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>
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
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
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.
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.
vm_page_alloc() from within a critical section in pmap_growkernel().
Since the need for a critical section may never have existed in the
first place, simply get rid of it.
Discussed with: alc@
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.
running thread's id on each cpu. This allow us to add in-kernel adaptive
spin for user level mutex. While spinning in user space is possible,
without correct thread running state exported from kernel, it hardly
can be implemented efficiently without wasting cpu cycles, however
exporting thread running state unlikely will be implemented soon as
it has to design and stablize interfaces. This implementation is
transparent to user space, it can be disabled dynamically. With this
change, mutex ping-pong program's performance is improved massively on
SMP machine. performance of mysql super-smack select benchmark is increased
about 7% on Intel dual dual-core2 Xeon machine, it indicates on systems
which have bunch of cpus and system-call overhead is low (athlon64, opteron,
and core-2 are known to be fast), the adaptive spin does help performance.
Added sysctls:
kern.threads.umtx_dflt_spins
if the sysctl value is non-zero, a zero umutex.m_spincount will
cause the sysctl value to be used a spin cycle count.
kern.threads.umtx_max_spins
the sysctl sets upper limit of spin cycle count.
Tested on: Athlon64 X2 3800+, Dual Xeon 5130
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.
Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.
The ULE scheduler compiles again but I have no idea if it works.
The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.
Tested by David Xu, and Dan Eischen using libthr and libpthread.
Change the pc_pcb field from a pointer to struct pcb to struct pcb
so that sizeof(struct pcb) includes the PCB we use for IPI_STOP.
Statically declare early_pcb so that we don't have to allocate the
PCB for thread0. This way we can setup the PCPU before cninit()
and thus before we use printf().
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
it as a default.
For the record, the KDTRACE option caused _no_ additional source files
to be compiled in; certainly no CDDL source files. All it did was to
allow existing BSD licensed kernel files to include one or more CDDL
header files.
By removing this from DEFAULTS, the onus is on a kernel builder to add
the option to the kernel config, possibly by including GENERIC and
customising from there. It means that DTrace won't be a feature
available in FreeBSD by default, which is the way I intended it to be.
Without this option, you can't load the dtrace module (which contains
the dtrace device and the DTrace framework). This is equivalent to
requiring an option in a kernel config before you can load the linux
emulation module, for example.
I think it is a mistake to have DTrace ported to FreeBSD, but not
to have it available to everyone, all the time. The only exception
to this is the companies which distribute systems with FreeBSD embedded.
Those companies will customise their systems anyway. The KDTRACE
option was intended for them, and only them.
adds the hooks that DTrace modules register with, and adds a few functions
which have the dtrace_ prefix to allow the DTrace FBT (function boundary
trace) provider to avoid tracing because they are called from the DTtrace
probe context.
Unlike other forms of tracing and debug, DTrace support in the kernel
incurs negligible run-time cost.
I think the only reason why anyone wouldn't want to have kernel support
enabled for DTrace would be due to the license (CDDL) under which DTrace
is released.
a lock to prevent interspersed strings written from different CPUs
at the same time.
To avoid putting a buffer on the stack or having to malloc one,
space is incorporated in the per-cpu structure. The buffer
size if 128 bytes; chosen because it's the next power of 2 size
up from 80 characters.
String writes to the console are buffered up the end of the line
or until the buffer fills. Then the buffer is flushed to all
console devices.
Existing low level console output via cnputc() is unaffected by
this change. ithread calls to log() are also unaffected to avoid
blocking those threads.
A minor change to the behaviour in a panic situation is that
console output will still be buffered, but won't be written to
a tty as before. This should prevent interspersed panic output
as a number of CPUs panic before we end up single threaded
running ddb.
Reviewed by: scottl, jhb
MFC after: 2 weeks
The 'nooption' kernel config entry has to be used to turn KSE off now.
This isn't my preferred way of dealing with this, but I'll defer to
scottl's experience with the io/mem kernel option change and the grief
experienced over that.
Submitted by: scottl@
except sun4v.
This change makes the transition from a default to an option more
transparent and is an attempt to head off all the compliants that are
likely from people who don't read UPDATING, based on experience with
the io/mem change.
Submitted by: scottl@
o day and mday are the same. No need to subtract 1 from mday.
o Set dow to -1 as clock_ct_to_ts() checks this field and
returns EINVAL on any day of the week but Sunday.
unsuspecting users.
- Add a comment in NOTES about experimental status of SCHED_ULE.
- Make warning about experimental status in sched_ule(4) a bit
stronger.
Suggested and reviewed by: dougb
Discussed on: developers
MFC after: 3 days
Submitted by:
Reviewed by:
Approved by:
Obtained from:
MFC after:
Security:
Move the relocation definitions to the common elf header so that DTrace
can use them on one architecture targeted to a different one.
Add the additional ELF types defines in Sun's "Linker and Libraries"
manual.
Split subr_clock.c in two parts (by repo-copy):
subr_clock.c contains generic RTC and calendaric stuff. etc.
subr_rtc.c contains the newbus'ified RTC interface.
Centralize the machdep.{adjkerntz,disable_rtc_set,wall_cmos_clock}
sysctls and associated variables into subr_clock.c. They are
not machine dependent and we have generic code that relies on being
present so they are not even optional.
WB (write-back) on x86 via control bits in PTEs and PDEs (including making
use of the PAT MSR). Changes include:
- A new pmap_mapdev_attr() function for amd64 and i386 which takes an
additional parameter (relative to pmap_mapdev()) specifying the cache
mode for this mapping. Note that on amd64 only WB mappings are done with
the direct map, all other modes result in a private mapping.
- pmap_mapdev() on i386 and amd64 now defaults to using UC (uncached)
mappings rather than WB. Previously we relied on the BIOS setting up
MTRR's to enforce memio regions being treated as UC. This might make
hw.cbb_start_memory unnecessary in some cases now for example.
- A new pmap_mapbios()/pmap_unmapbios() API has been added to allow places
that used pmap_mapdev() to map non-device memory (such as ACPI tables)
to do so using WB as before.
- A new pmap_change_attr() function for amd64 and i386 that changes the
caching mode for a range of KVA.
Reviewed by: alc
Originally, I had adopted sparc64's name, pmap_clear_write(), for the
function that is now pmap_remove_write(). However, this function is more
like pmap_remove_all() than like pmap_clear_modify() or
pmap_clear_reference(), hence, the name change.
The higher-level rationale behind this change is described in
src/sys/amd64/amd64/pmap.c revision 1.567. The short version is that I'm
trying to clean up and fix our support for execute access.
Reviewed by: marcel@ (ia64)
and pc98 MD files. Remove nodevice and nooption lines specific
to sio(4) from ia64, powerpc and sparc64 NOTES. There were no
such lines for arm yet.
sio(4) is usable on less than half the platforms, not counting
a future mips platform. Its presence in MI files is therefore
increasingly becoming a burden.
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.
implementations and adjust some of the checks while I'm here:
- Add a new check to make sure we don't return from a syscall in a critical
section.
- Add a new explicit check before userret() to make sure we don't return
with any locks held. The advantage here is that we can include the
syscall number and name in syscall() whereas that info is not available
in userret().
- Drop the mtx_assert()'s of sched_lock and Giant. They are replaced by
the more general checks just added.
MFC after: 2 weeks
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer). So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt. Also, now that it's easy to do so,
enable paging by default for all ddb commands. Any command that wishes to
honor the quit flag can do so by checking db_pager_quit. Note that the
pager can also be effectively disabled by setting $lines to 0.
Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
terminates early.
- 'show intr' now actually checks the quit flag and terminates early.
1. Make the caller responsible for performing pmap_install(). This reduces
the number of times that pmap_install() is performed by
pmap_enter_object() from twice per page to twice overall.
2. Don't block if pmap_find_pte() is unable to allocate a PTE. If it did
block, then it might wind up mapping a cache page. Specifically, if
pmap_enter_quick_locked() slept when called from pmap_enter_object(), the
page daemon could change an active or inactive page into a cache page just
before it was to be mapped.
3. Bail out of pmap_enter_quick_locked() if pv entries aren't plentiful.
In other words, don't force the allocation of a pv entry if they aren't
readily available.
Reviewed by: marcel@
in 1999, and there are changes to the sysctl names compared to PR,
according to that discussion. The description is in sys/conf/NOTES.
Lines in the GENERIC files are added in commented-out form.
I'll attach the test script I've used to PR.
PR: kern/14584
Submitted by: babkin
an explicit comment that it's needed for the linuxolator. This is not the
case anymore. For all other architectures there was only a "KEEP THIS".
I'm (and other people too) running a COMPAT_43-less kernel since it's not
necessary anymore for the linuxolator. Roman is running such a kernel for a
for longer time. No problems so far. And I doubt other (newer than ia32
or alpha) architectures really depend on it.
This may result in a small performance increase for some workloads.
If the removal of COMPAT_43 results in a not working program, please
recompile it and all dependencies and try again before reporting a
problem.
The only place where COMPAT_43 is needed (as in: does not compile without
it) is in the (outdated/not usable since too old) svr4 code.
Note: this does not remove the COMPAT_43TTY option.
Nagging by: rdivacky
There is a race with the current locking scheme and removing
it should have no measurable performance impact.
This fixes page faults leading to panics in pmap_enter_quick_locked()
on amd64/i386.
Reviewed by: alc,jhb,peter,ps
the arm to compile without all the extras that don't appear, at least
not in the flavors of ARM I deal with. This helps us save about 100k.
If I've botched the available devices on a platform, please let me
know and I'll correct ASAP.
that it just warns the user with a printf when it misaligns a piece
of memory that was requested through a busdma tag.
Some drivers (such as mpt, and probably others) were asking for alignments
that could not be satisfied, but as far as driver operation was concerned,
that did not matter. In the theory that other drivers will fall into
this same category, we agreed that panicing or making the allocation
fail will cause more hardship than is necessary. The printf should
be sufficient motivation to get the driver glitch fixed.
o Properly use rman(9) to manage resources. This eliminates the
need to puc-specific hacks to rman. It also allows devinfo(8)
to be used to find out the specific assignment of resources to
serial/parallel ports.
o Compress the PCI device "database" by optimizing for the common
case and to use a procedural interface to handle the exceptions.
The procedural interface also generalizes the need to setup the
hardware (program chipsets, program clock frequencies).
o Eliminate the need for PUC_FASTINTR. Serdev devices are fast by
default and non-serdev devices are handled by the bus.
o Use the serdev I/F to collect interrupt status and to handle
interrupts across ports in priority order.
o Sync the PCI device configuration to include devices found in
NetBSD and not yet merged to FreeBSD.
o Add support for Quatech 2, 4 and 8 port UARTs.
o Add support for a couple dozen Timedia serial cards as found
in Linux.
create managed mappings within the clean submap. To prevent regressions,
add assertions blocking the creation of managed mappings within the clean
submap.
Reviewed by: tegge
o use atomic operations to fiddle with stopped_cpus and started_cpus.
o disable interrupts while we're waiting to be started.
o remove logic relating to cpustop_restartfunc as it's not used.
PCB in which the context of stopped CPUs is stored. To access this
PCB from KDB, we introduce a new define, called KDB_STOPPEDPCB. The
definition, when present, lives in <machine/kdb.h> and abstracts
where MD code saves the context. Define KDB_STOPPEDPCB on i386,
amd64, alpha and sparc64 in accordance to previous code.
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.
Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week
pages, not a count of bytes. The sysctl handler for hw.realmem already
uses ctob() to convert realmem from pages to bytes. Thus, on archs that
were storing a byte count in the realmem variable, hw.realmem was inflated.
Reported by: Valerio daelli valerio dot daelli at gmail dot com (alpha)
MFC after: 3 days
save the MCA state of the AP. Saving the MCA state of the AP requires
us to allocate memory, which uses sleep locks.
Now that we correct the spinlock nesting of the AP without having
schedlock, avoid calling spinlock_exit(). Instead call critical_exit()
and manually clear the MD spinlock count.
MFC after: 3 days
Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly. Reduce it
from uint64_t to u_int.
Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret(). Use the absolute value of
td->pticks in userret() and eliminate third argument.
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.
For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines. (The main reason for this first milestone commit is
to verify that hypothesis.)
On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark. On more modern hardware no change
in performance is seen.
to COMPAT_43TTY.
Add COMPAT_43TTY to NOTES and */conf/GENERIC
Compile tty_compat.c only under the new option.
Spit out
#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.
param.h. Per request, I've placed these just after the
_NO_NAMESPACE_POLLUTION ifndef. I've not renamed anything yet, but
may since we don't need the __.
Submitted by: bde, jhb, scottl, many others.
- provide an interface (macros) to the page coloring part of the VM system,
this allows to try different coloring algorithms without the need to
touch every file [1]
- make the page queue tuning values readable: sysctl vm.stats.pagequeue
- autotuning of the page coloring values based upon the cache size instead
of options in the kernel config (disabling of the page coloring as a
kernel option is still possible)
MD changes:
- detection of the cache size: only IA32 and AMD64 (untested) contains
cache size detection code, every other arch just comes with a dummy
function (this results in the use of default values like it was the
case without the autotuning of the page coloring)
- print some more info on Intel CPU's (like we do on AMD and Transmeta
CPU's)
Note to AMD owners (IA32 and AMD64): please run "sysctl vm.stats.pagequeue"
and report if the cache* values are zero (= bug in the cache detection code)
or not.
Based upon work by: Chad David <davidc@acns.ab.ca> [1]
Reviewed by: alc, arch (in 2004)
Discussed with: alc, Chad David, arch (in 2004)
with flags bitfield and set BI_CAN_EXEC_DYN flag for all brands that usually
allow executing elf dynamic binaries (aka shared libraries). When it is
requested to execute ET_DYN elf image check if this flag is on after we
know the elf brand allowing execution if so.
PR: kern/87615
Submitted by: Marcin Koziej <creep@desk.pl>
passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly. In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures. Basically,
all the archs were taking a trapframe and converting it into a clockframe
one way or another. Now they can just extract the PC and usermode values
directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
timecounter, call hardclock() directly. This removes an extra
conditional check from every clock interrupt on Alpha on the BSP.
There is probably room for even further pruning here by changing Alpha
to use the simplified timecounter we use on x86 with the lapic timer
since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
is false, so add a KASSERT() to that affect and remove a condition
to slightly optimize the non-lapic case.
- Change prototypeof arm_handler_execute() so that it's first arg is a
trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.
Tested on: alpha, amd64, arm, i386, ia64, sparc64
Reviewed by: bde (mostly)
means:
o Remove Elf64_Quarter,
o Redefine Elf64_Half to be 16-bit,
o Redefine Elf64_Word to be 32-bit,
o Add Elf64_Xword and Elf64_Sxword for 64-bit entities,
o Use Elf_Size in MI code to abstract the difference between
Elf32_Word and Elf64_Word.
o Add Elf_Ssize as the signed counterpart of Elf_Size.
MFC after: 2 weeks
- Move vtophys() macros next to vtopte() where vtopte() exists to match
comments above vtopte().
- Remove references to the alternate address space in the comment above
vtopte(). amd64 never had the alternate address space, and i386 lost it
prior to PAE support being added.
- s/entires/entries/ in comments.
Reviewed by: alc
MACHINE_ARCH and MACHINE). Their purpose was to be able to test
in cpp(1), but cpp(1) only understands integer type expressions.
Using such unsupported expressions introduced a number of subtle
bugs, which were discovered by compiling with -Wundef.
via the DEFAULTS kernel configs. This allows folks to turn it that option
off in the kernel configs if desired without having to hack the source.
This is especially useful since PUC_FASTINTR hangs the kernel boot on my
ultra60 which has two uart(4) devices hung off of a puc(4) device.
I did not enable PUC_FASTINTR by default on powerpc since powerpc does not
currently allow sharing of INTR_FAST with non-INTR_FAST like the other
archs.
'device mem' over from GENERIC to DEFAULTS to be consistent with i386 and
amd64. Additionally, on ia64 enable ACPI by default since ia64 requires
acpi.
reclamation synchronously from get_pv_entry() instead of
asynchronously as part of the page daemon. Additionally, limit the
reclamation to inactive pages unless allocation from the PV entry zone
or reclamation from the inactive queue fails. Previously, reclamation
destroyed mappings to both inactive and active pages. get_pv_entry()
still, however, wakes up the page daemon when reclamation occurs. The
reason being that the page daemon may move some pages from the active
queue to the inactive queue, making some new pages available to future
reclamations.
Print the "reclaiming PV entries" message at most once per minute, but
don't stop printing it after the fifth time. This way, we do not give
the impression that the problem has gone away.
Reviewed by: tegge
Previously, pvzone's initialization was split between pmap_init() and
pmap_init2(). This split initialization was the underlying cause of
some UMA panics during initialization. Specifically, if the UMA boot
pages was exhausted before the pvzone was fully initialized, then UMA,
through no fault of its own, would use an inappropriate back-end
allocator leading to a panic. (Previously, as a workaround, we have
increased the UMA boot pages.) Fortunately, there is no longer any
reason that pvzone's initialization cannot be completed in
pmap_init().
Eliminate a check for whether pv_entry_high_water has been initialized
or not from get_pv_entry(). Since pvzone's initialization is
completed in pmap_init(), this check is no longer needed.
Use cnt.v_page_count, the actual count of available physical pages,
instead of vm_page_array_size to compute the maximum number of pv
entries.
Introduce the vm.pmap.pv_entries tunable on alpha and ia64.
Eliminate some unnecessary white space.
Discussed with: tegge (item #1)
Tested by: marcel (ia64)
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
that caused a premature exit after calling a fast interrupt handler
and bypassing a much needed critical_exit() and the scheduling of
the interrupt thread for non-fast handlers. In short: unbreak :-)
and increase flexibility to allow various different approaches to be tried
in the future.
- Split struct ithd up into two pieces. struct intr_event holds the list
of interrupt handlers associated with interrupt sources.
struct intr_thread contains the data relative to an interrupt thread.
Currently we still provide a 1:1 relationship of events to threads
with the exception that events only have an associated thread if there
is at least one threaded interrupt handler attached to the event. This
means that on x86 we no longer have 4 bazillion interrupt threads with
no handlers. It also means that interrupt events with only INTR_FAST
handlers no longer have an associated thread either.
- Renamed struct intrhand to struct intr_handler to follow the struct
intr_foo naming convention. This did require renaming the powerpc
MD struct intr_handler to struct ppc_intr_handler.
- INTR_FAST no longer implies INTR_EXCL on all architectures except for
powerpc. This means that multiple INTR_FAST handlers can attach to the
same interrupt and that INTR_FAST and non-INTR_FAST handlers can attach
to the same interrupt. Sharing INTR_FAST handlers may not always be
desirable, but having sio(4) and uhci(4) fight over an IRQ isn't fun
either. Drivers can always still use INTR_EXCL to ask for an interrupt
exclusively. The way this sharing works is that when an interrupt
comes in, all the INTR_FAST handlers are executed first, and if any
threaded handlers exist, the interrupt thread is scheduled afterwards.
This type of layout also makes it possible to investigate using interrupt
filters ala OS X where the filter determines whether or not its companion
threaded handler should run.
- Aside from the INTR_FAST changes above, the impact on MD interrupt code
is mostly just 's/ithread/intr_event/'.
- A new MI ddb command 'show intrs' walks the list of interrupt events
dumping their state. It also has a '/v' verbose switch which dumps
info about all of the handlers attached to each event.
- We currently don't destroy an interrupt thread when the last threaded
handler is removed because it would suck for things like ppbus(8)'s
braindead behavior. The code is present, though, it is just under
#if 0 for now.
- Move the code to actually execute the threaded handlers for an interrrupt
event into a separate function so that ithread_loop() becomes more
readable. Previously this code was all in the middle of ithread_loop()
and indented halfway across the screen.
- Made struct intr_thread private to kern_intr.c and replaced td_ithd
with a thread private flag TDP_ITHREAD.
- In statclock, check curthread against idlethread directly rather than
curthread's proc against idlethread's proc. (Not really related to intr
changes)
Tested on: alpha, amd64, i386, sparc64
Tested on: arm, ia64 (older version of patch by cognet and marcel)
get a new pv under high system load where the available pv entries
have been exhausted before the pagedaemon has a chance to wake up
to reclaim some.
Prior to this, the NULL pointer dereference ended up causing
secondary panics with rather less than useful resulting tracebacks.
Reviewed by: alc, jhb
MFC after: 1 week
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
osf1_signal.c:1.41, amd64/amd64/trap.c:1.291, linux_socket.c:1.60,
svr4_fcntl.c:1.36, svr4_ioctl.c:1.23, svr4_ipc.c:1.18, svr4_misc.c:1.81,
svr4_signal.c:1.34, svr4_stat.c:1.21, svr4_stream.c:1.55,
svr4_termios.c:1.13, svr4_ttold.c:1.15, svr4_util.h:1.10,
ext2_alloc.c:1.43, i386/i386/trap.c:1.279, vm86.c:1.58,
unaligned.c:1.12, imgact_elf.c:1.164, ffs_alloc.c:1.133:
Now that Giant is acquired in uprintf() and tprintf(), the caller no
longer leads to acquire Giant unless it also holds another mutex that
would generate a lock order reversal when calling into these functions.
Specifically not backed out is the acquisition of Giant in nfs_socket.c
and rpcclnt.c, where local mutexes are held and would otherwise violate
the lock order with Giant.
This aligns this code more with the eventual locking of ttys.
Suggested by: bde
variable and returns the previous value of the variable.
Tested on: i386, alpha, sparc64, arm (cognet)
Reviewed by: arch@
Submitted by: cognet (arm)
MFC after: 1 week
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).
Modify all consumers of uprintf() and tprintf() to hold Giant around
calls into these functions. In most cases, this means adding an
acquisition of Giant immediately around the function. In some cases
(nfs_timer()), it means acquiring Giant higher up in the callout.
With these changes, UFS no longer panics on SMP when either blocks are
exhausted or inodes are exhausted under load due to races in the tty
code when running without Giant.
NB: Some reduction in calls to uprintf() in the svr4 code is probably
desirable.
NB: In the case of nfs_timer(), calling uprintf() while holding a mutex,
or even in a callout at all, is a bad idea, and will generate warnings
and potential upset. This needs to be fixed, but was a problem before
this change.
NB: uprintf()/tprintf() sleeping is generally a bad ideas, as is having
non-MPSAFE tty code.
MFC after: 1 week
This kernel config briefly describes some of the major MAC policies
available on FreeBSD. The hope is that this will raise the awareness
about MAC and get more people interested.
Discussed with: scottl
take the lock from interrupt context, which causes an implicit
lock order reversal. We've been using the lock carefully enough
that making it a spin lock should not be harmful.
was not invalidated if the PTE was not actually being removed. In
an UP kernel this didn't cause problems, because the new mapping
would preempt the old one. In an SMP kernel this could lead to the
use of stale translations when processes move between CPUs at the
"right" moment. This fixes the last of the obvious SMP problems
and it should be safe to enable SMP by default now.
o In pmap_remove_pte: minor code refactoring to avoid duplication.
o Test all PTE pointers against NULL. Don't use implicit boolean
tests.
o s/vhpt_base/pmap_vhpt_base/g
o s/vhpt_bucket/pmap_vhpt_bucket/g
o Declare the above in <machine/pmap.h>
o Move the vm.stats.vhpt.* sysctls to machdep.vhpt.*
o Create a tunable machdep.vhpt.log2size, with corresponding sysctl.
The tunable allows the user to specify the VHPT size from the loader.
o Don't keep track of the number of PTEs in the VHPT. Calculate the
population when necessary by iterating the buckets and summing up
the length of the buckets.
o Don't perform the tpa instruction with a bucket lock held. The
instruction can (theoretically) fault and locking is not needed.
is never 0, so one cannot test for a NULL pointer after a physical
address is translated into a virtual pointer with said macro. Instead,
keep the physical address around and test it against 0. Note that
this obviously implies that a PTE can never be allocated at physical
address 0. This isn't exactly guaranteed, but hasn't been a problem
so far. We test the physical address against 0 for as long as the ia64
port exists...
it to __MINSIGSTKSZ. Define MINSIGSTKSZ in <sys/signal.h>.
This is done in order to use MINSIGSTKSZ for the macro PTHREAD_STACK_MIN
in <pthread.h> (soon <limits.h>) without having to include the whole
<sys/signal.h> header.
Discussed with: bde
high FP registers. It was not that the IPI got lost due to the
perceived unreliability of the IPI delivery, but rather that the
IPI was not assigned a vector (ugh). Sending a 0 vector to a CPU
results in a stray external interrupt.
Add a KASSERT to ipi_send() to catch this. The initialization of
the IPIs could be better, but it's not at all sure what the future
of the code is. Avoid wasting a lot of time on something that is
going to be rewritten anyway.
o Allocate a VHPT per CPU. The VHPT is a hash table that the CPU
uses to look up translations it can't find in the TLB. As such,
the VHPT serves as a level 1 cache (the TLB being a level 0 cache)
and best results are obtained when it's not shared between CPUs.
The collision chain (i.e. the hash bucket) is shared between CPUs,
as all buckets together constitute our collection of PTEs. To
achieve this, the collision chain does not point to the first PTE
in the list anymore, but to a hash bucket head structure. The
head structure contains the pointer to the first PTE in the list,
as well as a mutex to lock the bucket. Thus, each bucket is locked
independently of each other. With at least 1024 buckets in the VHPT,
this provides for sufficiently finei-grained locking to make the
ssolution scalable to large SMP machines.
o Add synchronisation to the lazy FP context switching. We do this
with a seperate per-thread lock. On SMP machines the lazy high FP
context switching without synchronisation caused inconsistent
state, which resulted in a panic. Since the use of the high FP
registers is not common, it's possible that races exist. The ia64
package build has proven to be a good stress test, so this will
get plenty of exercise in the near future.
o Don't use the local ID of the processor we want to send the IPI to
as the argument to ipi_send(). use the struct pcpu pointer instead.
The reason for this is that IPI delivery is unreliable. It has been
observed that sending an IPI to a CPU causes it to receive a stray
external interrupt. As such, we need a way to make the delivery
reliable. The intended solution is to queue requests in the target
CPU's per-CPU structure and use a single IPI to inform the CPU that
there's a new entry in the queue. If that IPI gets lost, the CPU
can check it's queue at any convenient time (such as for each
clock interrupt). This also allows us to send requests to a CPU
without interrupting it, if such would be beneficial.
With these changes SMP is almost working. There are still some random
process crashes and the machine can hang due to having the IPI lost
that deals with the high FP context switch.
The overhead of introducing the hash bucket head structure results
in a performance degradation of about 1% for UP (extra pointer
indirection). This is surprisingly small and is offset by gaining
reasonably/good scalable SMP support.
allocating a VHPT per CPU. Since we don't yet know how many CPUs
are actually in the system at the time we need to allocate the
VHPTs, we allocate for MAXCPU processors. This can result in a
lot of wasted space for 2-way machines. So, for now, limit MAXCPU
to something smaller until we have something more dynamic.
variables rather than void * variables. This makes it easier and simpler
to get asm constraints and volatile keywords correct.
MFC after: 3 days
Tested on: i386, alpha, sparc64
Compiled on: ia64, powerpc, amd64
Kernel toolchain busted on: arm
address, writting non-canonical address can cause kernel a panic,
by restricting base values to 0..VM_MAXUSER_ADDRESS, ensuring
only canonical values get written to the registers.
Reviewed by: peter, Josepha Koshy < joseph.koshy at gmail dot com >
Approved by: re (scottl)
This case is triggered with ptrace(2) and the PT_SETREGS function.
Change the return type of the function to int so that errors can be
passed on to the caller.
Approved by: re (scottl)
pointer doesn't point to the first instruction of that function, but
rather to a descriptor. The descriptor has the address of the first
instruction, as well as the value of the global pointer. The symbol
table doesn't know anything about descriptors, so if you lookup the
name of a function you get the address of the first instruction. The
cast from the address, which is the result of the symbol lookup, to a
function pointer as is done in db_fncall is therefore invalid.
Abstract this detail behind the DB_CALL macro. By default DB_CALL is
defined as db_fncall_generic, which yields the old behaviour. On ia64
the macro is defined as db_fncall_ia64, in which a descriptor is
constructed to yield a valid function pointer.
While here, introduce DB_MAXARGS. DB_MAXARGS replaces the existing
(local) MAXARGS. The DB_MAXARGS macro can be defined by platforms to
create a convenient maximum. By default this will be the legacy 10.
On ia64 we define this macro to be 8, for 8 is the maximum number of
arguments that can be passed in registers. This avoids having to
implement spilling of arguments on the memory stack.
Approved by: re (dwhite)
by amd64 and i386: For buffered writes we collect data and write it
out a ${DEV_BSIZE}-sized block at a time. The fragsz variable is used
to keep track of how much data we have collected in the buffer so far
and it's reset to zero immediately after writing a block to the dump
device.
When the last, possibly partially filled buffer is flushed, we didn't
reset fragsz to 0 and as such would stop reflecting reality. Since we
currently only need to do buffered writes once, this isn't a problem.
However, when kernel dumps are made by hand (say by callling doadump
from within DDB), the improperly cleared state from the first call to
dumpsys causes the next call to dumpsys to create an invalid code file.
This change resets fragsz after flushing the partially filled buffer so
that it fixes the two problems at once.
Approved by: re (scottl)
This is good enough to be able to run a RELENG_4 gdb binary against
a RELENG_4 application, along with various other tools (eg: 4.x gcore).
We use this at work.
ia32_reg.[ch]: handle the 32 bit register file format, used by ptrace,
procfs and core dumps.
procfs_*regs.c: vary the format of proc/XXX/*regs depending on the client
and target application.
procfs_map.c: Don't print a 64 bit value to 32 bit consumers, or their
sscanf fails. They expect an unsigned long.
imgact_elf.c: produce a valid 32 bit coredump for 32 bit apps.
sys_process.c: handle 32 bit consumers debugging 32 bit targets. Note
that 64 bit consumers can still debug 32 bit targets.
IA64 has got stubs for ia32_reg.c.
Known limitations: a 5.x/6.x gdb uses get/setcontext(), which isn't
implemented in the 32/64 wrapper yet. We also make a tiny patch to
gdb pacify it over conflicting formats of ld-elf.so.1.
Approved by: re
immediate is not saved by the architecture. Any of the break.{mifx}
instructions have their immediate saved in cr.iim on interruption.
Consequently, when we handle the break interrupt, we end up with a
break value of 0 when it was a break.b. The immediate is important
because it distinguishes between different uses of the break and
which are defined by the runtime specification.
The bottomline is that when the GNU debugger replaces a B-unit
instruction with a break instruction in the inferior, we would not
send the process a SIGTRAP when we encounter it, because the value
is not one we recognize as a debugger breakpoint.
This change adds logic to decode the bundle in which the break
instruction lives whenever the break value is 0. The assumption
being that it's a break.b and we fetch the immediate directly out
of the instruction. If the break instruction was not a break.b,
but any of break.{mifx} with an immediate of 0, we would be doing
unnecessary work. But since a break 0 is invalid, this is not a
problem and it will still result in a SIGILL being sent to the
process.
Approved by: re (scottl)
vm_page's machine-dependent fields. Use this function in
vm_pageq_add_new_page() so that the vm_page's machine-dependent and
machine-independent fields are initialized at the same time.
Remove code from pmap_init() for initializing the vm_page's
machine-dependent fields.
Remove stale comments from pmap_init().
Eliminate the Boolean variable pmap_initialized from the alpha, amd64,
i386, and ia64 pmap implementations. Its use is no longer required
because of the above changes and earlier changes that result in physical
memory that is being mapped at initialization time being mapped without
pv entries.
Tested by: cognet, kensmith, marcel
- Implement sampling modes and logging support in hwpmc(4).
- Separate MI and MD parts of hwpmc(4) and allow sharing of
PMC implementations across different architectures.
Add support for P4 (EMT64) style PMCs to the amd64 code.
- New pmcstat(8) options: -E (exit time counts) -W (counts
every context switch), -R (print log file).
- pmc(3) API changes, improve our ability to keep ABI compatibility
in the future. Add more 'alias' names for commonly used events.
- bug fixes & documentation.
in other codes. Add cpu_set_user_tls, use it to tweak user register
and setup user TLS. I ever wanted to merge it into cpu_set_kse_upcall,
but since cpu_set_kse_upcall is also used by M:N threads which may
not need this feature, so I wrote a separated cpu_set_user_tls.
o Remove the clock interface. Not only does it conflict with the MI
version when device genclock is added to the kernel, it was also
not possible to have more than 1 clock device. This of course would
have been a problem if we actually had more than 1 clock device.
In short: we don't need a clock interface and if we do eventually,
we should be using the MI one.
o Rewrite inittodr() and resettodr() to take into account that:
1) We use the EFI interface directly.
2) time_t is 64-bit and we do need to make sure we can determine
leap years from year 2100 and on. Add a nice explanation of
where leap years come from and why.
3) This rewrite happened in 2005 so any date prior to 1/1/2005
(either M/D/Y or D/M/Y) is bogus. Reprogram the EFI clock with
1/1/2005 in that case.
4) The EFI clock has a high probability of being correct, so
only (further) correct the EFI clock when the file system time
is larger. That should never happen in a time-synchronised world.
Complain when EFI lost 2 days or more.
Replace the copyright notice now that I (pretty much) rewrote all of
this file.
into _bus.h to help with name space polution from including all of bus.h.
In a few days, I'll commit changes to the MI code to take advantage of thse
sepration (after I've made sure that these changes don't break anything in
the main tree, I've tested in my trees, but you never know...).
Suggested by: bde (in 2002 or 2003 I think)
Reviewed in principle by: jhb
unw_step(). Both errors denote the end of a stack trace (i.e. no
prior frame), but are otherwise not error conditions.
Have db_trace() return 0 when the trace ends due to one of these
return codes as they are really normal termination conditions.
This change especially improves the output of the "show thread"
command in DDB when there are threads in fork_trampoline() and
previously db_trace() would return an error, causing the show
command to emit '***'.
MCA state requires a spin lock, which requires a valid curthread.
This change allows SMP kernels to boot into multi-user again.
While here, update the copyright notice and use __FBSDID for the
revision string.
1 Move the debug.clock_adjust_* sysctls to debug.clock.adjust_* to
make it easier to get only the clock statistics.
2 Make the sysctls read-only [suggested by Marius].
3 When determining the new clock adjustment, we checked for an error
either larger than 12.5% or smaller than 12.5%. We left out an error
of exactly 12.5%. For errors larger than 12.5% we adjust the clock
reload value in such a way that the next clock interrupt would be
early (as in premature). For errors less than 12.5% we stopped the
adjustment.
The current algorithm doesn't benefit from excluding an error of
exactly 12.5%. Change the code to stop adjusting the clock if the
error is *not* larger than 12.5% [suggested by Marius].
Discussed with: marius@
critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.
Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.
This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).
Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more
