- Do not cover error returned by pmc_core_initialize with the
result of pmc_uncore_initialize, fail right away.
- Give a user something to report instead failing silently
Reported by: Alexandr Kovalenko <never@nevermind.kiev.ua>
The on-chip SD slots do not have PCI BARs corresponding to them, so
this has to be handled in the custom SoC memory allocation.
Provide memory resource for rids corresponding to BAR 0 and 1 in
the custom allocation code.
The XLP on-chip devices have PCI configuration headers, but some of the
devices need custom resource allocation code.
- devices with no MEM/IO BARs with registers in PCIe extended reg
space have to be handled in memory resource allocation
- devices without INTPIN/INTLINE in PCI header can be supported
by having these faked with a shadow register.
- Some devices does not allow 8/16 bit access to the register space,
he default bus space cannot be used for these.
Subclass pci and override attach and resource allocation methods to
take care of this.
Remove earlier code which did this partially.
Temporarily revert an upstream commit. This change caused regressions for
too many laptop users. Especially, automatic repair for broken _BIF caused
strange reference counting issues and kernal panics. This reverts:
c995fed15a
SCTP will only do IPv4 UDP checksum calculation as defined by the host
policy. When tunneling SCTP always calculates the inner checksum already
so not doing the outer UDP can save cycles.
While here virtualize the variable.
Requested by: tuexen
MFC after: 2 weeks
The flash commands and responses are little-endian and have to be
byte swapped on big-endian systems. However the raw read of data
need not be swapped.
Make the cfi_read and cfi_write do the swapping, and provide a
cfi_read_raw which does not byte swap for reading data from
flash.
loaded and unloaded, also have sdt.ko register callbacks with kern_sdt.c
that will be called when a newly loaded KLD module adds more probes or
a module with probes is unloaded.
This fixes two issues: first, if a module with SDT probes was loaded after
sdt.ko was loaded, those new probes would not be available in DTrace.
Second, if a module with SDT probes was unloaded while sdt.ko was loaded,
the kernel would panic the next time DTrace had cause to try and do
anything with the no-longer-existent probes.
This makes it possible to create SDT probes in KLD modules, although there
are still two caveats: first, any SDT probes in a KLD module must be part
of a DTrace provider that is defined in that module. At present DTrace
only destroys probes when the provider is destroyed, so you can still
panic the system if a KLD module creates new probes in a provider from a
different module(including the kernel) and then unload the the first module.
Second, the system will panic if you unload a module containing SDT probes
while there is an active D script that has enabled those probes.
MFC after: 1 month
Move XLP PCI UART device to sys/mips/nlm/dev/ directory. Other
drivers for the XLP SoC devices will be added here as well.
Update uart_cpu_xlp.c and uart_pci_xlp.c use macros for uart port,
speed and IO frequency.
Features:
- network driver for the four 10G interfaces and two management ports
on XLP 8xx.
- Support 4xx and 3xx variants of the processor.
- Source code and firmware building for the 16 mips32r2 micro-code engines
in the Network Accelerator.
- Basic initialization code for Packet ordering Engine.
Submitted by: Prabhath Raman (prabhath at netlogicmicro com)
[refactored and fixed up for style by jchandra]
On XLP evaluation platform, the board information is stored
in an I2C eeprom and the network block configuration is available
from a CPLD connected to the GBU (NOR flash bus). Add support
for both of these.
Support for the Security and RSA blocks on XLP SoC. Even though
the XLP supports many more algorithms, only the ones supported
in OCF have been added.
Submitted by: Venkatesh J. V. (venkatesh at netlogicmicro com)
Add a Simple polled driver iicoc for the OpenCores I2C controller. This
is used in Netlogic XLP processors.
Submitted by: Sreekanth M. S. (kanthms at netlogicmicro com)
The earlier version of the driver is sys/mips/rmi/dev/iic/ds1374u.c
Convert all references to ds1374u to ds1374, and use DEVMETHOD_END.
Also update the license header as Netlogic is now Broadcom.
- XLP supports hardware swap for PCIe IO/MEM accesses. Since we
are in big-endian mode, enable hardware swap and use the normal
bus space.
- move some printfs to bootverbose, and remove others.
- fix SoC device resource allocation code
- Do not use '|' while updating PCIE_BRIDGE_MSI_ADDRL
- some style fixes
In collaboration with: Venkatesh J. V. (venkatesh at netlogicmicro com)
Because the code lacks all the GNU extensions to printf() format stuff,
the compiler doesn't helpfully tell us that I messed up in a previous
commit.
Pointy hat to: adrian, who likely only cares about this because he's the
only one who bothers flipping on net80211 debugging.
uses of the page queues mutex with a new rwlock that protects the page
table and the PV lists. This reduces system time during a parallel
buildworld by 35%.
Reviewed by: alc
within the BAW.
This regression was introduced in ane earlier commit by me to fix the
BAW seqno allocation-but-not-insertion-into-BAW race. Since it was only
ever using the to-be allocated sequence number, any frame retries
with the first frame in the BAW still in the software queue would
have constantly failed, as ni_txseqs[tid] would always be outside
the BAW.
TODO:
* Extract out the mostly common code here in the agg and non-agg ADDBA
case and stuff it into a single function.
PR: kern/166357
Function acquired reader lock if needed.
Assert check for reader or writer lock (RA_LOCKED / RA_UNLOCKED)
- While here, add knlist_init_mtx.9 to MLINKS and fix some style(9) issues
Reviewed by: glebius
Approved by: ae(mentor)
MFC after: 2 weeks
I see traffic stalls.
It turns out that the bug isn't because the first and last frame in the
BAW is in the software queue. It is more likely that it's because
the first frame in the BAW is still in the software queue and thus there's
no more room to allocate and do subsequent TX.
PR: kern/166357
net.inet.ip.fw.tables_max is now read-write.
- Bump IPFW_TABLES_MAX to 65535
Default number of tables is still 128
- Remove IPFW_TABLES_MAX from ipfw(8) code.
Sponsored by Yandex LLC
Approved by: kib(mentor)
MFC after: 2 weeks
XenServer configurations that advertise the multi-page ring extension,
but only allow a single page of ring space.
sys/dev/xen/blkfront/blkfront.c:
If only one page of ring space is being used, do not publish
in the XenStore the number of pages in use (1), via either
of the supported multi-page ring extension schemes.
Single page operation is the same with or without the
ring-page extension being negotiated. Relying on the
legacy behavior avoids an incompatible difference in how
the two ring-page extension schemes that are out in the
wild, deal with the base case of a single page. The
Amazon/Red Hat drivers use the same XenStore variable as
if the extension was not negotiated. The Citrix drivers
assume the new ring reference XenStore variables will be
available
Reported by: Oliver Schonefeld <schonefeld@ids-mannheim.de>
MFC after: 3 days
This is not entirely correct as it simply resets the channel, flushing
whatever is in the TX/RX queue. This can and will break aggregation
BAW tracking. But the alternative (HT40 frames being sent with the hardware
in HT20 mode) is even worse.
There's still a small window between the htinfo being received (and the ni_chw
field being updated) which could cause problems. I'll look at fleshing this
out in follow-up commits.
PR: kern/166286
Currently, a channel width change updates the 802.11n HT info data in
net80211 but it doesn't trigger any device changes. So the device
driver may decide that HT40 frames can be transmitted but the last
device channel set only had HT20 set.
Now, a task is scheduled so a hardware reset or change isn't done
during any active ongoing RX. It also means that it's serialised
with the other task operations (eg channel change.)
This isn't the final incantation of this work, see below.
For now, any unmodified drivers will simply receive a channel
change log entry. A subsequent patch to ath(4) will introduce
some basic channel change handling (by resetting the NIC.)
Other NICs may need to update their rate control information.
TODO:
* There's still a small window at the present moment where the
channel width has been updated but the task hasn't been fired.
The final version of this should likely pass in a channel width
field to the driver and let the driver atomically do whatever
it needs to before changing the channel.
PR: kern/166286
<20120222095239.Horde.0hpYHJjmRSRPRKzXsoFRbYk@webmail.leidinger.net>.
According to some private emails received, it apparently is not unpopular
to use at least Quad GigaSwift cards driven by cas(4) in x86 machines.
MFC after: 1 week
order to avoid otherwise harmless witness warnings when these are acquired
at the same time and due to both using MTX_NETWORK_LOCK as their type.
The right fix actually would be to use different, descriptive types for
these. However, the latter would require undesirable changes to the shared
code base. Another approach would be to just supply NULL as the type, which
was deemed as less desirable though as it would cause the unique but cryptic
name also to be used for the type and to diverge from the type used by other
network device drivers.
MFC after: 1 week
DMA tag with a 4 GB boundary as required by PCI-Express. With r232403 in
place this actually is redundant. However, the host-PCI-Express bridge
driver is the more appropriate place for implementing this restriction.
MFC after: 3 days
recent changes in sys/x86/include/endian.h:
sys/dev/dcons/dcons.c:190:15: error: implicit conversion from '__uint32_t' (aka 'unsigned int') to '__uint16_t' (aka 'unsigned short') changes value from 1684238190 to 28526 [-Werror,-Wconstant-conversion]
buf->magic = ntohl(DCONS_MAGIC);
^~~~~~~~~~~~~~~~~~
sys/sys/param.h:306:18: note: expanded from:
#define ntohl(x) __ntohl(x)
^
./x86/endian.h:128:20: note: expanded from:
#define __ntohl(x) __bswap32(x)
^
./x86/endian.h:78:20: note: expanded from:
__bswap32_gen((__uint32_t)(x)) : __bswap32_var(x))
^
./x86/endian.h:68:26: note: expanded from:
(((__uint32_t)__bswap16(x) << 16) | __bswap16((x) >> 16))
^
./x86/endian.h:75:53: note: expanded from:
__bswap16_gen((__uint16_t)(x)) : __bswap16_var(x)))
~~~~~~~~~~~~~ ^
This is because the __bswapXX_gen() macros (for x86) call the regular
__bswapXX() macros. Since the __bswapXX_gen() variants are only called
when their arguments are constant, there is no need to do that constancy
check recursively. Also, it causes the above error with clang.
Fix it by calling __bswap16_gen() from __bswap32_gen(), and similarly,
__bswap32_gen() from __bswap64_gen().
While here, add extra parentheses around the __bswap16_gen() macro
expansion, to prevent unexpected side effects.
- header and stub .c file for fasttrap module. It's not supported on
MIPS yet, but there is no way to disable support completely
- Do as amd64 trying to limit allocated memory
Note that this driver additionally probes some device IDs for the most
part not know to other MPT drivers, if at all. So rename the macros not
present in mpi_cnfg.h to match the naming scheme in the latter and but
suffix them with a _FB in order to not cause conflicts.
- Like mpt_set_config_regs(), comment out mpt_read_config_regs() as the
content of the registers read isn't actually used and both functions
aren't exactly up to date regarding the possible layouts of the BARs
(these function might be helpful for debugging though, so don't remove
them completely).
- Use DEVMETHOD_END.
- Use NULL rather than 0 for pointers.
- Remove an unusual check for the softc being NULL.
- Remove redundant zeroing of the softc.
- Remove an overly banal and actually partly incorrect as well as partly
outdated comment regarding the allocation of the memory resource.
MFC after: 3 days
appropriate state handling takes place, not doing so results in the
device doing nothing until manual intervention.
Reviewed by: iwasaki
Tested by: iwasaki (iwi)
MFC after: 4 weeks
until domain discovery is complete. This fixes an isci(4) bug on FreeBSD 7.x
where devices weren't always appearing after boot without an explicit rescan.
Sponsored by: Intel
Reported and tested by: <rpokala at panasas dot com>
Reviewed by: scottl
Approved by: scottl
sys/dev/mps/mps_sas.c:861:1: error: function 'mpssas_discovery_timeout' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
mpssas_discovery_timeout(void *data)
^
Because the driver is obtained from upstream, we don't want to modify
it; just silence the warning instead, it is harmless.
MFC after: 3 days
KLD is preloaded with loader(8) and leads to infinity loops.
Also do not return EEXIST error code from MOD_LOAD handler, because
we have undocumented(?) ability replace kernel's module with preloaded one.
And if we have so, then preloaded module will be initialized first.
Thus error in MOD_LOAD handler will be triggered for the kernel.
PR: kern/165573
MFC after: 3 weeks
o Fix buffer overflows when using a long property body in node paths.
o Fix loop end condition when iterating through the symbol table.
o Better error handling during node modification, better problem reporting.
o Eliminate build time warnings.
Submitted by: Lukasz Wojcik
Obtained from: Semihalf
MFC after: 1 week
- Replace MIPS24K-specific code with more generic framework that will
make adding new CPU support easier
- Add MIPS24K support for new framework
- Limit backtrace depth to 1 for stability reasons and add option
HWPMC_MIPS_BACKTRACE to override this limitation
Sycall argument is pointer to array of register_t values. Casting it to
pointer to structure with fields of size smaller then register_t we rely
on compiler-dependent memory layout of structure.
Tested on: mips64 and amd64 systems
The GPL infected parts which were blocking the inclusion of snd_csa
and snd_emu10kx in GENERIC have recently been removed from the tree.
I'm also adding snd_cmi to GENERIC, which I originally intended to
add when we enabled sound support by default.
Discussed with: jhb, pfg, Yuriy Tsibizov <yuriy.tsibizov@gfk.ru>
Approved by: jhb
private to this file. The 'lapics' array was actually shadowing a
completely different 'lapics' array that is private to local_apic.c.
Reported by: bde
MFC after: 2 weeks
kernel.
When access restrictions are added to a page table entry, we flush the
corresponding virtual address mapping from the TLB. In contrast, when
access restrictions are removed from a page table entry, we do not
flush the virtual address mapping from the TLB. This is exactly as
recommended in AMD's documentation. In effect, when access
restrictions are removed from a page table entry, AMD's MMUs will
transparently refresh a stale TLB entry. In short, this saves us from
having to perform potentially costly TLB flushes. In contrast,
Intel's MMUs are allowed to generate a spurious page fault based upon
the stale TLB entry. Usually, such spurious page faults are handled
by vm_fault() without incident. However, when we are executing
no-fault sections of the kernel, we are not allowed to execute
vm_fault(). This change introduces special-case handling for spurious
page faults that occur in no-fault sections of the kernel.
In collaboration with: kib
Tested by: gibbs (an earlier version)
I would also like to acknowledge Hiroki Sato's assistance in
diagnosing this problem.
MFC after: 1 week
along with functions, SYSCTLs and tunables that are not used with
ATA_CAM in #ifndef ATA_CAM, similar to the existing #ifdef'ed ATA_CAM
code for the other way around. This makes it easier to understand
which parts of ata(4) actually are used in the new world order and
to later on remove the !ATA_CAM bits. It also makes it obvious that
there is something fishy with the C-bus front-end as well as in the
ATP850 support, as these used ATA_LOCKING which is defunct in the
ATA_CAM case. When fixing the former, ATA_LOCKING probably needs to
be brought back in some form or other.
Reviewed by: mav
MFC after: 1 week
inp_socket. To avoid panic, do not dereference inp_socket,
but obtain reuse port option from inp_flags2, like this
is done after next call to in_pcblookup_local() a few lines
down below.
Submitted by: rwatson
As of FreeBSD 8, this driver should not be used. Applications that use
posix_openpt(2) and openpty(3) use the pts(4) that is built into the
kernel unconditionally. If it turns out high profile depend on the
pty(4) module anyway, I'd rather get those fixed. So please report any
issues to me.
The pty(4) module is still available as a kernel module of course, so a
simple `kldload pty' can be used to run old-style pseudo-terminals.
longer serve any purpose. Prior to r157446, they served a purpose
because there was a fixed amount of kernel virtual address space
reserved for pv entries at boot time. However, since that change pv
entries are accessed through the direct map, and so there is no limit
imposed by a fixed amount of kernel virtual address space.
Fix a couple of nearby style issues.
Reviewed by: jhb, kib
MFC after: 1 week
AcpiEnterSleepState() executes (optional) _GTS method since ACPICA 20120215
(r231844). To evaluate the method, we need malloc(9), which may sleep.
Reported by: bschmidt
MFC after: 3 days
Enable using the statically embedded blob from the kernel, if present. The KLD
loaded DTB takes precedence, but they are both recognized and handled in the
same way.
Submitted by: Lukasz Wojcik
Obtained from: Semihalf
MFC after: 1 week
is queued to the hardware.
Because multiple concurrent paths can execute ath_start(), multiple
concurrent paths can push frames into the software/hardware TX queue
and since preemption/interrupting can occur, there's the possibility
that a gap in time will occur between allocating the sequence number
and queuing it to the hardware.
Because of this, it's possible that a thread will have allocated a
sequence number and then be preempted by another thread doing the same.
If the second thread sneaks the frame into the BAW, the (earlier) sequence
number of the first frame will be now outside the BAW and will result
in the frame being constantly re-added to the tail of the queue.
There it will live until the sequence numbers cycle around again.
This also creates a hole in the RX BAW tracking which can also cause
issues.
This patch delays the sequence number allocation to occur only just before
the frame is going to be added to the BAW. I've been wanting to do this
anyway as part of a general code tidyup but I've not gotten around to it.
This fixes the PR.
However, it still makes it quite difficult to try and ensure in-order
queuing and dequeuing of frames. Since multiple copies of ath_start()
can be run at the same time (eg one TXing process thread, one TX completion
task/one RX task) the driver may end up having frames dequeued and pushed
into the hardware slightly/occasionally out of order.
And, to make matters more annoying, net80211 may have the same behaviour -
in the non-aggregation case, the TX code allocates sequence numbers
before it's thrown to the driver. I'll open another PR to investigate
this and potentially introduce some kind of final-pass TX serialisation
before frames are thrown to the hardware. It's also very likely worthwhile
adding some debugging code into ath(4) and net80211 to catch when/if this
does occur.
PR: kern/166190
segments.h to a new x86 segments.h.
Add __packed attribute to some structs (just to be sure).
Also make it clear that i386 GDT and LDT entries are used in ia64 code.
than 4GB. Specifically, the inlined version of 'ptoa' of the the 'int'
count of pages overflowed on 64-bit platforms. While here, change
vm_object_madvise() to accept two vm_pindex_t parameters (start and end)
rather than a (start, count) tuple to match other VM APIs as suggested
by alc@.
scheme. The LDM is a logical volume manager for MS Windows NT and it
is also known as dynamic volumes. It supports about 2000 partitions
and also provides the capability for software RAID implementations.
This version implements only partitioning scheme capability and based
on the linux-ntfs project documentation and several publications across
the Web. NOTE: JBOD, RAID0 and RAID5 volumes aren't supported.
An access to the LDM metadata is read-only. When LDM is on the disk
partitioned with MBR we can also destroy metadata. For the GPT
partitioned disks destroy action is not supported.
Reviewed by: ivoras (previous version)
MFC after: 1 month
excluded from superpage promotions. At least one of the reason is
that pv_table is sized for non-fictitious pages only.
Consistently check for the page to be non-fictitious before accesing
superpage pv list.
Sponsored by: The FreeBSD Foundation
Reviewed by: alc
MFC after: 2 weeks
driver is running driver would have already completed flow control
configuration. This change removes unnecessary media changes in
controller reconfiguration cases such that it does not trigger link
reestablishment for configuration change requests like promiscuous
mode change.
Reported by: Many
Tested by: Mike Tancsa <mike <> sentex dot net>
MFC after: 1 week
inserted after the priority token thus cleaning up the output.
- Remove the needless double internal do_add_char function.
- Resolve a possible deadlock if interrupts are
disabled and getnanotime is called
Reviewed by: bde kmacy, avg, sbruno (various versions)
Approved by: cperciva
MFC after: 2 weeks
reg.h with stubs.
The tREGISTER macros are only made visible on i386. These macros are
deprecated and should not be available on amd64.
The i386 and amd64 versions of struct reg have been renamed to struct
__reg32 and struct __reg64. During compilation either __reg32 or __reg64
is defined as reg depending on the machine architecture. On amd64 the i386
struct is also available as struct reg32 which is used in COMPAT_FREEBSD32
code.
Most of compat/ia32/ia32_reg.h is now IA64 only.
Reviewed by: kib (previous version)
manipulation of the pvo_vlink and pvo_olink entries is already protected
by the table lock, so most remaining instances of the acquisition of the
page queues lock can likely be replaced with the table lock, or removed
if the table lock is already held.
Reviewed by: alc
rather than the header file. With this also move RT_MAXFIBS and
RT_NUMFIBS into the implemantion to avoid further usage in other
code. rt_numfibs is all that should be needed.
This allows users to change the number of FIBs from 1..RT_MAXFIBS(16)
dynamically using the tunable without the need to change the kernel
config for the maximum anymore. This means that thet multi-FIB
feature is now fully available with GENERIC kernels.
The kernel option ROUTETABLES can still be used to set the default
numbers of FIBs in absence of the tunable.
Ok.ed by: julian, hrs, melifaro
MFC after: 2 weeks
behaviour on error from write RPC back to behaviour of old nfs client.
When set to not zero, the pages for which write failed are kept dirty.
PR: kern/165927
Reviewed by: alc
MFC after: 2 weeks
if the filesystem performed short write and we are skipping the page
due to this.
Propogate write error from the pager back to the callers of
vm_pageout_flush(). Report the failure to write a page from the
requested range as the FALSE return value from vm_object_page_clean(),
and propagate it back to msync(2) to return EIO to usermode.
While there, convert the clearobjflags variable in the
vm_object_page_clean() and arguments of the helper functions to
boolean.
PR: kern/165927
Reviewed by: alc
MFC after: 2 weeks
field are synchronized, there is no need for pmap_protect() to acquire
the page queues lock unless it is going to access the pv lists.
Reviewed by: kib
These are needed for some particular port configurations where the default
speed isn't suitable for all link speed types. (Ie, changing 10/100/1000MBit
PLL rate requires a similar MII clock rate, rather than a fixed MII rate.)
This is:
* only currently implemented for the ar71xx;
* isn't used anywhere (yet), as the final interface for this hasn't yet
been determined.
* printf -> device_printf
* print the buffer pointer and sequence number for any buffer that wasn't
correctly tidied up before it was freed. This is to aid in some
current SMP TX debugging stalls.
PR: kern/166190
Remove FPU types from compat/ia32/ia32_reg.h that are no longer needed.
Create machine/npx.h on amd64 to allow compiling i386 code that uses
this header.
The original npx.h and fpu.h define struct envxmm differently. Both
definitions have been included in the new x86 header as struct __envxmm32
and struct __envxmm64. During compilation either __envxmm32 or __envxmm64
is defined as envxmm depending on machine architecture. On amd64 the i386
struct is also available as struct envxmm32.
Reviewed by: kib
- Merge r232744 changes to pc98.
(Allow a kernel to be built with 'nodevice atpic'.)
- Move ICU related defines from x86/isa/atpic.c to x86/isa/icu.h and
use them in x86/x86/intr_machdep.c.
Reviewed by: jhb
or look them up individually in pmap_remove() and apply the same logic
in the other ranged operation (pmap_protect). This speeds up make
installworld by a factor of 2 on powerpc64.
MFC after: 1 week
For example, some BIOS for AMD SB600 south bridge may map HPET MMIO base
address as a memory BAR for SMBus controller depending on a PM register
configuration. Before r231161 (and r232086, subsequent MFC to stable/9),
it was not fatal but hpet(4) just failed to attach. Since we probe and
attach HPET earlier than PCI devices now, it caused unfortunate hard lockup.
With this patch, it does not hang any more and HPET works at the same time.
Clean up some style nits while I am in the neighborhood.
PR: kern/165647
Reviewed by: jhb
MFC after: 3 days
Doomed vnode is hardly of any use here, besides all callers handle error
case. vfs_hash_get() does the same.
Don't mess with vnode holdcount, vget() takes care of it already.
Approved by: mdf (mentor)
to match reality: clang does _not_ disable SSE automatically when
-mno-mmx is used, you have to specify -mno-sse explicitly.
Note this was the case even before r232894, which only makes a change in
the 'positive' flag case; e.g. when you specify -msse, MMX gets enabled
too.
MFC after: 1 week
hardclock() tick should be run on every active CPU, or on only one.
On my tests, avoiding extra interrupts because of this on 8-CPU Core i7
system with HZ=10000 saves about 2% of performance. At this moment option
implemented only for global timers, as reprogramming per-CPU timers is
too expensive now to be compensated by this benefit, especially since we
still have to regularly run hardclock() on at least one active CPU to
update system uptime. For global timer it is quite trivial: timer runs
always, but we just skip IPIs to other CPUs when possible.
Option is enabled by default now, keeping previous behavior, as periodic
hardclock() calls are still used at least to implement setitimer(2) with
ITIMER_VIRTUAL and ITIMER_PROF arguments. But since default schedulers don't
depend on it since r232917, we are much more free to experiment with it.
MFC after: 1 month
with HZ rate through the sched_tick() calls from hardclock().
Potentially it can be used to improve precision, but now it is just minus
one more reason to call hardclock() for every HZ tick on every active CPU.
SCHED_4BSD never used sched_tick(), but keep it in place for now, as at
least SCHED_FBFS existing in patches out of the tree depends on it.
MFC after: 1 month
