when the bit 22 is set to 1, CPUID with EAX=0 returns a maximum
value in EAX[7..0] of 3, when set to 0(default), CPUID with EAX=0
returns the number corresponding to the maximum standard function
supported. On my machine, BIOS sets the bit to 1 to make it to be
compatible with old OS, this causes dual-core Pentium-D (two
physical cores) to be identified as hyperthreading (two logical
cores) by function mp_topology().
POSIX (susv3) requires this, but it is unclear what should be inherited,
duplicating whole 387 stack for new thread seems to be unnecessary and
dangerous. Revert to previous code, force a new thread to be started with
clean FP state.
per page = effectively 12.19 bytes per pv entry after overheads).
Instead of using a shared UMA zone for 24 byte pv entries (two 8-byte tailq
nodes, a 4 byte pointer, and a 4 byte address), we allocate a page at a
time per process. This provides 336 pv entries per process (actually, per
pmap address space) and eliminates one of the 8-byte tailq entries since
we now can track per-process pv entries implicitly. The pointer to
the pmap can be eliminated by doing address arithmetic to find the metadata
on the page headers to find a single pointer shared by all 336 entries.
There is an 11-int bitmap for the freelist of those 336 entries.
This is mostly a mechanical conversion from amd64, except:
* i386 has to allocate kvm and map the pages, amd64 has them outside of kvm
* native word size is smaller, so bitmaps etc become 32 bit instead of 64
* no dump_add_page() etc stuff because they are in kvm always.
* various pmap internals tweaks because pmap uses direct map on amd64 but
on i386 it has to use sched_pin and temporary mappings.
Also, sysctl vm.pmap.pv_entry_max and vm.pmap.shpgperproc are now
dynamic sysctls. Like on amd64, i386 can now tune the pv entry limits
without a recompile or reboot.
This is important because of the following scenario. If you have a 1GB
file (262144 pages) mmap()ed into 50 processes, that requires 13 million
pv entries. At 24 bytes per pv entry, that is 314MB of ram and kvm, while
at 12 bytes it is 157MB. A 157MB saving is significant.
Test-run by: scottl (Thanks!)
Major differences:
* since there is no direct map region, there is no custom uma memory
allocator to modify to include its pages in the dumps.
* Various data entries are reduced from 64 bit to 32 bit to match the
native size.
dump_add_page() and dump_drop_page() are still present in case one wants to
arrange for arbitary pages to be dumped. This is of marginal use though
because libkvm+kgdb cannot address physical memory that isn't mapped into
kvm.
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.
- Throw out all of the logical APIC ID stuff. The Intel docs are somewhat
ambiguous, but it seems that the "flat" cluster model we are currently
using is only supported on Pentium and P6 family CPUs. The other
"hierarchy" cluster model that is supported on all Intel CPUs with
local APICs is severely underdocumented. For example, it's not clear
if the OS needs to glean the topology of the APIC hierarchy from
somewhere (neither ACPI nor MP Table include it) and setup the logical
clusters based on the physical hierarchy or not. Not only that, but on
certain Intel chipsets, even though there were 4 CPUs in a logical
cluster, all the interrupts were only sent to one CPU anyway.
- We now bind interrupts to individual CPUs using physical addressing via
the local APIC IDs. This code has also moved out of the ioapic PIC
driver and into the common interrupt source code so that it can be
shared with MSI interrupt sources since MSI is addressed to APICs the
same way that I/O APIC pins are.
- Interrupt source classes grow a new method pic_assign_cpu() to bind an
interrupt source to a specific local APIC ID.
- The SMP code now tells the interrupt code which CPUs are avaiable to
handle interrupts in a simpler and more intuitive manner. For one thing,
it means we could now choose to not route interrupts to HT cores if we
wanted to (this code is currently in place in fact, but under an #if 0
for now).
- For now we simply do static round-robin of IRQs to CPUs when the first
interrupt handler just as before, with the change that IRQs are now
bound to individual CPUs rather than groups of up to 4 CPUs.
- Because the IRQ to CPU mapping has now been moved up a layer, it would
be easier to manage this mapping from higher levels. For example, we
could allow drivers to specify a CPU affinity map for their interrupts,
or we could allow a userland tool to bind IRQs to specific CPUs.
The MFC is tentative, but I want to see if this fixes problems some folks
had with UP APIC kernels on 6.0 on SMP machines (an SMP kernel would work
fine, but a UP APIC kernel (such as GENERIC in RELENG_6) would lose
interrupts).
MFC after: 1 week
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.
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)
- 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.
rather than embedding it in the intrframe as if_vec. This reduces diffs
with amd64 somewhat.
- Remove cf_vec from clockframe (it wasn't used anyway) and stop pushing
dummy vector arguments for ipi_bitmap_handler() and lapic_handle_timer()
since clockframe == trapframe now.
- Fix ddb to handle stack traces across interrupt entry points that just
have a trapframe on their stack and not a trapframe + vector.
- Change intr_execute_handlers() to take a trapframe rather than an
intrframe pointer.
- Change lapic_handle_intr() and atpic_handle_intr() to take a vector and
trapframe rather than an intrframe.
- GC struct intrframe now that nothing uses it anymore.
- GC CLOCK_TO_TRAPFRAME() and INTR_TO_TRAPFRAME().
Reviewed by: bde
Requested by: peter
ipi_nmi_handler() and into a new cpustop_handler() function. Change
the Xcpustop IPI_STOP handler to call this function instead of
duplicating all the same logic in assembly.
- EOI the local APIC for the lapic timer interrupt in C rather than
assembly.
- Bump the lazypmap IPI counter if COUNT_IPIS is defined in C rather than
assembly.
- Add a new SET_KERNEL_SREGS macro that sets up %ds and %es to point to
kernel data and %fs to point to per-CPU data and use the new macro
in several kernel entry points including trap and interrupt handlers.
- Convert the IPI_STOP handler Xcpustop to push a standard trap frame
rather than an application frame.
- Make the TRAP() macro private to exception.s since it is only used
there.
- Move the PCPU_*() macros in asmacros.h out of the middle of the
profiling macros.
Reviewed by: bde
Requested by: bde (4, 5)
during SMP startup. We haven't had any issues with starting up the APs
on i386 in quite a while now which is all this code is really useful for.
If someone ever does really need it they can always dig it up out of the
attic.
The following repo-copies were made (by Mark Murray):
sys/i386/isa/spkr.c -> sys/dev/speaker/spkr.c
sys/i386/include/speaker.h -> sys/dev/speaker/speaker.h
share/man/man4/man4.i386/spkr.4 -> share/man/man4/spkr.4
nearly identical to wintel/ia32, with a couple of tweaks. Since it is
so similar to ia32, it is optionally added to a i386 kernel. This
port is preliminary, but seems to work well. Further improvements
will improve the interaction with syscons(4), port Linux nforce driver
and future versions of the xbox.
This supports the 64MB and 128MB boxes. You'll need the most recent
CVS version of Cromwell (the Linux BIOS for the XBOX) to boot.
Rink will be maintaining this port, and is interested in feedback.
He's setup a website http://xbox-bsd.nl to report the latest
developments.
Any silly mistakes are my fault.
Submitted by: Rink P.W. Springer rink at stack dot nl and
Ed Schouten ed at fxq dot nl
source is first enabled similar to how intr_event's now allocate ithreads
on-demand. Previously, we would map IDT vectors 1:1 to IRQs. Since we
only have 191 available IDT vectors for I/O interrupts, this limited us
to only supporting IRQs 0-190 corresponding to the first 190 I/O APIC
intpins. On many machines, however, each PCI-X bus has its own APIC even
though it only has 1 or 2 devices, thus, we were reserving between 24 and
32 IRQs just for 1 or 2 devices and thus 24 or 32 IDT vectors. With this
change, a machine with 100 IRQs but only 5 in use will only use up 5 IDT
vectors. Also, this change provides an API (apic_alloc_vector() and
apic_free_vector()) that will allow a future MSI interrupt source driver to
request IDT vectors for use by MSI interrupts on x86 machines.
Tested on: amd64, i386
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)
IPI_STOP IPIs.
- Change the i386 and amd64 MD IPI code to send an NMI if STOP_NMI is
enabled if an attempt is made to send an IPI_STOP IPI. If the kernel
option is enabled, there is also a sysctl to change the behavior at
runtime (debug.stop_cpus_with_nmi which defaults to enabled). This
includes removing stop_cpus_nmi() and making ipi_nmi_selected() a
private function for i386 and amd64.
- Fix ipi_all(), ipi_all_but_self(), and ipi_self() on i386 and amd64 to
properly handle bitmapped IPIs as well as IPI_STOP IPIs when STOP_NMI is
enabled.
- Fix ipi_nmi_handler() to execute the restart function on the first CPU
that is restarted making use of atomic_readandclear() rather than
assuming that the BSP is always included in the set of restarted CPUs.
Also, the NMI handler didn't clear the function pointer meaning that
subsequent stop and restarts could execute the function again.
- Define a new macro HAVE_STOPPEDPCBS on i386 and amd64 to control the use
of stoppedpcbs[] and always enable it for i386 and amd64 instead of
being dependent on KDB_STOP_NMI. It works fine in both the NMI and
non-NMI cases.
- Add newer CPUID definitions for future use.
Many thanks to Mike Tancsa <mike at sentex dot net> for providing test
cases for Intel Pentium D and AMD Athlon 64 X2.
Approved by: anholt (mentor)
can be enabled by enabling COUNT_IPIS in smptests.h. When enabled, each
CPU provides an interrupt counter for nearly all of the IPIs it receives
(IPI_STOP currently doesn't have a counter) that can be examined using
vmstat -i, etc.
MFC after: 3 days
Requested by: rwatson
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
