Commit Graph

1402 Commits

Author SHA1 Message Date
marcel
1317d57d23 o Add missing relocations.
o  Minor white-space fixups.
2006-01-18 01:45:57 +00:00
marcel
408ca433c5 s/R_IA64_/R_IA_64_/g as per the ia64 psABI. 2006-01-17 21:03:22 +00:00
phk
57be8af642 Move the old BSD4.3 tty compatibility from (!BURN_BRIDGES && COMPAT_43)
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.
2006-01-10 09:19:10 +00:00
imp
c2b2965b6a By popular demand, move __HAVE_ACPI and __PCI_REROUTE_INTERRUPT into
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.
2006-01-09 06:05:57 +00:00
phk
44d6de75f9 Use ttyalloc() instead of ttymalloc() 2006-01-04 09:46:20 +00:00
imp
8d9b67a0e3 Define __HAVE_ACPI and/or __PCI_REROUTE_INTERRUPT, as appropriate for
each platform.  These will be used in the pci code in preference to
the complicated #ifdefs we have there now.
2006-01-01 20:59:28 +00:00
netchild
507a9b3e93 MI changes:
- 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)
2005-12-31 14:39:20 +00:00
sobomax
34fa5a81a5 Remove kern.elf32.can_exec_dyn sysctl. Instead extend Brandinfo structure
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>
2005-12-26 21:23:57 +00:00
jhb
cb0d490ebe Tweak how the MD code calls the fooclock() methods some. Instead of
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)
2005-12-22 22:16:09 +00:00
marcel
0a081d09f4 Make our ELF64 type definitions match standards. In particular this
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
2005-12-18 04:52:37 +00:00
jhb
0b37b8af54 - Cleanup whitespace and extra ()s in vtophys() macros.
- 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
2005-12-06 21:09:01 +00:00
ru
f9739084f5 Drop _MACHINE_ARCH and _MACHINE defines (not to be confused with
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.
2005-12-06 13:27:21 +00:00
ru
3db1ffb040 Fix -Wundef warnings from compiling GENERIC and LINT kernels of
all architectures.
2005-12-06 11:19:37 +00:00
ru
9fa3a162bc - Allow duplicate "machine" directives with the same arguments.
- Move existing "machine" directives to DEFAULTS.
2005-11-27 23:17:00 +00:00
jhb
80adaaedab Don't enable PUC_FASTINTR by default in the source. Instead, enable it
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.
2005-11-21 20:22:35 +00:00
jhb
23a1490fe0 Create DEFAULTS files for alpha, ia64, powerpc, and sparc64 and move
'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.
2005-11-21 20:17:46 +00:00
alc
b77df1e33a Eliminate pmap_init2(). It's no longer used. 2005-11-20 06:09:49 +00:00
alc
29e067429c In get_pv_entry() use PMAP_LOCK() instead of PMAP_TRYLOCK() when deadlock
cannot possibly occur.
2005-11-13 02:17:05 +00:00
alc
8852c8f9e2 Reimplement the reclamation of PV entries. Specifically, perform
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
2005-11-09 08:19:21 +00:00
alc
796bccfcad Begin and end the initialization of pvzone in pmap_init().
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)
2005-11-04 18:03:24 +00:00
alc
f044c16556 Remove the remaining spl*() calls. Add some assertions. Eliminate some
excessive white space.
2005-11-03 07:51:02 +00:00
rwatson
be4f357149 Normalize a significant number of kernel malloc type names:
- 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.
2005-10-31 15:41:29 +00:00
marcel
7c66d4d570 Remove a stray return statement in the interrupt dispatch function
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 :-)
2005-10-30 17:23:01 +00:00
jhb
e20e5c07ce Reorganize the interrupt handling code a bit to make a few things cleaner
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)
2005-10-25 19:48:48 +00:00
ade
25703033ca Specifically panic() in the case where pmap_insert_entry() fails to
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
2005-10-21 19:42:43 +00:00
phk
10f4dbda56 Make ttyconsolemode() call ttsetwater() so that drivers don't have to. 2005-10-16 20:58:22 +00:00
davidxu
3fbdb3c215 1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
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
2005-10-14 12:43:47 +00:00
phk
84cf732734 Eliminate need for __RMAN_RESOURCE_VISIBLE
Reviewed by:	marcel@
2005-10-06 17:39:18 +00:00
rwatson
2b01dbdaa0 Back out alpha/alpha/trap.c:1.124, osf1_ioctl.c:1.14, osf1_misc.c:1.57,
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
2005-09-28 07:03:03 +00:00
peter
fe69f6532f Implement 32 bit getcontext/setcontext/swapcontext on amd64. I've added
stubs for ia64 to keep it compiling.  These are used by 32 bit apps such
as gdb.
2005-09-27 18:04:20 +00:00
jhb
89caa56972 Add a new atomic_fetchadd() primitive that atomically adds a value to a
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
2005-09-27 17:39:11 +00:00
rwatson
c479a90eb8 Add GIANT_REQUIRED and WITNESS sleep warnings to uprintf() and tprintf(),
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
2005-09-19 16:51:43 +00:00
csjp
6216087b31 Introduce a kernel config for the Mandatory Access Control framework.
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
2005-09-18 03:15:36 +00:00
alc
4cfa27e2c0 Eliminate unused definitions. 2005-09-11 20:51:15 +00:00
obrien
5a7994d2cd Canonize the include of acpi.h. 2005-09-11 18:39:03 +00:00
marcel
0257724685 Merge db_interface.c and db_trace.c into db_machdep.c. 2005-09-10 03:18:51 +00:00
marcel
5c8a9dbf0f Move the prototypes of db_md_set_watchpoint(), db_md_clr_watchpoint()
and db_md_list_watchpoints() to ddb/ddb.h.
2005-09-10 03:01:25 +00:00
marcel
6798cfc6b5 Move the ia32_sigcode structure from ia32_sigtramp.c to ia32_signal.c.
It's a bit excessive to have it in a file of its own.
2005-09-10 02:12:49 +00:00
marcel
219ddde5ec Remove redundant $FreeBSD$ 2005-09-10 01:13:33 +00:00
marcel
e087d7c1f4 Change the High FP lock from a sleep lock to a spin lock. We can
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.
2005-09-09 19:18:36 +00:00
marcel
9a432bff04 Milestone: enable SMP by default. 2005-09-05 21:36:28 +00:00
marcel
b58a5b21d1 o In pmap_remove_pte: always invalidate the page. Previously the page
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.
2005-09-05 21:32:02 +00:00
marcel
1a76dde0ef o s/vhpt_size/pmap_vhpt_log2size/g
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.
2005-09-03 23:53:50 +00:00
marcel
516e4da61f Fix collision chain termination checks. The result of IA64_PHYS_TO_RR7
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...
2005-09-03 19:43:15 +00:00
alc
39788de49e Pass a value of type vm_prot_t to pmap_enter_quick() so that it determine
whether the mapping should permit execute access.
2005-09-03 18:20:20 +00:00
stefanf
78a1b1beb4 Move MINSIGSTKSZ from <machine/signal.h> to <machine/_limits.h> and rename
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
2005-08-20 16:44:41 +00:00
marcel
3b0e65cd6d Remove the execute permission for stacks. 2005-08-14 23:17:59 +00:00
marcel
05cc3bf3e7 o s/pmap_lpte_/pmap_/g
o  Remove pmap_is_referenced(). It was already compiled-out.
2005-08-13 21:16:38 +00:00
marcel
0bc686305b Fix the problem with the IPI for the lazy context switching of the
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.
2005-08-13 21:08:32 +00:00
marcel
c96864a4b2 Improve SMP support:
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.
2005-08-06 20:28:19 +00:00