Clearing a page table entry's accessed bit and setting the page's
PG_REFERENCED flag in pmap_protect() can't really be justified, so
don't do it. Moreover, on ia64, don't set the page's dirty field
unless pmap_protect() is removing write access.
In the end, it does help fixing /dev/io usage from multithreaded
processes.
- On i386 and amd64 the old behaviour is kept but multithreaded
processes must use the new interface in order to work well.
- Support for the other architectures is greatly improved, where
necessary, by the necessity to define very small things now.
Manpage update will happen shortly.
Sponsored by: Sandvine Incorporated
PR: threads/116181
Reviewed by: emaste, marcel
MFC after: 3 weeks
pmap_ts_referenced() is not always appropriate for checking whether or
not pages have been referenced because it clears any reference bits
that it encounters. For example, in mincore(), clearing the reference
bits has two negative consequences. First, it throws off the activity
count calculations performed by the page daemon. Specifically, a page
on which mincore() has called pmap_ts_referenced() looks less active
to the page daemon than it should. Consequently, the page could be
deactivated prematurely by the page daemon. Arguably, this problem
could be fixed by having mincore() duplicate the activity count
calculation on the page. However, there is a second problem for which
that is not a solution. In order to clear a reference on a 4KB page,
it may be necessary to demote a 2/4MB page mapping. Thus, a mincore()
by one process can have the side effect of demoting a superpage
mapping within another process!
bus number 1 in domain 1 has the devices we're looking for.
For the busses that are present, the SAL call returns an
non-NULL value for the addr parameter so use that as well
as the status code to determine whether to create a child.
Save the domain, bus number and PROM address in the softc
after assigning the driver to the new device.
This yields:
...
pcib0: <SGI PCI-X host controller> on motherboard
pci0: <PCI bus> on pcib0
pci0: domain=1, physical bus=1
...
pcib1: <SGI PCI-X host controller> on motherboard
pci1: <PCI bus> on pcib1
pci1: domain=2, physical bus=1
...
The sequence number is used as the name of a sysctl node,
under which we add the MCA records using the CPU id as the
leaf name.
Add the hw.mca.inject sysctl to provide a way to inject
MC errors and trigger machine checks.
PR: ia64/113102
o Switch to ITANIUM2 has the cpu. This has absolutely no effect
on the code, but makes for a better example.
o Drop COMPAT_FREEBSD6. We're tier 2, so you're supposed to run
8-stable or newer.
o Add PREEMPTION. It works now.
o Remove HWPMC_HOOKS. We don't have support for hwpmc yet.
o Add a bunch of new devices: atapist, hptiop, amr, ips, twa, igb,
ixgbe, ae, age, alc, ale, bce, bfe, et, jme, msk, nge, sk, ste,
stge, tx, vge, axe, rue, udav, fwip, and all USB serial.
o Remove "legacy" devices: le, vx, dc, pcn, rl, sis.
Make sure to the module list is a superset of what goes into GENERIC.
with PCI busses. Remove nexus_read_ivar() and nexus_write_ivar()
to give default behaviour. Remove <machine/nexusvar.h> as well,
because there's nothing in it that's being used.
to ia64_enable_intr(). This reduces confusion with intr_disable() and
intr_restore().
Have configure_final() call ia64_finalize_intr() instead of enable_intr()
in preparation of adding support for binding interrupts to all CPUs.
have the BSP use IPIs to trigger clock interrupts on the APs.
This allows us to run on hardware configurations for which the
ITC has non-uniform frequencies across CPUs.
While here, change the clock XIV to type IPI so as to protect
the interrupt delivery against CPU re-balancing once that's
implemented.
to the image_params struct instead of several members of that struct
individually. This makes it easier to expand its arguments in the future
without touching all platforms.
Reviewed by: jhb
other than in a potentially dangerous KASSERT.
o Hand-inline pmap_remove_page() as it's only called from 1 place and
the abstraction that pmap_remove_page() provides is not enough to
warrant the obfuscation. Eliminate the dangerous KASSERT in the
process.
o In pmap_remove_pte(), remove the KASSERT for pmap being the current
one as it's not safe in the face of CPU migration.
than in a KASSERT. The KASSERT is broken in that it's done outside the
critical section and as such isn't protected against CPU migration.
Improve pmap_invalidate_page() as follows:
o calculate vhpt_ofs inside the critical region for exactly the same
reason.
o calculate the tag outside the FOREACH loop, as it's loop-invariant.
This is more efficient.
o Replace the test and set with an atomic cmpset operation because we
are changing other CPU's VHPT tables and this avoids invalidating
after the entry got modified. Not necessarily a problem, but better
safe than sorry.
before we grab the mutex. Don't assert that they must be disabled at
that point. We pretty much bypass all logic in that case anyway and
leave immediately, so there's no harm.
preemption doesn't happen until after all pending interrupt have
been services.
While here again, simplify the EOI handling by doing it after we
call the XIV-specific handlers, rather than in each of them. The
original thought was that we may want to do an EOI first and the
actual IPI handling next, but that's mostly a micro-optimization.
cycles. This serves 2 purposes:
1. It prevents preemption and CPU migration while running SAL code.
2. It reduces the chance of stack overflows: we're supposed to enter
SAL with at least 16KB of either memory- or register stack space,
which we can't do without switching to a different stack.
This is not for multiple inclusion purposes, because _regset.h already
handles this, but to enable inclusion of the MD header by cross-tools
on non-ia64 installations. The cross-tool can include _regset.h itself
before including MD headers that depend on it.
o Introduce XIV, eXternal Interrupt Vector, to differentiate from
the interrupts vectors that are offsets in the IVT (Interrupt
Vector Table). There's a vector for external interrupts, which
are based on the XIVs.
o Keep track of allocated and reserved XIVs so that we can assign
XIVs without hardcoding anything. When XIVs are allocated, an
interrupt handler and a class is specified for the XIV. Classes
are:
1. architecture-defined: XIV 15 is returned when no external
interrupt are pending,
2. platform-defined: SAL reports which XIV is used to wakeup
an AP (typically 0xFF, but it's 0x12 for the Altix 350).
3. inter-processor interrupts: allocated for SMP support and
non-redirectable.
4. device interrupts (i.e. IRQs): allocated when devices are
discovered and are redirectable.
o Rewrite the central interrupt handler to call the per-XIV
interrupt handler and rename it to ia64_handle_intr(). Move
the per-XIV handler implementation to the file where we have
the XIV allocation/reservation. Clock interrupt handling is
moved to clock.c. IPI handling is moved to mp_machdep.c.
o Drop support for the Intel 8259A because it was broken. When
XIV 0 is received, the CPU should initiate an INTA cycle to
obtain the interrupt vector of the 8259-based interrupt. In
these cases the interrupt controller we should be talking to
WRT to masking on signalling EOI is the 8259 and not the I/O
SAPIC. This requires adriver for the Intel 8259A which isn't
available for ia64. Thus stop pretending to support ExtINTs
and instead panic() so that if we come across hardware that
has an Intel 8259A, so have something real to work with.
o With XIVs for IPIs dynamically allocatedi and also based on
priority, define the IPI_* symbols as variables rather than
constants. The variable holds the XIV allocated for the IPI.
o IPI_STOP_HARD delivers a NMI if possible. Otherwise the XIV
assigned to IPI_STOP is delivered.
a long time and has gone unnoticed just as long, because I kept
using sched_4bsd (due to sched_ule not working with preemption),
but GENERIC had sched_ule by default -- including SMP.
While here, remove unused inclusion of <machine/clock.h>, remove
totally bogus inclusion of <i386/include/specialreg.h>.
COMPAT_43TTY enables the sgtty interface. Even though its exposure has
only been removed in FreeBSD 8.0, it wasn't used by anything in the base
system in FreeBSD 5.x (possibly even 4.x?). On those releases, if your
ports/packages are less than two years old, they will prefer termios
over sgtty.
for upcoming 64-bit PowerPC and MIPS support. This renames the COMPAT_IA32
option to COMPAT_FREEBSD32, removes some IA32-specific code from MI parts
of the kernel and enhances the freebsd32 compatibility code to support
big-endian platforms.
Reviewed by: kib, jhb
o Assign vectors based on priority, because vectors have
implied priority in hardware.
o Use unordered memory accesses to the I/O sapic and use
the acceptance form of the mf instruction.
o Remove the sapicreg.h and sapicvar.h headers. All definitions
in sapicreg.h are private to sapic.c and all definitions in
sapicvar.h are either private or interface functions. Move the
interface functions to intr.h.
o Hide the definition of struct sapic.
o Eliminate IA64_PHYS_TO_RR6 and change all places where the macro is used
by calling either bus_space_map() or pmap_mapdev().
o Implement bus_space_map() in terms of pmap_mapdev() and implement
bus_space_unmap() in terms of pmap_unmapdev().
o Have ia64_pib hold the uncached virtual address of the processor interrupt
block throughout the kernel's life and access the elements of the PIB
through this structure pointer.
This is a non-functional change with the exception of using ia64_ld1() and
ia64_st8() to write to the PIB. We were still using assignments, for which
the compiler generates semaphore reads -- which cause undefined behaviour
for uncacheable memory. Note also that the memory barriers in ipi_send() are
critical for proper functioning.
With all the mapping of uncached memory done by pmap_mapdev(), we can keep
track of the translations and wire them in the CPU. This then eliminates
the need to reserve a whole region for uncached I/O and it eliminates
translation traps for device I/O accesses.
the 'debugging' section of any HEAD kernel and enable for the mainstream
ones, excluding the embedded architectures.
It may, of course, enabled on a case-by-case basis.
Sponsored by: Sandvine Incorporated
Requested by: emaste
Discussed with: kib
path. When the taken branch leaves the kernel and enters the process,
we still need to execute the instruction at that address. Don't raise
SIGTRAP when we branch into the process, but enable single-stepping
instead.
I/O port access is implemented on Itanium by reading and writing to a
special region in memory. To hide details and avoid misaligned memory
accesses, a process did I/O port reads and writes by making a MD system
call. There's one fatal problem with this approach: unprivileged access
was not being prevented. /dev/io serves that purpose on amd64/i386, so
employ it on ia64 as well. Use an ioctl for doing the actual I/O and
remove the sysarch(2) interface.
Backward compatibility is not being considered. The sysarch(2) approach
was added to support X11, but support for FreeBSD/ia64 was never fully
implemented in X11. Thus, nothing gets broken that didn't need more work
to begin with.
MFC after: 1 week
sys/conf/makeLINT.mk to only do certain things for certain
architectures.
Note that neither arm nor mips have the Makefile there, thus
essentially not (yet) supporting LINT. This would enable them
do add special treatment to sys/conf/makeLINT.mk as well chosing
one of the many configurations as LINT.
This is a hack of doing this and keeping it in a separate commit
will allow us to more easily identify and back it out.
Discussed on/with: arch, jhb (as part of the LINT-VIMAGE thread)
MFC after: 1 month
o Optimize for memory mapped I/O by making all I/O port acceses function
calls and marking the test for the IA64_BUS_SPACE_IO tag with
__predict_false(). Implement the I/O port access functions in a new
file, called bus_machdep.c.
o Change the bus_space_handle_t for memory mapped I/O to the virtual
address rather than the physical address. This eliminates the PA->VA
translation for every I/O access. The handle for I/O port access is
still the port number.
o Move inb(), outb(), inw(), outw(), inl(), outl(), and their string
variants from cpufunc.h and define them in bus.h. On ia64 these are
not CPU functions at all. In bus.h they are merely aliases for the
new I/O port access functions defined in bus_machdep.h.
o Handle the ACPI resource bug in nexus_set_resource(). There we can
do it once so that we don't have to worry about it whenever we need
to write to an I/O port that is really a memory mapped address.
The upshot of this change is that the KBI is better defined and that I/O
port access always involves a function call, allowing us to change the
actual implementation without breaking the KBI. For memory mapped I/O the
virtual address is abstracted, so that we can change the VA->PA mapping
in the kernel without causing an KBI breakage. The exception at this time
is for bus_space_map() and bus_space_unmap().
MFC after: 1 week.
This replaces d_mmap() with the d_mmap2() implementation and also
changes the type of offset to vm_ooffset_t.
Purge d_mmap2().
All driver modules will need to be rebuilt since D_VERSION is also
bumped.
Reviewed by: jhb@
MFC after: Not in this lifetime...
Fix some wrong usages.
Note: this does not affect generated binaries as this argument is not used.
PR: 137213
Submitted by: Eygene Ryabinkin (initial version)
MFC after: 1 month
The frequencies are in MHz (i.e. a value of 1000 represents 1GHz). The
frequencies are rounded to the nearest whole MHz.
While here, rename and re-type bus_frequency, processor_frequency and
itc_frequency to bus_freq, cpu_freq and itc_freq and make them static.
As unsigned integers, the hw.freq.cpu sysctl can more easily be made
generic (across all architectures) making porting easier.
MFC after: 3 days
excluded, as it's used by MI code) and mode the sysctl variables from
pcpu_stats to pcpu_md.
Adjust all references accordingly.
While nearby, change the PCPU sysctl tree so that they match the CPU
device sysctl tree -- they are now children of a static node called
"machdep.cpu" and are named only with their cpu ID.
allocating MAXCPU VHPTs up-front. This allows us to max-out MAXCPU
without memory waste -- MAXCPU is now 32 for SMP kernels.
This change also eliminates the VHPT scaling based in the total
memory in the system. It's the workload that determines the best size
of the VHPT. The workload can be affected by the amount of memory,
but not necessarily. For example, there's no performance difference
between VHPT sizes of 256KB, 512KB and 1MB when building the LINT
kernel. This was observed with a system that has 8GB of memory.
By default the kernel will allocate a 1MB VHPT. The user can tune the
system with the "machdep.vhpt.log2size" tunable.
Memory accesses are posted in program order by virtue of the
uncacheable memory attribute.
Since GCC, by default, adds acquire and release semantics to
volatile memory loads and stores, we need to use inline assembly
to guarantee it. With inline assembly, we don't need volatile
pointers anymore.
Itanium does not support semaphore instructions to uncacheable
memory.
adding statistics counters to the PCPU structure. Export the counters
through sysctl by giving each PCPU structure its own sysctl context.
While here, fix cnt.v_intr by not just having it count clock interrupts,
but every interrupt and add more counters for each interrupt source.
the kernel stack at all. The new USB stack simply caused a change
in timing that triggered a firmware bug more often. The addition
of PRINTF_BUFR_SIZE apparently triggered the same firmware bug
even more reliably.
But even with KSTACK_PAGES=5, one instance of the firmware bug
remained: booting with a CD inserted. This problem was run into
by accident after installing Debian and having to boot FreeBSD
to fixup the GPT partitioning (Thanks... not). After bumping
KSTACK_PAGES to 5, it was pretty unbelievable that the stack was
still being too small.
After updating the firmware we could boot with a CD inserted and
KSTACK_PAGES could be lowered back to 4 pages without problems.
Note: It is believed to be a timing related firmware bug, because
the machine check information showed access to the serial console
on one CPU and access to the EHCI HCD on the other CPU. Since
both are devices on the management unit and thus virtualized in
some way, any execution trace that does not include concurrent
access to the BMC from both CPUs is fine.
Note also that it's not understood exactly how increasing the
kernel stack avoided hitting the firmware bug. A change in page
faults does change timing, but it's not known if that's what's
happening here.
In any case: the problem is being monitored. Reverting back to
4 pages for the kernel stack is preferred, because it makes it
easier to switch to 16K pages (double the page size) without
wasting too much memory by not being able to half the number of
pages...
to panic when we have an unexpected TLB fault while interrupt
collection is disabled. Use a token rather than the actual address
of the restart point to avoid the need for the movl instruction.
The token is arbitrary. For the drummers: it's based on a single
paradiddle.
o Move all code into a single file for easier maintenance.
o Use a single global lock to avoid having to handle either
multiple locks or race conditions.
o Make sure to disable the high FP registers after saving
or dropping them.
o use msleep() to wait for the other CPU to save the high
FP registers.
This change fixes the high FP inconsistency panics.
A single global lock typically serializes too much, which may
be noticable when a lot of threads use the high FP registers,
but in that case it's probably better to switch the high FP
context synchronuously. Put differently: cpu_switch() should
switch the high FP registers if the incoming and outgoing
threads both use the high FP registers.
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.
Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
more stack hungry as compared to the old one that my RX2660 gets
a machine check and spontaneously reboots at the time the USB DVD
drive is found and attached to CAM as a mass storage device. This
doesn't happen always, but definitely varies per kernel build.
Likewise when using a 128-byte printf buffer. The additional 128
bytes that printf needs seems to be enough to have the memory stack
and register stack collide and causing a machine check.
Thus: Bump KSTACK_PAGES from 4 to 5.
the memory or D-cache, depending on the semantics of the platform.
vm_sync_icache() is basically a wrapper around pmap_sync_icache(),
that translates the vm_map_t argumument to pmap_t.
o Introduce pmap_sync_icache() to all PMAP implementation. For powerpc
it replaces the pmap_page_executable() function, added to solve
the I-cache problem in uiomove_fromphys().
o In proc_rwmem() call vm_sync_icache() when writing to a page that
has execute permissions. This assures that when breakpoints are
written, the I-cache will be coherent and the process will actually
hit the breakpoint.
o This also fixes the Book-E PMAP implementation that was missing
necessary locking while trying to deal with the I-cache coherency
in pmap_enter() (read: mmu_booke_enter_locked).
The key property of this change is that the I-cache is made coherent
*after* writes have been done. Doing it in the PMAP layer when adding
or changing a mapping means that the I-cache is made coherent *before*
any writes happen. The difference is key when the I-cache prefetches.
by looking at the bases used for non-relocatable executables by gnu ld(1),
and adjusting it slightly.
Discussed with: bz
Reviewed by: kan
Tested by: bz (i386, amd64), bsam (linux)
MFC after: some time
first and the native ia32 compat as middle (before other things).
o(ld)brandinfo as well as third party like linux, kfreebsd, etc.
stays on SI_ORDER_ANY coming last.
The reason for this is only to make sure that even in case we would
overflow the MAX_BRANDS sized array, the native FreeBSD brandinfo
would still be there and the system would be operational.
Reviewed by: kib
MFC after: 1 month
has proven to have a good effect when entering KDB by using a NMI,
but it completely violates all the good rules about interrupts
disabled while holding a spinlock in other occasions. This can be the
cause of deadlocks on events where a normal IPI_STOP is expected.
* Adds an new IPI called IPI_STOP_HARD on all the supported architectures.
This IPI is responsible for sending a stop message among CPUs using a
privileged channel when disponible. In other cases it just does match a
normal IPI_STOP.
Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64
architectures, while on the other has a normal IPI_STOP effect. It is
responsibility of maintainers to eventually implement an hard stop
when necessary and possible.
* Use the new IPI facility in order to implement a new userend SMP kernel
function called stop_cpus_hard(). That is specular to stop_cpu() but
it does use the privileged channel for the stopping facility.
* Let KDB use the newly introduced function stop_cpus_hard() and leave
stop_cpus() for all the other cases
* Disable interrupts on CPU0 when starting the process of APs suspension.
* Style cleanup and comments adding
This patch should fix the reboot/shutdown deadlocks many users are
constantly reporting on mailing lists.
Please don't forget to update your config file with the STOP_NMI
option removal
Reviewed by: jhb
Tested by: pho, bz, rink
Approved by: re (kib)
a device pager (OBJT_DEVICE) object in that it uses fictitious pages to
provide aliases to other memory addresses. The primary difference is that
it uses an sglist(9) to determine the physical addresses for a given offset
into the object instead of invoking the d_mmap() method in a device driver.
Reviewed by: alc
Approved by: re (kensmith)
MFC after: 2 weeks
dependent memory attributes:
Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the
fact that there are machine-dependent memory attributes that have
nothing to do with controlling the cache's behavior.
Introduce vm_object_set_memattr() for setting the default memory
attributes that will be given to an object's pages.
Introduce and use pmap_page_{get,set}_memattr() for getting and
setting a page's machine-dependent memory attributes. Add full
support for these functions on amd64 and i386 and stubs for them on
the other architectures. The function pmap_page_set_memattr() is also
responsible for any other machine-dependent aspects of changing a
page's memory attributes, such as flushing the cache or updating the
direct map. The uses include kmem_alloc_contig(), vm_page_alloc(),
and the device pager:
kmem_alloc_contig() can now be used to allocate kernel memory with
non-default memory attributes on amd64 and i386.
vm_page_alloc() and the device pager will set the memory attributes
for the real or fictitious page according to the object's default
memory attributes.
Update the various pmap functions on amd64 and i386 that map pages to
incorporate each page's memory attributes in the mapping.
Notes: (1) Inherent to this design are safety features that prevent
the specification of inconsistent memory attributes by different
mappings on amd64 and i386. In addition, the device pager provides a
warning when a device driver creates a fictitious page with memory
attributes that are inconsistent with the real page that the
fictitious page is an alias for. (2) Storing the machine-dependent
memory attributes for amd64 and i386 as a dedicated "int" in "struct
md_page" represents a compromise between space efficiency and the ease
of MFCing these changes to RELENG_7.
In collaboration with: jhb
Approved by: re (kib)
called to prefault pages. This is an obvious place for making
sure the I-cache is coherent. It was missing though. As such,
execution over NFS and ZFS file systems was failing. NFS was
fixed the wrong way (by flushing the D-cache as part of the
NFS code) in a previous commit. ZFS problems were encountered
after that and indicated that something else was wrong...
Approved by: re (kib)
o add to platforms where it was missing (arm, i386, powerpc, sparc64, sun4v)
o define as "1" on amd64 and i386 where there is no restriction
o make the type returned consistent with ALIGN
o remove _ALIGNED_POINTER
o make associated comments consistent
Reviewed by: bde, imp, marcel
Approved by: re (kensmith)
More applications (including Firefox) seem to depend on this nowadays,
so not having this enabled by default is a bad idea.
Proposed by: miwi
Patch by: Florian Smeets <flo kasimir com>
Approved by: re (kib)
required by video card drivers. Specifically, this change introduces
vm_cache_mode_t with an appropriate VM_CACHE_DEFAULT definition on all
architectures. In addition, this changes adds a vm_cache_mode_t parameter
to kmem_alloc_contig() and vm_phys_alloc_contig(). These will be the
interfaces for allocating mapped kernel memory and physical memory,
respectively, with non-default cache modes.
In collaboration with: jhb
- Modules and kernel code alike may use DPCPU_DEFINE(),
DPCPU_GET(), DPCPU_SET(), etc. akin to the statically defined
PCPU_*. Requires only one extra instruction more than PCPU_* and is
virtually the same as __thread for builtin and much faster for shared
objects. DPCPU variables can be initialized when defined.
- Modules are supported by relocating the module's per-cpu linker set
over space reserved in the kernel. Modules may fail to load if there
is insufficient space available.
- Track space available for modules with a one-off extent allocator.
Free may block for memory to allocate space for an extent.
Reviewed by: jhb, rwatson, kan, sam, grehan, marius, marcel, stas
not in cpu_exit(). The latter is called after td_md.md_highfp_mtx
has been destroyed, which results in a race condition when another
thread wants to use the high FP registers on the CPU that still has
the high FP registers in question.
goal of shipping 8.0 with MAC support in the default kernel. No policies
will be compiled in or enabled by default, but it will now be possible to
load them at boot or runtime without a kernel recompile.
While the framework is not believed to impose measurable overhead when no
policies are loaded (a result of optimization over the past few months in
HEAD), we'll continue to benchmark and optimize as the release approaches.
Please keep an eye out for performance or functionality regressions that
could be a result of this change.
Approved by: re (kensmith)
Obtained from: TrustedBSD Project
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex. Jails may
have their own host information, or they may inherit it from the
parent/system. The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL. The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.
The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.
Approved by: bz (mentor)
I don't want people to override the mutex when allocating a TTY. It has
to be there, to keep drivers like syscons happy. So I'm creating a
tty_alloc_mutex() which can be used in those cases. tty_alloc_mutex()
should eventually be removed.
The advantage of this approach, is that we can just remove a function,
without breaking the regular API in the future.
Once AP's are launched, their MCA state information is stored and later obtainable using a sysctl. Since the size of the MCA state information is unknown, it will be malloc'ed as needed. However, when 'ia64_ap_startup' runs, it's not yet safe to call malloc and this may cause 'panic: blockable sleep lock (sleep mutex) 8192 @ /usr/src/sys/vm/uma_core.c'. This commit avoids this issue by scheduling a separate kthread to obtain this information, which immediately terminates afterwards.
possible future I-cache coherency operation can succeed. On ARM
for example the L1 cache can be (is) virtually mapped, which
means that any I/O that uses temporary mappings will not see the
I-cache made coherent. On ia64 a similar behaviour has been
observed. By flushing the D-cache, execution of binaries backed
by md(4) and/or NFS work reliably.
For Book-E (powerpc), execution over NFS exhibits SIGILL once in
a while as well, though cpu_flush_dcache() hasn't been implemented
yet.
Doing an explicit D-cache flush as part of the non-DMA based I/O
read operation eliminates the need to do it as part of the
I-cache coherency operation itself and as such avoids pessimizing
the DMA-based I/O read operations for which D-cache are already
flushed/invalidated. It also allows future optimizations whereby
the bcopy() followed by the D-cache flush can be integrated in a
single operation, which could be implemented using on-chips DMA
engines, by-passing the D-cache altogether.
a fair number of static data structures, making this an unlikely
option to try to change without also changing source code. [1]
Change default cache line size on ia64, sparc64, and sun4v to 128
bytes, as this was what rtld-elf was already using on those
platforms. [2]
Suggested by: bde [1], jhb [2]
MFC after: 2 weeks
CACHE_LINE_SIZE constant. These constants are intended to
over-estimate the cache line size, and be used at compile-time
when a run-time tuning alternative isn't appropriate or
available.
Defaults for all architectures are 64 bytes, except powerpc
where it is 128 bytes (used on G5 systems).
MFC after: 2 weeks
Discussed on: arch@
a tag that has BUS_DMA_KEEP_PG_OFFSET set. Otherwise the page could be
reused with a non-zero offset by a tag that doesn't have
BUS_DMA_KEEP_PG_OFFSET leading to data corruption.
Sleuthing by: avg
Reviewed by: scottl
1) Move the new field (brand_note) to the end of the Brandinfo structure.
2) Add a new flag BI_BRAND_NOTE that indicates that the brand_note pointer
is valid.
3) Use the brand_note field if the flag BI_BRAND_NOTE is set and as old
modules won't have the flag set, so the new field brand_note would be
ignored.
Suggested by: jhb
Reviewed by: jhb
Approved by: kib (mentor)
MFC after: 6 days
to the full path of the image that is being executed.
Increase AT_COUNT.
Remove no longer true comment about types used in Linux ELF binaries,
listed types contain FreeBSD-specific entries.
Reviewed by: kan
".note.ABI-tag" section.
The search order of a brand is changed, now first of all the
".note.ABI-tag" is looked through.
Move code which fetch osreldate for ELF binary to check_note() handler.
PR: 118473
Approved by: kib (mentor)
offset. This is needed for the ehci hardware buffer rings that assume
this behavior.
This is an interim solution, and a more general one is being worked
on. This solution doesn't break anything that doesn't ask for it
directly. The mbuf and uio variants with this flag likely don't work
and haven't been tested.
Universe builds with these changes. I don't have a huge-memory
machine to test these changes with, but will be happy to work with
folks that do and hps if this changes turns out not to be sufficient.
Submitted by: alfred@ from Hans Peter Selasky's original
while holding a spin mutex. Instead, it now shoves the machine check
records onto a queue that is later drained to add sysctl nodes for each
record. While a routine to drain the queue is present, it is not currently
called.
Reviewed by: marcel
Sgtty is a programming interface that has been replaced by termios over
the years. In June we already removed <sgtty.h>, which exposes the
ioctl()'s that are implemented by this interface. The importance of this
flag is overrated right now.
of the ABI of the currently executing image. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures to determine ABI features.
Discussed with: dchagin, imp, jhb, peter
and ifnet functions
- add memory barriers to <machine/atomic.h>
- update drivers to only conditionally define their own
- add lockless producer / consumer ring buffer
- remove ring buffer implementation from cxgb and update its callers
- add if_transmit(struct ifnet *ifp, struct mbuf *m) to ifnet to
allow drivers to efficiently manage multiple hardware queues
(i.e. not serialize all packets through one ifq)
- expose if_qflush to allow drivers to flush any driver managed queues
This work was supported by Bitgravity Inc. and Chelsio Inc.
all to date and the latter also is only used in ia64 and powerpc
code which no longer serves a real purpose after bring-up and just
can be removed as well. Note that architectures like sun4u also
provide no means of implementing IPI'ing a CPU itself natively
in the first place.
Suggested by: jhb
Reviewed by: arch, grehan, jhb
After I removed all the unit2minor()/minor2unit() calls from the kernel
yesterday, I realised calling minor() everywhere is quite confusing.
Character devices now only have the ability to store a unit number, not
a minor number. Remove the confusion by using dev2unit() everywhere.
This commit could also be considered as a bug fix. A lot of drivers call
minor(), while they should actually be calling dev2unit(). In -CURRENT
this isn't a problem, but it turns out we never had any problem reports
related to that issue in the past. I suspect not many people connect
more than 256 pieces of the same hardware.
Reviewed by: kib
to the C99 style. At least, it is easier to read sysent definitions
that way, and search for the actual instances of sigcode etc.
Explicitely initialize sysentvec.sv_maxssiz that was missed in most
sysvecs.
No objection from: jhb
MFC after: 1 month
and bcmp are not the same thing. 'man bcmp' states that the return is
"non-zero" if the two byte strings are not identical. Where as,
'man memcmp' states that the return is the "difference between the
first two differing bytes (treated as unsigned char values" if the
two byte strings are not identical.
So provide a proper memcmp(9), but it is a C implementation not a tuned
assembly implementation. Therefore bcmp(9) should be preferred over memcmp(9).
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
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
Use the new inline function in ia64_invalidate_icache().
While there, add proper synchronization so that we know
the fc.i instructions have taken effect when we return.
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)
inlining resulted in constant propagation to the extend that cmpval
was known to the compiler to be URWLOCK_WRITE_OWNER (= 0x80000000U).
Unfortunately, instead of zero-extending the unsigned constant, it
was sign-extended. As such, the cmpxchg instruction was comparing
0x0000000080000000LU to 0xffffffff80000000LU and obviously didn't
perform the exchange.
But, since the value returned by cmpxhg equalled cmpval (when zero-
extended), the _thr_rtld_lock_release() function thought the exchange
did happen and as such returned as if having released the lock. This
was not the case. Subsequent locking requests found rw_state non-zero
and the thread in question entered the kernel and block indefinitely.
The work-around is to zero-extend by casting to uint64_t.
hard limit of 512 pending mutexes in the witness code and
we can easily have 1 million bucket mutexes initialized before
witness is up and running. Bumping the limit from 512 to 1M
is not really an option here...
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.
inittodr() and resettodr(). Have nexus double as the clock device,
because it's the firmware that provides RTC services. We could
create a special (pseudo-) device for it, but that wasn't superior
enough to actually do it. Maybe later...
Requested by: phk
o Implement IPI_PREEMPT,
o Set td_lock for the thread being switched out,
o For ULE & SMP, loop while td_lock points to blocked_lock for
the thread being switched in,
o Enable ULE by default in GENERIC and SKI,
(i.e. fixed delivery) to SAPIC_DELMODE_LOWPRI. While the commit
log doesn't mention the change in behaviour, it is believed to be
deliberate. In the last 5.5 years this hasn't been a problem. Nor
do I think did it make any difference, but who knows. However, I
do know that it break SMP support for Montecito-based machines.
Switch back to fixed-CPU delivery so that SMP works again. This
gives me some time to look more closely at the problem, as well
as make sure the I-cache validation as it's implemented currently
is sufficient in SMP configurations...
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
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
was a kluge. This implementation matches the behaviour on powerpc
and sparc64.
While on the subject, make sure to invalidate the I-cache after
loading a kernel module.
MFC after: 2 weeks
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.
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].
- 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
all. The reference in ia64 code is due to cutNpaste in its history
and can safely be removed.
Revired by: cognet, raj, marcel, jhb and maybe one other whom I'm forgetting
- 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}
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@
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.
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
coherent with the data caches. Implement a quick fix to allow
us to boot on Montecito, while I'm working on a better fix in
the mean time.
Commit made on Montecito-based Itanium...
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.
o Disklabels can have between 8 and 20 partitions (inclusive).
o No device special file is created for the raw partition.
o Switch ia64 to use this backend.
o No support for boot code yet.
- 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)
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
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.
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
This avoids back-to-back faults for all TLB misses. This can be
improved further in the future by also setting PTE_DIRTY for TLB
misses for write accesses.
MFC after: 1 week
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)
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)
Recently the AP in my Merced box seems to have grown a habit
of getting unexpected interrupts, such as redundant wake-ups
and legacy interrupts that require an INTA cycle.
While here, replace DELAY(0) with cpu_spinwait() so that it's
clear what we're doing as well as enable the code to take
advantage of cpu_spinwait() when it gets implemented.
Approved by: re (blanket)
There's no advantage in allowing nested external interrupts.
In fact, it leads to a potential stack overrun.
While here, put the interrupt vector in the trapframe, so as
to compensate for the 36 cycle latency of reading cr.ivr.
Further simplify assembly code by dealing with ASTs from C.
Approved by: re (blanket)
us to do the data serializations once after writing multiple
region registers, as is done in pmap_switch(). All existing
calls to ia64_set_rr() are followed with calls to ia64_srlz_d().
Approved by: re (blanket)
ia64_cpu.h. This improves readability and consistency and aids in
auditing the code.
Add instruction-serialization after writing to cr.pta.
Delay enabling interrupts until after we setup the clocks and after
we program the task priority register.
Approved by: re (blanket)
ia64_cpu.h. This improves readability and consistency and aids in
auditing the code.
Add data-serialization after writing to the region registers and
add instruction-serialization after writing to cr.pta.
Approved by: re (blanket)
ia64_cpu.h. This improves readability and consistency and aids in
auditing the code.
Add data-serialization after writing to cr.tpr.
Approved by: re (blanket)
bucket pointer. The virtual mapping may not be present in the
translation cache. This will result in a nested TLB fault at
a place we don't handle (and don't want to handle).
o Make sure there's a stop after the rfi instruction, otherwise
its behaviour is undefined.
o Make sure we switch back to virtual addressing before doing
a rfi. Behaviour is undefined otherwise.
Approved by: re (blanket)
(INTR_FILTER). This includes:
o Save a pointer to the sapic structure and IRQ for every vector,
so that we can quickly EOI, mask and unmask the interrupt.
o Add locking to the sapic code now that we can reprogram a
sapic on multiple CPUs at the same time.
o Use u_int for the vector and IRQ. We only have 256 vectors, so
using a 64-bit type for it is rather excessive.
o Properly handle concurrent registration of a handler for the
same vector.
Since vectors have a corresponding priority, we should not map
IRQs to vectors in a linear fashion, but rather pick a vector
that has a priority in line with the interrupt type. This is left
for later. The vector/IRQ interchange has been untangled as much
as possible to make this easier.
Approved by: re (blacket)
merely lucky that the VHPT was mapped as a side-effect of
mapping the kernel, but when there's enough physical memory,
this may not at all be the case.
Approved by: re (blanket)
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
The SDM states that writing to ar.bspstore invalidates the ar.rnat
register as a side-effect. This was interpreted as "bits in the
ar.rnat register that correspond to registers whose value is on
the stack are undefined'. Since we keep the kernel stack NaT-
aligned with the user stack (i.e. the lower 9 bits of the backing
store pointer remain unchanged when we switch to the kernel stack)
bits that need preserving would be preserved.
That interpretation is questionable. So, now, the interpretation
is more absolute: ar.rnat is undefined after writing to ar.bspstore.
As such, we write the saved value of ar.rnat back to ar.rnat after
writing to ar.bspstore.
Discussed with: christian.kandeler@hob.de
Approved by: re (kensmith)
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
is really a memory mapped I/O address. The bug is in the GAS that
describes the address and in particular the SpaceId field. The field
should not say the address is an I/O port when it clearly is not.
With an additional check for the IA64_BUS_SPACE_IO case in the bus
access functions, and the fact that I/O ports pretty much not used
in general on ia64, make the calculation of the I/O port address a
function. This avoids inlining the work-around into every driver,
and also helps reduce overall code bloat.
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.
grab sched_lock. This would serialize calls to pmap_switch from
cpu_switch(). With the introduction of thread_lock, this is not
possible anymore, because thread_lock is not a single lock. It
varies. Secondly and most importantly, it's not needed at all. The
only requirement for pmap_switch() is that it's not preempted
while in the middle of updating the CPU and PCPU. In other words,
it's a critical region. No locking required.
- 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)
- Add a new parameter to cpu_switch() that is used to release the lock on
the outgoing thread and properly acquire the lock on the incoming
thread. This parameter is not required for schedulers that don't do
per-cpu locking and architectures which do not support it may continue
to use the 4BSD scheduler. This feature is presently not supported
on ia64
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)
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
speculative loads. This at least makes control speculative loads
work. In the future we should analyze which faults/exceptions
we want to handle rather than defer to avoid having to call the
recovery code when it's not strictly necessary.
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.
processor is to jump to recovery code. This branching behaviour
may not be implemented by the processor and a Speculative Operation
fault is raised. The OS is responsible to emulate the branch.
Implement this, because GCC 4.2 uses advanced loads regularly.
scheme allowed for 1024 PTE pages, each containing 256 PTEs.
This yielded 2GB of KVA. This is not enough to boot a kernel
on a 16GB box and in general too low for a 64-bit machine.
By adding a level of indirection we now have 1024 2nd-level
directory pages, each capable of supporting 2GB of KVA. This
brings the grand total to 2TB of KVA.
Fix the flags argument: M_WAITOK is not a valid flag. Its presence
leaves the indication that contigmalloc(9) will not return a NULL
pointer.
The use of contigmalloc(9) in this place is probably not a good idea
given the constraints. It's probably better to lift the constraints
and instead add a permanent mapping to the ITR. It's possible that
the first 256MB of memory is exhausted when we get here.
This fixes a kernel panic on a 16GB rx3600.
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>
