesn't help heavy userland workloads much, it does help high
context switch loads a little, and should help those that involve
switching via kthreads a bit more.
A special thanks to Kris for the testing and reality checks, and Jeff for
tormenting me into doing this. :)
This is still work-in-progress.
PTE if that PTE has the PG_RW bit set. However, this assumption does
not hold on recent processors from Intel. For example, consider a PTE
that has the PG_RW bit set but the PG_M bit clear. Suppose this PTE
is cached in the TLB and later the PG_RW bit is cleared in the PTE,
but the corresponding TLB entry is not (yet) invalidated.
Historically, upon a write access using this (stale) TLB entry, the
TLB would observe that the PG_RW bit had been cleared and initiate a
page fault, aborting the setting of the PG_M bit in the PTE. Now,
however, P4- and Core2-family processors will set the PG_M bit before
observing that the PG_RW bit is clear and initiating a page fault. In
other words, the write does not occur but the PG_M bit is still set.
The real impact of this difference is not that great. Specifically,
we should no longer assert that any PTE with the PG_M bit set must
also have the PG_RW bit set, and we should ignore the state of the
PG_M bit unless the PG_RW bit is set. However, these changes enable
me to remove a work-around from pmap_promote_pde(), the superpage
promotion procedure.
(Note: The AMD processors that we have tested, including the latest,
the Phenom, still exhibit the historical behavior.)
Acknowledgments: After I observed the problem, Stephan (ups) was
instrumental in characterizing the exact behavior of Intel's recent
TLBs.
Tested by: Peter Holm
The overflow causes the wraparound with consequent corruption of the
(almost) whole address space mapping.
As Alan noted, pmap_copy() does not require the wrap-around checks
because it cannot be applied to the kernel's pmap. The checks there are
included for consistency.
Reported and tested by: kris (i386/pmap.c:pmap_remove() part)
Reviewed by: alc
MFC after: 1 week
lock in the 8259A drivers as these drivers are only used on UP systems.
This slightly reduces the penalty of an SMP kernel (such as GENERIC) on
a UP x86 machine.
resource to a CPU. The default method is to pass the request up to the
parent similar to BUS_CONFIG_INTR() so that all busses don't have to
explicitly implement bus_bind_intr. A bus_bind_intr(9) wrapper routine
similar to bus_setup/teardown_intr() is added for device drivers to use.
Unbinding an interrupt is done by binding it to NOCPU. The IRQ resource
must be allocated, but it can happen in any order with respect to
bus_setup_intr(). Currently it is only supported on amd64 and i386 via
nexus(4) methods that simply call the intr_bind() routine.
Tested by: gallatin
- Always include the ie_disable and ie_eoi methods in 'struct intr_event'
and collapse down to one intr_event_create() routine. The disable and
eoi hooks simply aren't used currently in the !INTR_FILTER case.
- Expand 'disab' to 'disable' in a few places.
- Use function casts for arm and i386:intr_eoi_src() instead of wrapper
routines since to trim one extra indirection.
Compiled on: {arm,amd64,i386,ia64,ppc,sparc64} x {FILTER, !FILTER}
Tested on: {amd64,i386} x {FILTER, !FILTER}
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.
MFC after: 1 month
Discussed with: imp, rink
- Add a new intr_event method ie_assign_cpu() that is invoked when the MI
code wishes to bind an interrupt source to an individual CPU. The MD
code may reject the binding with an error. If an assign_cpu function
is not provided, then the kernel assumes the platform does not support
binding interrupts to CPUs and fails all requests to do so.
- Bind ithreads to CPUs on their next execution loop once an interrupt
event is bound to a CPU. Only shared ithreads are bound. We currently
leave private ithreads for drivers using filters + ithreads in the
INTR_FILTER case unbound.
- A new intr_event_bind() routine is used to bind an interrupt event to
a CPU.
- Implement binding on amd64 and i386 by way of the existing pic_assign_cpu
PIC method.
- For x86, provide a 'intr_bind(IRQ, cpu)' wrapper routine that looks up
an interrupt source and binds its interrupt event to the specified CPU.
MI code can currently (ab)use this by doing:
intr_bind(rman_get_start(irq_res), cpu);
however, I plan to add a truly MI interface (probably a bus_bind_intr(9))
where the implementation in the x86 nexus(4) driver would end up calling
intr_bind() internally.
Requested by: kmacy, gallatin, jeff
Tested on: {amd64, i386} x {regular, INTR_FILTER}
receivers from being given interrupts if any CPUs in the system were not
tagged as interrupt receivers that I introduced when switching the x86
interrupt code to track CPUs via FreeBSD CPU IDs rather than local APIC
IDs. In practice this only affects systems with Hyperthreading (though
disabling HTT in the BIOS would workaround the issue) as that is the only
case currently where one can have CPUs that aren't tagged as interrupt
receivers. On a Dell SC1425 test box with 2 x Xeon w/ HTT (so 4 logical
CPUs of which 2 were interrupt receivers) the result was that all
device interrupts were sent to CPU 0.
MFC after: 1 week
Pointy hat to: jhb
different "platforms" on x86 machines. The existing code already handles
having two platforms: ACPI and legacy. However, the existing approach was
rather hardcoded and difficult to extend. These changes take the approach
that each x86 hardware platform should provide its own nexus(4) driver (it
can inherit most of its behavior from the default legacy nexus(4) driver)
which is responsible for probing for the platform and performing
appropriate platform-specific setup during attach (such as adding a
platform-specific bus device). This does mean changing the x86 platform
busses to no longer use an identify routine for probing, but to move that
logic into their matching nexus(4) driver instead.
- Make the default nexus(4) driver in nexus.c on i386 and amd64 handle the
legacy platform. It's probe routine now returns BUS_PROBE_GENERIC so it
can be overriden.
- Expose a nexus_init_resources() routine which initializes the various
resource managers so that subclassed nexus(4) drivers can invoke it from
their attach routine.
- The legacy nexus(4) driver explicitly adds a legacy0 device in its
attach routine.
- The ACPI driver no longer contains an new-bus identify method. Instead
it exposes a public function (acpi_identify()) which is a probe routine
that the MD nexus(4) drivers can use to probe for ACPI. All of the
probe logic in acpi_probe() is now moved into acpi_identify() and
acpi_probe() is just a stub.
- On i386 and amd64, an ACPI-specific nexus(4) driver checks for ACPI via
acpi_identify() and claims the nexus0 device if the probe succeeds. It
then explicitly adds an acpi0 device in its attach routine.
- The legacy(4) driver no longer knows anything about the acpi0 device.
- On ia64 if acpi_identify() fails you basically end up with no devices.
This matches the previous behavior where the old acpi_identify() would
fail to add an acpi0 device again leaving you with no devices.
Discussed with: imp
Silence on: arch@
ABI and the direction flag, that is it now assumes that the direction
flag is cleared at the entry of a function and it doesn't clear once
more if needed. This new behaviour conforms to the i386/amd64 ABI.
Modify the signal handler frame setup code to clear the DF {e,r}flags
bit on the amd64/i386 for the signal handlers.
jhb@ noted that it might break old apps if they assumed DF == 1 would be
preserved in the signal handlers, but that such apps should be rare and
that older versions of gcc would not generate such apps.
Submitted by: Aurelien Jarno <aurelien aurel32 net>
PR: 121422
Reviewed by: jhb
MFC after: 2 weeks
PhysMask fields based on the number of physical address bits supported
by the current CPU. The old code assumed 36 bits on i386 and 40 bits on
amd64. In truth, all Intel CPUs up until recently used 36 bits (a newer
Intel CPU uses 38 bits) and all the Opteron CPUs used 40 bits.
In at least one case (the new Intel CPU) having the size of the mask field
wrong resulted in writing questionable values into the MTRR registers on
the application processors (BSP as well if you modify the MTRRs via
memcontrol or running X, etc.). The result of the questionable physmask
was that all of memory was apparently treated as uncached rather than
write-back resulting in a very significant performance hit.
Fix this by constructing a run-time mask for the PhysBase and PhysMask
fields based on the number of physical address bits supported by the CPU.
All 64-bit capable CPUs provide a count of PA bits supported via the
0x80000008 extended CPUID feature, so use that if it is available. If that
feature is not available, then assume 36 PA bits.
While I'm here, expand the (now-unused) macros for the PhysBase and
PhysMask fields to the current largest possible value (52 PA bits).
MFC after: 1 week
PR: i386/120516
Reported by: Nokia
While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential. Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.
the cpufreq drivers to reliably use properties of PCI devices for quirks,
etc.
- For the legacy drivers, add CPU devices via an identify routine in the
CPU driver itself rather than in the legacy driver's attach routine.
- Add CPU devices after Host-PCI bridges in the acpi bus driver.
- Change the ichss(4) driver to use pci_find_bsf() to locate the ICH and
check its device ID rather than having a bogus PCI attachment that only
checked for the ID in probe and always failed. As a side effect, you
can now kldload ichss after boot.
- Fix the ichss(4) driver to use the correct device_t for the ICH (and not
for ichss0) when doing PCI config space operations to enable SpeedStep.
MFC after: 2 weeks
Reviewed by: njl, Andriy Gapon avg of icyb.net.ua
mappings. Automatic promotion can be enabled by setting the tunable
"vm.pmap.pg_ps_enabled" to a non-zero value. By default, automatic
promotion is disabled. (Expect this to change.)
Reviewed by: ups
Tested by: kris, Peter Holm
tree structure that encodes the level of cache sharing and other
properties.
- Provide several convenience functions for creating one and two level
cpu trees as well as a default flat topology. The system now always
has some topology.
- On i386 and amd64 create a seperate level in the hierarchy for HTT
and multi-core cpus. This will allow the scheduler to intelligently
load balance non-uniform cores. Presently we don't detect what level
of the cache hierarchy is shared at each level in the topology.
- Add a mechanism for testing common topologies that have more information
than the MD code is able to provide via the kern.smp.topology tunable.
This should be considered a debugging tool only and not a stable api.
Sponsored by: Nokia
PAGE_SIZE or less, the bounce page counting logic was flawed and wouldn't
reserve any pages. Adjust to be correct. Review of other architectures is
forthcoming.
Submitted by: Joseph Golio
aligned (or at least not cross a page boundary). However, it turns out
that on at least one machine one table header does cross a page boundary.
This caused problems with the MADT early probe as it uses the crash dump
map to load ACPI tables by loading the RSDT/XSDT into pages 1 ... N and
loading the header of each ACPI table header into page 0 looking for the
MADT. However, if a table header crossed a page boundary, then page 1
would get trashed resulting in a panic. Fix this by reserving the first
2 pages for ACPI table headers (headers are less than a page in size,
so 2 pages will be sufficient) and use pages 2 .. N for the RSDT and XSDT.
Note: amd64 should probably be simplified to just use pmap_mapbios()
for all these tables which will use the direct map and not need the
crash dump hack.
MFC after: 5 days
Tested on: i386
Reported by: Pete French petefrench of ticketswitch.com
compiled under PMAP_DIAGNOSTIC are now KASSERT()s. (Note: The kernel
option DIAGNOSTIC still disables inlining of certain pmap functions.)
Eliminate dead code from pmap_enter(). This code implemented an assertion.
On i386, an equivalent check is already implemented. However, on amd64,
a small change is required to implement an equivalent check.
Eliminate \n from a nearby panic string.
Use KASSERT() to reimplement pmap_copy()'s two assertions.
in the range and precision of their type(s) on amd64, but FLT_EVAL_METHOD
said that they were evalated in the "interesting" (buggy) i387 methods.
float_t was broken compatibly with FLT_EVAL_METHOD.
These definitions seem to be broken on powerpc and possibly on arm.
float_t is float on powerpc with gcc [-notraditional] according to
glibc, and FLT_EVAL_METHOD is marked with XXX on arm.
the kernel's direct map instead of the pmap's recursive mapping to access
the lowest level in the page table. The direct map is preferable for two
reasons: (1) The TLB is more likely to hold the required direct mapping
because pmap_enter() has already used the direct map to access a nearby
PTE and (2) loading a direct mapping into the TLB involves walking only 2
or 3 levels of the page table instead of 4.
Unmasked exceptions (which can be fixed up using fpset*() before they
trap) are very rare, especially on amd64 since SSE exceptions trap
synchronously, but I want to merge the faster amd64 implementations of
fpset*() back to i386 without introducing the bug on i386.
The i386 implementation has always avoided the trap automatically by
changing things using load/store of the FP environment, but this is
very slow. Most changes only affect the control word, so they can
usually be done much more efficiently, and amd64 has always done this,
but loading the control word can trap.
This version use the fast method only in the usual case where it will
not trap. This only costs a couple of integer instructions (including
one branch which I haven't optimized carefully yet) in the usual case,
but bloats the inlines a lot. The inlines were already a bit too large
to handle both the FPU and SSE.
- fix a previous style fix: shifts should be in the correct direction even
if they are null.
- restore a comment about namespace pollution from floatingpoint.h 1.12 and
update it.
- remove unused namespace pollution FP_*REG.
- improve some comments.
- sort macro definitions for entry points.
- don't use underscores for macro args.
- fix this to compile with C++ by casting ints to enums in a few places
and by using the correct parameter type for _fpsetprec(). Remove
__cplusplus ifdefs which disabled the buggy code.
- remove __CC_SUPPORTS___INLINE ifdefs. `__inline' vs `inline', and either
of these #defined away, are supposed to be handled by very old ifdefs
in <sys/cdefs.h>. Thus the __CC_SUPPORTS___INLINE macro is not needed
here (or anywhere else that it used). It is less needed here than in
most places, since this file is userland-only and userland is far from
supporting INTEL_COMPILER. The __CC_SUPPORTS___INLINE__ macro which
was used here is even less needed. It is to support spelling `inline'
as `__inline__' instead of the usual spelling `__inline'.
Fix some style bugs that I missed in the previous commit (remove unused
asms and sort more variables).
pv_list_count from struct md_page. Ever since Peter rewrote the pv
entry allocator for amd64 and i386 pv_list_count has been correctly
maintained but otherwise unused.
instead of writing apologetic comments. As it turns out, I need every
kernel page table page to have a legitimate pindex to support superpage
promotion on kernel memory.
Correct a nearby style error: Pointers should be compared to NULL.
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.
Assign approximate why values to all current consumers of the
kdb_enter() interface.
cards:
o RocketRAID 172x series
o RocketRAID 174x series
o RocketRAID 2210
o RocketRAID 222x series
o RocketRAID 2240
o RocketRAID 230x series
o RocketRAID 231x series
o RocketRAID 232x series
o RocketRAID 2340
o RocketRAID 2522
Many thanks to Highpoint for their continued support of FreeBSD.
Submitted by: Highpoint
register (MacBooks only).
This allows MacBooks to boot in SMP mode without any trick and solves
the timer problems with HZ=1000.
MFC after: 1 week
Reviewed by: njl (mentor), jhb
Approved by: njl (mentor), jhb
with insufficient protection mode.
For the i386 and amd64, create the tunable, machdep.prot_fault_translation,
with the following behaviour:
0 = autodetect the signal to be delivered on KERN_PROTECTION_FAILURE
from vm_fault based on the ELF OSABI note:
no note or __FreeBSD_version < 700004 - SIGBUS/BUS_PAGE_FAULT
note, and __FreeBSD_version >= 700004 - SIGSEGV/SEGV_ACCERR
1 = always SIGBUS/BUS_PAGE_FAULT
2 = always SIGSEGV/SEGV_ACCERR
This would do mostly automatic correction of ABI breakage, with the exception
of the untaged binaries for 7-CURRENT/RELENG_7 before the note is fixed. For
them, sysctl would allow to run the binary with manual settings.
Discussed with: portmgr (kris)
PR: kern/118304
MFC after: 3 days
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
allocation fails and pv entries are reclaimed, there may be an unused pv
entry in a pv chunk that survived the reclamation. However, previously,
after reclamation, get_pv_entry() did not look for an unused pv entry in
a surviving pv chunk; it simply retried the page allocation. Now, it
does look for an unused pv entry before retrying the page allocation.
Note: This only applies to RELENG_7. Earlier branches use a different
pv entry allocator.
MFC after: 6 weeks
since the branch caches on at least Athlon XP through Athlon 64 CPU's
don't understand such instructions and guarantee a cache miss taking
at least 10 cycles. Use the documented workaround "ret $0" instead
("nop; ret" also works, but "ret $0" is probably faster on old CPUs).
Normal code (even asm code) doesn't branch to "ret", since there is
usually some cleanup to do, but the __mcount, .mcount and .mexitcount
entry points were optimized too well to have the minimum number of
instructions (3 instructions each if profiling is not enabled) and
they did this. I didn't see a significant number of cache misses for
.mexitcount, but for the shared "ret" for __mcount and .mcount I
observed cache misses costing 26 cycles each. For a send(2) syscall
that makes about 70 function calls, the cost of these cache misses
alone increased the syscall time from about 4000 cycles to about 7000
cycles. 4000 is for a profiling (GUPROF) kernel with profiling disabled;
after this fix, configuring profiling only costs about 600 cycles in the
4000, which is consistent with almost perfect branch prediction in the
mcounting calls.
unused except to obfuscate disassemblies. -mprofiler-epilogue is
currently with gcc-4 (it does too little), but -finstrument-functions
is broken in a different way (it does too much).
amd64 version: meger whitespace fixes from i386 version.
- On amd64, just assume type #1 is always used. PCI 2.0 mandated
deprecated type #2 and required type #1 for all future bridges which
was well before amd64 existed.
- For i386, ignore whatever value was in 0xcf8 before testing for type #1
and instead rely on the other tests to determine if type #1 works. Some
newer machines leave garbage in 0xcf8 during boot and as a result the
kernel doesn't find PCI at all (which greatly confuses ACPI which expects
PCI to exist when PCI busses are in the namespace).
MFC after: 3 days
Discussed with: scottl
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.
Please don't forget to update your own custom config kernel files.
Approved by: cognet, marcel (maintainers of arches where option is
not enabled at the moment)
routine. It is not needed as the existing tests for segment coalescing
already handle bounced addresses and it prevents legal segment coalescing
in certain edge cases.
MFC after: 1 week
Reviewed by: scottl
include the ithread scheduling step. Without this, a preemption might
occur in between the interrupt getting masked and the ithread getting
scheduled. Since the interrupt handler runs in the context of curthread,
the scheudler might see it as having a such a low priority on a busy system
that it doesn't get to run for a _long_ time, leaving the interrupt stranded
in a disabled state. The only way that the preemption can happen is by
a fast/filter handler triggering a schduling event earlier in the handler,
so this problem can only happen for cases where an interrupt is being
shared by both a fast/filter handler and an ithread handler. Unfortunately,
it seems to be common for this sharing to happen with network and USB
devices, for example. This fixes many of the mysterious TCP session
timeouts and NIC watchdogs that were being reported. Many thanks to Sam
Lefler for getting to the bottom of this problem.
Reviewed by: jhb, jeff, silby
First, a file is mmap(2)ed and then mlock(2)ed. Later, it is truncated.
Under "normal" circumstances, i.e., when the file is not mlock(2)ed, the
pages beyond the EOF are unmapped and freed. However, when the file is
mlock(2)ed, the pages beyond the EOF are unmapped but not freed because
they have a non-zero wire count. This can be a mistake. Specifically,
it is a mistake if the sole reason why the pages are wired is because of
wired, managed mappings. Previously, unmapping the pages destroys these
wired, managed mappings, but does not reduce the pages' wire count.
Consequently, when the file is unmapped, the pages are not unwired
because the wired mapping has been destroyed. Moreover, when the vm
object is finally destroyed, the pages are leaked because they are still
wired. The fix is to reduce the pages' wired count by the number of
wired, managed mappings destroyed. To do this, I introduce a new pmap
function pmap_page_wired_mappings() that returns the number of managed
mappings to the given physical page that are wired, and I use this
function in vm_object_page_remove().
Reviewed by: tegge
MFC after: 6 weeks
- Populate the register values for the trapframe put on the stack by the
double fault handler.
- Teach DDB's trace routine to treat a double fault like other trap frames.
MFC after: 3 days
communicate that it relates to (is called by) thread_alloc()
o Add cpu_thread_free() which is called from thread_free()
to counter-act cpu_thread_alloc().
i386: Have cpu_thread_free() call cpu_thread_clean() to
preserve behaviour.
ia64: Have cpu_thread_free() call mtx_destroy() for the
mutex initialized in cpu_thread_alloc().
PR: ia64/118024
opposed to what process. Since threads by default have teh name of the
process unless over-written with more useful information, just print the
thread name instead.
This includes:
o mtree (for legal/intel_wpi)
o manpage for i386/amd64 archs
o module for i386/amd64 archs
o NOTES for i386/amd64 archs
Approved by: mlaier (comentor)
must be globally performed before calling any of the TLB invalidation
functions.
With one exception, on amd64, this requirement was already met. Fix this
one case. Also, as a clarification, change an existing atomic op into a
release. (Suggested by: jhb)
Reported and reviewed by: ups
MFC after: 3 days
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.
As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.
The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).
In collaboration with: Peter Holm
Reviewed by: jhb
warnings. Specifically, whenever vm_page_alloc(9) returned NULL to
get_pv_entry(), we issued a warning regardless of the number of pv
entries in use. (Note: The older pv entry allocator in RELENG_6 does
not have this problem.)
Reported by: Jeremy Chadwick
Eliminate the direct call to pagedaemon_wakeup() by get_pv_entry().
This was a holdover from earlier times when the page daemon was
responsible for the reclamation of pv entries.
MFC after: 5 days
refactored it to be a generic device.
Instead of being part of the standard kernel, there is now a 'nvram' device
for i386/amd64. It is in DEFAULTS like io and mem, and can be turned off
with 'nodevice nvram'. This matches the previous behavior when it was
first committed.
support machines having multiple independently numbered PCI domains
and don't support reenumeration without ambiguity amongst the
devices as seen by the OS and represented by PCI location strings.
This includes introducing a function pci_find_dbsf(9) which works
like pci_find_bsf(9) but additionally takes a domain number argument
and limiting pci_find_bsf(9) to only search devices in domain 0 (the
only domain in single-domain systems). Bge(4) and ofw_pcibus(4) are
changed to use pci_find_dbsf(9) instead of pci_find_bsf(9) in order
to no longer report false positives when searching for siblings and
dupe devices in the same domain respectively.
Along with this change the sole host-PCI bridge driver converted to
actually make use of PCI domain support is uninorth(4), the others
continue to use domain 0 only for now and need to be converted as
appropriate later on.
Note that this means that the format of the location strings as used
by pciconf(8) has been changed and that consumers of <sys/pciio.h>
potentially need to be recompiled.
Suggested by: jhb
Reviewed by: grehan, jhb, marcel
Approved by: re (kensmith), jhb (PCI maintainer hat)
ways:
(1) Cached pages are no longer kept in the object's resident page
splay tree and memq. Instead, they are kept in a separate per-object
splay tree of cached pages. However, access to this new per-object
splay tree is synchronized by the _free_ page queues lock, not to be
confused with the heavily contended page queues lock. Consequently, a
cached page can be reclaimed by vm_page_alloc(9) without acquiring the
object's lock or the page queues lock.
This solves a problem independently reported by tegge@ and Isilon.
Specifically, they observed the page daemon consuming a great deal of
CPU time because of pages bouncing back and forth between the cache
queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of
this problem turned out to be a deadlock avoidance strategy employed
when selecting a cached page to reclaim in vm_page_select_cache().
However, the root cause was really that reclaiming a cached page
required the acquisition of an object lock while the page queues lock
was already held. Thus, this change addresses the problem at its
root, by eliminating the need to acquire the object's lock.
Moreover, keeping cached pages in the object's primary splay tree and
memq was, in effect, optimizing for the uncommon case. Cached pages
are reclaimed far, far more often than they are reactivated. Instead,
this change makes reclamation cheaper, especially in terms of
synchronization overhead, and reactivation more expensive, because
reactivated pages will have to be reentered into the object's primary
splay tree and memq.
(2) Cached pages are now stored alongside free pages in the physical
memory allocator's buddy queues, increasing the likelihood that large
allocations of contiguous physical memory (i.e., superpages) will
succeed.
Finally, as a result of this change long-standing restrictions on when
and where a cached page can be reclaimed and returned by
vm_page_alloc(9) are eliminated. Specifically, calls to
vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and
return a formerly cached page. Consequently, a call to malloc(9)
specifying M_NOWAIT is less likely to fail.
Discussed with: many over the course of the summer, including jeff@,
Justin Husted @ Isilon, peter@, tegge@
Tested by: an earlier version by kris@
Approved by: re (kensmith)
In particular:
- smp_tlb_mtx is no longer used, so it is axed.
- smp rendezvous lock isn't really a leaf spin-mutex. Its bad placement in
the table, however, has been the source of a false positive LOR reporting
with the dt_lock. However, smp rendezvous lock would have had sched_lock
there for older lock, so it wasn't still a leaf lock.
- allpmaps is only used in ia32 architecture, so it is inserted in the
appropriate stub.
Addictionally:
- kse_zombie_lock is no longer present, so its definition is axed out.
- zombie_lock doesn't need to have an exported symbol, so just let's it be
declared as static.
Tested by: kris
Approved by: jeff (mentor)
Approved by: re
Together with the sys/i386/i386/trap.c rev. 1.306 it fixes the PR.
Submitted by: rdivacky
Suggested by: jhb
Sponsored by: Google Summer of Code 2007
PR: kern/77710
Approved by: re (kensmith)
3 arguments, but we had forgotten the second argument. Also make the
Linux statfs64 struct depend on the architecture because it has an
extra 4 bytes padding on amd64 compared to i386.
The three argument fix is from David Taylor, the struct statfs64
stuff is my fault. With this patch I can install i386 Linux matlab
on an amd64 machine.
Submitted by: David Taylor <davidt_at_yadt.co.uk>
Approved by: re (kensmith)
was used in assembler code in such a way that no unresolved relocation
records were generated, so ld didn't flag the problem. You can see
this with an 'nm' of the kernel. There will be 'U MAXCPU' on SMP systems.
The impact of this is that the intrcount/intrnames arrays do not have
the intended amount of space reserved. This could lead to interesting
problems due to the arrays being present in the middle of kernel code.
An overflow would be rather interesting as executable code would be used
as per-cpu incrementing interrupt counters.
This fixes it for now by exporting MAXCPU to the assembler. A better fix
might be to define these data structures in C - they're only referenced
in the kernel from C code these days anyway.
Approved by: re (kensmith)
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
previously the sched_lock. These bugs have existed for some time.
- Allow swapout to try each thread in a process individually and then
swapin the whole process if any of these fail. This allows us to move
most scheduler related swap flags into td_flags.
- Keep ki_sflag for backwards compat but change all in source tools to
use the new and more correct location of P_INMEM.
Reported by: pho
Reviewed by: attilio, kib
Approved by: re (kensmith)
of pages don't sum to anywhere near the total number of pages on amd64.
This is for the most part because uma_small_alloc() pages have never been
counted as wired pages, like their kmem_malloc() brethren. They should
be. This changes fixes that.
It is no longer necessary for the page queues lock to be held to free
pages allocated by uma_small_alloc(). I removed the acquisition and
release of the page queues lock from uma_small_free() on amd64 and ia64
weeks ago. This patch updates the other architectures that have
uma_small_alloc() and uma_small_free().
Approved by: re (kensmith)
per-primitive macros like MTX_NOPROFILE, SX_NOPROFILE or RW_NOPROFILE) is
not really honoured. In particular lock_profile_obtain_lock_failure() and
lock_profile_obtain_lock_success() are naked respect this flag.
The bug leads to locks marked with no-profiling to be profiled as well.
In the case of the clock_lock, used by the timer i8254 this leads to
unpredictable behaviour both on amd64 and ia32 (double faults panic,
sudden reboots, etc.). The amd64 clock_lock is also not marked as
not profilable as it should be.
Fix these bugs adding proper checks in the lock profiling code and at
clock_lock initialization time.
i8254 bug pointed out by: kris
Tested by: matteo, Giuseppe Cocomazzi <sbudella at libero dot it>
Approved by: jeff (mentor)
Approved by: re
topology foo functions.
Working at the patch for topology problems in ia32/amd64 evicted some
problems regarding functions ordering in the SI_SUB_CPU family of
SYSINIT'ed subsystems.
In order to avoid problems with new modified to involved functions, a
correct ordering is not semantically specified for SI_SUB_CPU functions
(for a larger view of the issue please visit:
http://lists.freebsd.org/pipermail/freebsd-current/2007-July/075409.html )
Discussed with: peter
Tested by: kris, Rui Paulo <rpaulo@FreeBSD.org>
Approved by: jeff
Approved by: re
with Linux 2.6 emulation. This shall be reimplemented once FreeBSD gets
native scheduler affinity syscalls.
Submitted by: rdivacky
Reviewed by: jkim
Sponsored by: Google Summer of Code 2007
Approved by: re (kensmith)
longer create a pv entry for that mapping. (The two exceptions are
mappings into the kernel's exec and pipe submaps.) Consequently, there is
no reason for get_pv_entry() to dig deep into the free page queues, i.e.,
use VM_ALLOC_SYSTEM, by default. This revision changes get_pv_entry() to
use VM_ALLOC_NORMAL by default, i.e., before calling pmap_collect() to
reclaim pv entries.
Approved by: re (kensmith)
and newer CPUs (including Core 2 and Core / Core 2 based Xeons). The
driver attaches to each cpu device and creates a sysctl node in that
device's sysctl context (dev.cpu.N.temperature). When invoked, the
handler binds to the appropriate CPU to ensure a correct reading.
Submitted by: Rui Paulo <rpaulo@fnop.net>
Sponsored by: Google Summer of Code 2007
Tested by: des, marcus, Constantine A. Murenin, Ian FREISLICH
Approved by: re (kensmith)
MFC after: 3 weeks
cpu_start_mp(). This is after we have read the cpuid registers to
calculate the hyperthreading_cpus value for the sysctl that enables or
disables hyperthread cores. Change mp_topology() to use that information
rather than trying to do it itself.
This solves the problem of ULE being incorrectly told that dual core
Athlon64 X2 or Operton cpus are hyperthreading cores. At the very least,
we now have a single piece of code to identify hyperthreading.
Obtained from: jhb
Approved by: re (kensmith)
value, then we would use a negative index into the trap_msg[] array
resulting in a nested page fault. Make the 'type' variable holding the
trap number unsigned to avoid this.
MFC after: 2 weeks
Approved by: re (rwatson)
print a one line error message. Add some comments on not being able to
trust the day of week field (I'll act on these comments in a follow up
commit).
Approved by: re
MFC after: 3 weeks
require fewer blocking loops.
- Don't use atomic ops with 4BSD or on UP.
- Only use the blocking loop if ULE is compiled in.
- Use the correct memory barrier.
Discussed with: attilio, jhb, ssouhlal
Tested by: current@
Approved by: re
kernels exposed by the recent fixes to resource limits for 32-bit processes
on 64-bit kernels:
- Let ABIs expose their maximum stack size via a new pointer in sysentvec
and use that in preference to maxssiz during exec() rather than always
using maxssiz for all processses.
- Apply the ABI's limit fixup to the previous stack size when adjusting
RLIMIT_STACK to determine if the existing mapping for the stack needs to
be grown or shrunk (as well as how much it should be grown or shrunk).
Approved by: re (kensmith)
the 7.0 timeframe.
This is needed because I4B is not locked and NET_NEEDS_GIANT goes away.
The plan is to lock I4B and bring everything back for 7.1.
Approved by: re (kensmith)
holding the page queues lock. Thus, the page table pages released by
pmap_remove() and pmap_remove_pages() can be freed after the page queues
lock is released.
Approved by: re (kensmith)
114 bytes of cmos ram in the PC clock chip. The big difference between
this and the Linux version is that we do not recalculate the checksums
for bytes 16..31.
We use this at work when cloning identical machines - we can copy the
bios settings as well. Reading /dev/nvram gives 114 bytes of data but
you can seek/read/write whichever bytes you like.
Yes, this is a "foot, gun, fire!" type of device.
more exposure. The current state of SCTP implementation is
considered to be ready for 32-bit platforms, but still need some
work/testing on 64-bit platforms.
Approved by: re (kensmith)
Discussed with: rrs
making the relevant files standard. This avoids duplication and
makes it easier to override/disable unwanted schemes. Since ARM
doesn't have a DEFAULTS configuration file, leave the source
files for the BSD and MBR partitioning schemes in files.arm for
now.
In particular:
- Add an explicative table for locking of struct vmmeter members
- Apply new rules for some of those members
- Remove some unuseful comments
Heavily reviewed by: alc, bde, jeff
Approved by: jeff (mentor)
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.
oldthread should point at before we return.
- When cpu_switch() is called the td_lock pointer in the old thread may
point at the blocked lock. This prevents other processors from
switching into this thread while we're still switching out. Wait
until we're done deactivating the vmspace before we release the
thread by assigning to td_lock.
- Before we can activate the new vmspace we must make sure that the new
thread is not assigned to the blocked lock. It may be in the process
of switching out on another cpu. Spin until the new thread is
available.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
- There is no globally visible scheduler lock any longer. For now the
watchdog can only check Giant. This model of checking particular locks
is flawed and should be revisited. Other metrics should be considered.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
- Use sched_throw() rather than replicating the same cpu_throw() code for
each architecture. This also allows the scheduler to use any locking it
may want to.
- Use the thread_lock() rather than sched_lock when preempting.
- The scheduler lock is not required to synchronize release_aps.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
given a specific value.
Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.
Reviewed by: alc, bde
Approved by: jeff (mentor)
sysctl_handle_int is not sizeof the int type you want to export.
The type must always be an int or an unsigned int.
Remove the instances where a sizeof(variable) is passed to stop
people accidently cut and pasting these examples.
In a few places this was sysctl_handle_int was being used on 64 bit
types, which would truncate the value to be exported. In these
cases use sysctl_handle_quad to export them and change the format
to Q so that sysctl(1) can still print them.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.
Requested by: alc
Approved by: jeff (mentor)
handler is wrapped in a couple of functions - a filter wrapper and an
ithread wrapper. In this case (and just in this case), the filter
wrapper could ask the system to schedule the ithread and mask the
interrupt source if the wrapped handler is composed of just an ithread
handler: modify the "old" interrupt code to make it support
this situation, while the "new" interrupt code is already ok.
Discussed with: jhb
used to return PAGE_SIZE without respect to restrictions of a DMA tag.
This affected all of the busdma load functions that use
_bus_dmamap_loader_buffer() as their back-end.
Reviewed by: scottl
Note on dcons:
To enable dcons in kernel, put the following lines in /boot/loader.conf.
You may also want to enable dcons in /etc/ttys.
boot_multicons="YES"
#Force dcons to be the high-level console if a firewire bus presents.
#hw.firewire.dcons_crom.force_console=1
FireWire/dcons support in loader will come shortly.
(i386/amd64 only)
debugger is quite capable of handling Giant-free execution at this
point. Several other similar comments remain in trap.c on both i386
and amd64 awaiting analysis.
Implement all futex atomic operations in assembler to not depend on the
fuword() that does not allow to distinguish between -1 and failure return.
Correctly return 0 from atomic operations on success.
In collaboration with: rdivacky
Tested by: Scot Hetzel <swhetzel gmail com>, Milos Vyletel <mvyletel mzm cz>
Sponsored by: Google SoC 2007
same way it was enabled for Linux binares in linuxulator.
This allows binaries built with -pie. Many ports auto-detect -fPIE support
in GCC 4.2 and build binaries FreeBSD was unable to run.
vmcnts. This can be used to abstract away pcpu details but also changes
to use atomics for all counters now. This means sched lock is no longer
responsible for protecting counts in the switch routines.
Contributed by: Attilio Rao <attilio@FreeBSD.org>
processes under 64-bit kernels). Previously, each 32-bit process overwrote
its resource limits at exec() time. The problem with this approach is that
the new limits affect all child processes of the 32-bit process, including
if the child process forks and execs a 64-bit process. To fix this, don't
ovewrite the resource limits during exec(). Instead, sv_fixlimits() is
now replaced with a different function sv_fixlimit() which asks the ABI to
sanitize a single resource limit. We then use this when querying and
setting resource limits. Thus, if a 32-bit process sets a limit, then
that new limit will be inherited by future children. However, if the
32-bit process doesn't change a limit, then a future 64-bit child will
see the "full" 64-bit limit rather than the 32-bit limit.
MFC is tentative since it will break the ABI of old linux.ko modules (no
other modules are affected).
MFC after: 1 week
passed zero as exit signal.
GCC 4.2 changes the kernel data segment layout not to have 0
in that memory location. This code ran by luck before and now
the luck has run out.
an APIC ID of 38 for its second CPU):
- Add a new MAX_APIC_ID constant for the highest valid APIC ID for modern
systems.
- Size the various arrays in the MADT, MP Table, and SMP code that are
indexed by APIC IDs to allow for up to MAX_APIC_ID.
- Explicitly go through and assign logical cpu ids to local APICs before
starting any of the APs up rather than doing it while starting up the
APs. This step is now where we honor MAXCPU.
MFC after: 1 week
- Split the intr_table_lock into an sx lock used for most things, and a
spin lock to protect intrcnt_index. Originally I had this as a spin lock
so interrupt code could use it to lookup sources. However, we don't
actually do that because it would add a lot of overhead to interrupts,
and if we ever do support removing interrupt sources, we can use other
means to safely do so w/o locking in the interrupt handling code.
- Replace is_enabled (boolean) with is_handlers (a count of handlers) to
determine if a source is enabled or not. This allows us to notice when
a source is no longer in use. When that happens, we now invoke a new
PIC method (pic_disable_intr()) to inform the PIC driver that the
source is no longer in use. The I/O APIC driver frees the APIC IDT
vector when this happens. The MSI driver no longer needs to have a
hack to clear is_enabled during msi_alloc() and msix_alloc() as a result
of this change as well.
- Add an apic_disable_vector() to reset an IDT vector back to Xrsvd to
complement apic_enable_vector() and use it in the I/O APIC and MSI code
when freeing an IDT vector.
- Add a new nexus hook: nexus_add_irq() to ask the nexus driver to add an
IRQ to its irq_rman. The MSI code uses this when it creates new
interrupt sources to let the nexus know about newly valid IRQs.
Previously the msi_alloc() and msix_alloc() passed some extra stuff
back to the nexus methods which then added the IRQs. This approach is
a bit cleaner.
- Change the MSI sx lock to a mutex. If we need to create new sources,
drop the lock, create the required number of sources, then get the lock
and try the allocation again.
o push much of the i386 and amd64 MD interrupt handling code
(intr_machdep.c::intr_execute_handlers()) into MI code
(kern_intr.c::ithread_loop())
o move filter handling to kern_intr.c::intr_filter_loop()
o factor out the code necessary to mask and ack an interrupt event
(intr_machdep.c::intr_eoi_src() and intr_machdep.c::intr_disab_eoi_src()),
and make them part of 'struct intr_event', passing them as arguments to
kern_intr.c::intr_event_create().
o spawn a private ithread per handler (struct intr_handler::ih_thread)
with filter and ithread functions.
Approved by: re (implicit?)
VM_PHYSSEG_SPARSE depending on whether the physical address space is
densely or sparsely populated with memory. The effect of this
definition is to determine which of two implementations of
vm_page_array and PHYS_TO_VM_PAGE() is used. The legacy
implementation is obtained by defining VM_PHYSSEG_DENSE, and a new
implementation that trades off time for space is obtained by defining
VM_PHYSSEG_SPARSE. For now, all architectures except for ia64 and
sparc64 define VM_PHYSSEG_DENSE. Defining VM_PHYSSEG_SPARSE on ia64
allows the entirety of my Itanium 2's memory to be used. Previously,
only the first 1 GB could be used. Defining VM_PHYSSEG_SPARSE on
sparc64 allows USIIIi-based systems to boot without crashing.
This change is a combination of Nathan Whitehorn's patch and my own
work in perforce.
Discussed with: kmacy, marius, Nathan Whitehorn
PR: 112194
- Simplify the amount of work that has be done for each architecture by
pushing more of the truly MI code down into the PCI bus driver.
- Don't bind MSI-X indicies to IRQs so that we can allow a driver to map
multiple MSI-X messages into a single IRQ when handling a message
shortage.
The changes include:
- Add a new pcib_if method: PCIB_MAP_MSI() which is called by the PCI bus
to calculate the address and data values for a given MSI/MSI-X IRQ.
The x86 nexus drivers map this into a call to a new 'msi_map()' function
in msi.c that does the mapping.
- Retire the pcib_if method PCIB_REMAP_MSIX() and remove the 'index'
parameter from PCIB_ALLOC_MSIX(). MD code no longer has any knowledge
of the MSI-X index for a given MSI-X IRQ.
- The PCI bus driver now stores more MSI-X state in a child's ivars.
Specifically, it now stores an array of IRQs (called "message vectors" in
the code) that have associated address and data values, and a small
virtual version of the MSI-X table that specifies the message vector
that a given MSI-X table entry uses. Sparse mappings are permitted in
the virtual table.
- The PCI bus driver now configures the MSI and MSI-X address/data
registers directly via custom bus_setup_intr() and bus_teardown_intr()
methods. pci_setup_intr() invokes PCIB_MAP_MSI() to determine the
address and data values for a given message as needed. The MD code
no longer has to call back down into the PCI bus code to set these
values from the nexus' bus_setup_intr() handler.
- The PCI bus code provides a callout (pci_remap_msi_irq()) that the MD
code can call to force the PCI bus to re-invoke PCIB_MAP_MSI() to get
new values of the address and data fields for a given IRQ. The x86
MSI code uses this when an MSI IRQ is moved to a different CPU, requiring
a new value of the 'address' field.
- The x86 MSI psuedo-driver loses a lot of code, and in fact the separate
MSI/MSI-X pseudo-PICs are collapsed down into a single MSI PIC driver
since the only remaining diff between the two is a substring in a
bootverbose printf.
- The PCI bus driver will now restore MSI-X state (including programming
entries in the MSI-X table) on device resume.
- The interface for pci_remap_msix() has changed. Instead of accepting
indices for the allocated vectors, it accepts a mini-virtual table
(with a new length parameter). This table is an array of u_ints, where
each value specifies which allocated message vector to use for the
corresponding MSI-X message. A vector of 0 forces a message to not
have an associated IRQ. The device may choose to only use some of the
IRQs assigned, in which case the unused IRQs must be at the "end" and
will be released back to the system. This allows a driver to use the
same remap table for different shortage values. For example, if a driver
wants 4 messages, it can use the same remap table (which only uses the
first two messages) for the cases when it only gets 2 or 3 messages and
in the latter case the PCI bus will release the 3rd IRQ back to the
system.
MFC after: 1 month
fault. The previous method zero'd out the page tables, invalidated the
TLB, and then entered a spin loop. The idea was that the instruction after
the TLB invalidate would result in a page fault and the page fault and
subsequent double fault wouldn't be able to determine the physical page
for their fault handlers' first instruction. This stopped working when
PGE (PG_G PTE/PDE bit) support was added as a TLB invalidate via %cr3
reload doesn't clear TLB entries with PG_G set. Thus, the CPU was still
able to map the virtual address for the spin loop and happily performed
its infinite loop.
The triple fault now uses a much more deterministic sledge-hammer approach
to generate a triple fault. First, the IDT descriptor is set to point to
an empty IDT, so any interrupts (including a double fault) will instantly
fault. Second, we trigger a int 3 breakpoint to force an interrupt and
kick off a triple fault.
MFC after: 3 days
vm.kmem_size_min. Useful when using ZFS to make sure that vm.kmem size will
be at least 256mb (for example) without forcing a particular value via vm.kmem_size.
Approved by: njl (mentor)
Reviewed by: alc
Dont "return" in linux_clone() after we forked the new process in a case
of problems. Move the copyout of p2->p_pid outside the emul_lock coverage.
Submitted by: Roman Divacky
code.
# There is some question about whether this code is even relevant any
# longer (it dates back to prehistoric times, i.e. present in r1.1),
# especially on amd64.
Reviewed by: jhb
cpufreq_pre_change is called before the change, giving each driver a chance
to revoke the change. cpufreq_post_change provides the results of the
change (success or failure). cpufreq_levels_changed gives the unit number
of the cpufreq device whose number of available levels has changed. Hook
in all the drivers I could find that needed it.
* TSC: update TSC frequency value. When the available levels change, take the
highest possible level and notify the timecounter set_cputicker() of that
freq. This gets rid of the "calcru: runtime went backwards" messages.
* identcpu: updates the sysctl hw.clockrate value
* Profiling: if profiling is active when the clock changes, let the user
know the results may be inaccurate.
Reviewed by: bde, phk
MFC after: 1 month
handles when activating a resource via bus_activate_resource() rather than
doing some of the work in bus_alloc_resource() and some of it in
bus_activate_resource().
One note is that when using isa_alloc_resourcev() on PC-98, drivers now
need to just use bus_release_resource() without explicitly calling
bus_deactivate_resource() first. nyan@ has already fixed all of the PC-98
drivers.
address ranges used by local and I/O APICs in the system. Some systems
also reserve these ranges as system resources via either PnPBIOS or
ACPI, so this device currently attaches after acpi0 and legacy0 so that
the system resources are given precedence.
addresses corresponding to system RAM. On amd64 ram0 uses the SMAP
and claims all the type 1 SMAP regions. On i386 ram0 uses the
dump_avail[] array. Note that on i386 we have to ignore regions above
4G in PAE kernels since bus resources use longs.
GETATTRs being generated - one from lookup()/namei() and the other
from nfs_open() (for cto consistency). This change eliminates the
GETATTR in nfs_open() if an otw GETATTR was done from the namei()
path. Instead of extending the vop interface, we timestamp each attr
load, and use this to detect whether a GETATTR was done from namei()
for this syscall. Introduces a thread-local variable that counts the
syscalls made by the thread and uses <pid, tid, thread syscalls> as
the attrload timestamp. Thanks to jhb@ and peter@ for a discussion on
thread state that could be used as the timestamp with minimal overhead.
For example, during a buildworld more than half of the calls do not
generate an IPI because the only TLB entry invalidated is on the calling
processor. This revision pushes down the acquisition and release of
smp_ipi_mtx into smp_tlb_shootdown() and smp_targeted_tlb_shootdown() and
instead uses sched_pin() and sched_unpin() in pmap_invalidate_*() so that
thread migration doesn't lead to a missed TLB invalidation.
Reviewed by: jhb
MFC after: 3 weeks
Linux does not check file descriptor when MAP_ANONYMOUS is set.
This should fix recent LTP test regressions.
Reported by: Scot Hetzel (swhetzel at gmail dot com)
netchild
Rounding addr upwards to next 2M boundary in pmap_growkernel() could
cause addr to become 0, resulting in an early return without populating
the last PDE.
Reported and tested by: kris
Suggested by: alc
MFC after: 1 week
- PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC.
Linux/ia64's i386 emulation layer does this and it complies with Linux
header files. This fixes mmap05 LTP test case on amd64.
- Do not adjust stack size when failure has occurred.
- Synchronize i386 mmap/mprotect with amd64.
partitioning class that supports multiple schemes. Current
schemes supported are APM (Apple Partition Map) and GPT.
Change all GEOM_APPLE anf GEOM_GPT options into GEOM_PART_APM
and GEOM_PART_GPT (resp).
The ctlreq interface supports verbs to create and destroy
partitioning schemes on a disk; to add, delete and modify
partitions; and to commit or undo changes made.
variable to avoid invalid constraints in dead code. Use an array of
u_char's (inside a struct) instead of a char/short/int/long variable so
that the variable and its accesses can be spelled in the same way in all
cases and code doesn't need to be cloned just to hold the spelling
differences.
Fixed strict-aliasing errors in PCPU_SET() and in the amd64 PCPU_GET().
Cast to (void *) as in rev.1.37 of the i386 version where the errors
were fixed for the i386 PCPU_GET() only. It would be more correct to
copy to and from the temp. variable using memcpy(), but then an
ifdef tangle would be required to ensure using the builtin memcpy().
We depend on fairly aggressive optimization to put the temp. variable
only in a register despite it being copied using
*(type *)(void *)&anothertype and could depend on this when using
memcpy() too. This seems to work right even for -O0, but the -O0 case
has not been completely tested.
This change gives identical object code for all object files in LINT
on amd64 (except for one file with a __TIME__ stamp). For LINT on
i386 it gives unimportant differences in instruction order and padding
in a few object files. This was only tested for -O.
This change (actually a previous version of it) gives the following
reductions in the number of object files in LINT that fail to compile
with -O2 but without the -fno-strict-aliasing kludge:
- amd64: 29 (down from 211)
- i386: 36 (down from 47)
gcc-3.4.6 actually allows the invalid constraints that result from not
using the temp. variable, at least with -O[1-2], but gcc-3.3.3 crashes
on them and I don't want to depend on compiler bugs.
register takes 16 characters (64-bit register in hex). In practice this
is a slight bit of overkill as 7 of the 56 registers are only 32-bit, but
having the buffer too small results in remote kgdb trashing kernel memory
when it connects.
PR: amd64/108673
Submitted by: Ravi Murty, Nikhil Rao @ Intel
MFC after: 3 days
the space allocated for the double fault handler since this space
is otherwise unused till the time a double fault occurs.
This change should have been committed alongside r1.127 of
"exception.S", but I somehow missed doing so.
Problem reported by: jeff
Pointy hat to: jkoshy
setrunqueue() was mostly empty. The few asserts and thread state
setting were moved to the individual schedulers. sched_add() was
chosen to displace it for naming consistency reasons.
- Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
different on all three schedulers where it was only called in one place
each.
- Remove the long ifdef'd out remrunqueue code.
- Remove the now redundant ts_state. Inspect the thread state directly.
- Don't set TSF_* flags from kern_switch.c, we were only doing this to
support a feature in one scheduler.
- Change sched_choose() to return a thread rather than a td_sched. Also,
rely on the schedulers to return the idlethread. This simplifies the
logic in choosethread(). Aside from the run queue links kern_switch.c
mostly does not care about the contents of td_sched.
Discussed with: julian
- Move the idle thread loop into the per scheduler area. ULE wants to
do something different from the other schedulers.
Suggested by: jhb
Tested on: x86/amd64 sched_{4BSD, ULE, CORE}.
used by clock code, so don't export it to the world for machdep.c to
initialize. There is a minor problem initializing it before it is
used, since although clock initialization is split up so that parts
of it can be done early, the first part was never done early enough
to actually work. Split it up a bit more and do the first part as
late as possible to document the necessary order. The functions that
implement the split are still bogusly exported.
Cleaned up initialization of the i8254 clock hardware using the new
split. Actually initialize it early enough, and don't work around it
not being initialized in DELAY() when DELAY() is called early for
initialization of some console drivers.
This unfortunately moves a little more code before the early debugger
breakpoint so that it is harder to debug. The ordering of console and
related initialization is delicate because we want to do as little as
possible before the breakpoint, but must initialize a console.
- First off, device drivers really do need to know if they are allocating
MSI or MSI-X messages. MSI requires allocating powerof2() messages for
example where MSI-X does not. To address this, split out the MSI-X
support from pci_msi_count() and pci_alloc_msi() into new driver-visible
functions pci_msix_count() and pci_alloc_msix(). As a result,
pci_msi_count() now just returns a count of the max supported MSI
messages for the device, and pci_alloc_msi() only tries to allocate MSI
messages. To get a count of the max supported MSI-X messages, use
pci_msix_count(). To allocate MSI-X messages, use pci_alloc_msix().
pci_release_msi() still handles both MSI and MSI-X messages, however.
As a result of this change, drivers using the existing API will only
use MSI messages and will no longer try to use MSI-X messages.
- Because MSI-X allows for each message to have its own data and address
values (and thus does not require all of the messages to have their
MD vectors allocated as a group), some devices allow for "sparse" use
of MSI-X message slots. For example, if a device supports 8 messages
but the OS is only able to allocate 2 messages, the device may make the
best use of 2 IRQs if it enables the messages at slots 1 and 4 rather
than default of using the first N slots (or indicies) at 1 and 2. To
support this, add a new pci_remap_msix() function that a driver may call
after a successful pci_alloc_msix() (but before allocating any of the
SYS_RES_IRQ resources) to allow the allocated IRQ resources to be
assigned to different message indices. For example, from the earlier
example, after pci_alloc_msix() returned a value of 2, the driver would
call pci_remap_msix() passing in array of integers { 1, 4 } as the
new message indices to use. The rid's for the SYS_RES_IRQ resources
will always match the message indices. Thus, after the call to
pci_remap_msix() the driver would be able to access the first message
in slot 1 at SYS_RES_IRQ rid 1, and the second message at slot 4 at
SYS_RES_IRQ rid 4. Note that the message slots/indices are 1-based
rather than 0-based so that they will always correspond to the rid
values (SYS_RES_IRQ rid 0 is reserved for the legacy INTx interrupt).
To support this API, a new PCIB_REMAP_MSIX() method was added to the
pcib interface to change the message index for a single IRQ.
Tested by: scottl
Dont expose em->shared to the outside world before its properly
initialized. Might not affect anything but its at least a better
coding style.
Dont expose em via p->p_emuldata until its properly initialized.
This also enables us to get rid of some locking and simplify the
code because we are workin on a local copy.
In linux_fork and linux_vfork create the process in stopped state
to be sure that the new process runs with fully initialized emuldata
structure [1]. Also fix the vfork (both in linux_clone and linux_vfork)
race that could result in never woken up process [2].
Reported by: Scot Hetzel [1]
Suggested by: jhb [2]
Reviewed by: jhb (at least some important parts)
Submitted by: rdivacky
Tested by: Scot Hetzel (on amd64)
Change 2 comments (in the new code) to comply to style(9).
Suggested by: jhb
KERNBASE for the first 1 MB of RAM instead of calling pmap_mapdev().
pmap_mapdev() knows how to handle the first 1 MB (and has known for a
while now) and properly maps the memory as UC to boot.
MFC after: 2 weeks
we actually issue preemptions.
- Remove the #ifdef IPI_PREEMPTION so it is always compiled in. Leave
the option which optionally enables support in sched_4bsd. sched_ule.c
will soon use this functionality as a run time rather than compile time
option.
- Compare against the idlethread rather than the priority. There are some
idle prio tasks that we can preempt.
Discussed with: ups
Tested on: i386, amd64
Bring the linux mmap code more into line with how linux (2.4.x) behaves.
Tested by: Scot Hetzel <swhetzel@gmail.com> on amd64 without PROT_EXEC
Additionally to the i386 version always use PROT_EXEC in the mapping like the
previous version of the amd64 code did. We need to examinate this further to
decide what the right thing to do is. For now this fixes several problems in
the LTP test runs and should behave regarding PROT_EXEC like before.
