On some architectures UCHAR_MAX and USHRT_MAX had type unsigned int.
However, lacking integer suffixes for types smaller than int, their type
should correspond to that of an object of type unsigned char (or short)
when used in an expression with objects of type int. In that case unsigned
char (short) are promoted to int (i.e. signed) so the type of UCHAR_MAX and
USHRT_MAX should also be int.
Where MIN/MAX constants implicitly have the correct type the suffix has
been removed.
While here, correct some comments.
Reviewed by: bde
Approved by: kib (mentor)
for manipulating pcb_flags. These inline functions are very similar to
atomic_set_char(9) and atomic_clear_char(9) but without unnecessary LOCK
prefix for SMP. Add comments about the rationale[1]. Use these functions
wherever possible. Although there are some places where it is not strictly
necessary (e.g., a PCB is copied to create a new PCB), it is done across
the board for sake of consistency. Turn pcb_full_iret into a PCB flag as
it is safe now. Move rarely used fields before pcb_flags and reduce size
of pcb_flags to one byte. Fix some style(9) nits in pcb.h while I am in
the neighborhood.
Reviewed by: kib
Submitted by: kib[1]
MFC after: 2 months
the original amd64 and i386 headers with stubs.
Rename (AMD64|I386)_BUS_SPACE_* to X86_BUS_SPACE_* everywhere.
Reviewed by: imp (previous version), jhb
Approved by: kib (mentor)
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
functions, they are unused. Remove 'user' from npxgetuserregs()
etc. names.
For {npx,fpu}{get,set}regs(), always use pcb->pcb_user_save for FPU
context storage. This eliminates the need for ugly copying with
overwrite of the newly added and reserved fields in ucontext on i386
to satisfy alignment requirements for fpusave() and fpurstor().
pc98 version was copied from i386.
Suggested and reviewed by: bde
Tested by: pho (i386 and amd64)
MFC after: 1 week
These MSRs can be used to determine actual (average) performance as
compared to a maximum defined performance.
Availability of these MSRs is indicated by bit0 in CPUID.6.ECX on both
Intel and AMD processors.
MFC after: 5 days
It seems that this MSR has been available in a range of AMD processors
families for quite a while now.
Note1: not all AMD MSRs that are found in amd64 specialreg.h are also in
the i386 version.
Note2: perhaps some additional name component is needed to distinguish
AMD-specific MSRs.
MFC after: 5 days
After KVA space was increased to 512GB on amd64 it became impractical
to use PTEs as entries in the minidump map of dumped pages, because size
of that map alone would already be 1GB.
Instead, we now use PDEs as page map entries and employ two stage lookup
in libkvm: virtual address -> PDE -> PTE -> physical address. PTEs are
now dumped as regular pages. Fixed page map size now is 2MB.
libkvm keeps support for accessing amd64 minidumps of version 1.
Support for 1GB pages is added.
Many thanks to Alan Cox for his guidance, numerous reviews, suggestions,
enhancments and corrections.
Reviewed by: alc [kernel part]
MFC after: 15 days
contents of the ones that were not empty were stale and unused.
- Now that <machine/mutex.h> no longer exists, there is no need to allow it
to override various helper macros in <sys/mutex.h>.
- Rename various helper macros for low-level operations on mutexes to live
in the _mtx_* or __mtx_* namespaces. While here, change the names to more
closely match the real API functions they are backing.
- Drop support for including <sys/mutex.h> in assembly source files.
Suggested by: bde (1, 2)
physical page mapping should span two or more MTRRs of different types.
Add a pmap function, pmap_demote_DMAP(), by which the MTRR module can
ensure that the direct map region doesn't have such a mapping.
[2] Fix a couple of nearby style errors in amd64_mrset().
[3] Re-enable the use of 1GB page mappings for implementing the direct
map. (See also r197580 and r213897.)
Tested by: kib@ on a Westmere-family processor [3]
MFC after: 3 weeks
KVA space is abundant on amd64, so there is no reason to limit kernel
map size to a fraction of available physical memory. In fact, it could
be larger than physical memory.
This should help with memory auto-tuning for ZFS and shouldn't affect
other workloads.
This should reduce number of circumstances for "kmem_map too small"
panics, but probably won't eliminate them entirely due to potential kmem
fragmentation.
In fact, you might want/need to limit maximum ARC size after this commit
if you need to resrve more memory for applications.
This change was discussed on arch@ and nobody said "don't do it".
MFC after: 6 weeks
The main goal of this is to generate timer interrupts only when there is
some work to do. When CPU is busy interrupts are generating at full rate
of hz + stathz to fullfill scheduler and timekeeping requirements. But
when CPU is idle, only minimum set of interrupts (down to 8 interrupts per
second per CPU now), needed to handle scheduled callouts is executed.
This allows significantly increase idle CPU sleep time, increasing effect
of static power-saving technologies. Also it should reduce host CPU load
on virtualized systems, when guest system is idle.
There is set of tunables, also available as writable sysctls, allowing to
control wanted event timer subsystem behavior:
kern.eventtimer.timer - allows to choose event timer hardware to use.
On x86 there is up to 4 different kinds of timers. Depending on whether
chosen timer is per-CPU, behavior of other options slightly differs.
kern.eventtimer.periodic - allows to choose periodic and one-shot
operation mode. In periodic mode, current timer hardware taken as the only
source of time for time events. This mode is quite alike to previous kernel
behavior. One-shot mode instead uses currently selected time counter
hardware to schedule all needed events one by one and program timer to
generate interrupt exactly in specified time. Default value depends of
chosen timer capabilities, but one-shot mode is preferred, until other is
forced by user or hardware.
kern.eventtimer.singlemul - in periodic mode specifies how much times
higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 2 and 4, but could be reduced to 1
if extra interrupts are unwanted.
kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
independently of whether they busy or not. By default this options is
disabled. If chosen timer is per-CPU and runs in periodic mode, this option
has no effect - all interrupts are generating.
As soon as this patch modifies cpu_idle() on some platforms, I have also
refactored one on x86. Now it makes use of MONITOR/MWAIT instrunctions
(if supported) under high sleep/wakeup rate, as fast alternative to other
methods. It allows SMP scheduler to wake up sleeping CPUs much faster
without using IPI, significantly increasing performance on some highly
task-switching loads.
Tested by: many (on i386, amd64, sparc64 and powerc)
H/W donated by: Gheorghe Ardelean
Sponsored by: iXsystems, Inc.
In particular, provide pagesize and pagesizes array, the canary value
for SSP use, number of host CPUs and osreldate.
Tested by: marius (sparc64)
MFC after: 1 month
IPI to a specific CPU by its cpuid. Replace calls to ipi_selected() that
constructed a mask for a single CPU with calls to ipi_cpu() instead. This
will matter more in the future when we transition from cpumask_t to
cpuset_t for CPU masks in which case building a CPU mask is more expensive.
Submitted by: peter, sbruno
Reviewed by: rookie
Obtained from: Yahoo! (x86)
MFC after: 1 month
savectx() is only used for panic dump (dumppcb) and kdb (stoppcbs). Thus,
saving additional information does not hurt and it may be even beneficial.
Unfortunately, struct pcb has grown larger to accommodate more data.
Move 512-byte long pcb_user_save to the end of struct pcb while I am here.
- savectx() now saves FPU state unconditionally and copy it to the PCB of
FPU thread if necessary. This gives panic dump and kdb a chance to take
a look at the current FPU state even if the FPU is "supposedly" not used.
- Resuming CPU now unconditionally reinitializes FPU. If the saved FPU
state was irrelevant, it could be in an unknown state.
Suggested by: bde [1]
Xeon 5500/5600 series:
- Utilize IA32_TEMPERATURE_TARGET, a.k.a. Tj(target) in place
of Tj(max) when a sane value is available, as documented
in Intel whitepaper "CPU Monitoring With DTS/PECI"; (By sane
value we mean 70C - 100C for now);
- Print the probe results when booting verbose;
- Replace cpu_mask with cpu_stepping;
- Use CPUID_* macros instead of rolling our own.
Approved by: rpaulo
MFC after: 1 month
from the inline assembly. This allows the compiler to cache invocations of
curthread since it's value does not change within a thread context.
Submitted by: zec (i386)
MFC after: 1 week
now it uses a very dumb first-touch allocation policy. This will change in
the future.
- Each architecture indicates the maximum number of supported memory domains
via a new VM_NDOMAIN parameter in <machine/vmparam.h>.
- Each cpu now has a PCPU_GET(domain) member to indicate the memory domain
a CPU belongs to. Domain values are dense and numbered from 0.
- When a platform supports multiple domains, the default freelist
(VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain.
The MD code is required to populate an array of mem_affinity structures.
Each entry in the array defines a range of memory (start and end) and a
domain for the range. Multiple entries may be present for a single
domain. The list is terminated by an entry where all fields are zero.
This array of structures is used to split up phys_avail[] regions that
fall in VM_FREELIST_DEFAULT into per-domain freelists.
- Each memory domain has a separate lookup-array of freelists that is
used when fulfulling a physical memory allocation. Right now the
per-domain freelists are listed in a round-robin order for each domain.
In the future a table such as the ACPI SLIT table may be used to order
the per-domain lookup lists based on the penalty for each memory domain
relative to a specific domain. The lookup lists may be examined via a
new vm.phys.lookup_lists sysctl.
- The first-touch policy is implemented by using PCPU_GET(domain) to
pick a lookup list when allocating memory.
Reviewed by: alc
name of 32bit sibling architecture instead of the host one. Do the
same for hw.machine on amd64.
Add a safety belt debug.adaptive_machine_arch sysctl, to turn the
substitution off.
Reviewed by: jhb, nwhitehorn
MFC after: 2 weeks
- change the type of pm_active to cpumask_t, which it is;
- in pmap_remove_pages(), compare with PCPU(curpmap), instead of
dereferencing the long chain of pointers [1].
For amd64 pmap, remove the unneeded checks for validity of curpmap
in pmap_activate(), since curpmap should be always valid after
r209789.
Submitted by: alc [1]
Reviewed by: alc
MFC after: 3 weeks
ABI specifies the DF should be zero, and newer compilers do not clear
DF before using DF-sensitive instructions.
The DF clearing for signal handlers was done some time ago.
MFC after: 1 week
writing event timer drivers, for choosing best possible drivers by machine
independent code and for operating them to supply kernel with hardclock(),
statclock() and profclock() events in unified fashion on various hardware.
Infrastructure provides support for both per-CPU (independent for every CPU
core) and global timers in periodic and one-shot modes. MI management code
at this moment uses only periodic mode, but one-shot mode use planned for
later, as part of tickless kernel project.
For this moment infrastructure used on i386 and amd64 architectures. Other
archs are welcome to follow, while their current operation should not be
affected.
This patch updates existing drivers (i8254, RTC and LAPIC) for the new
order, and adds event timers support into the HPET driver. These drivers
have different capabilities:
LAPIC - per-CPU timer, supports periodic and one-shot operation, may
freeze in C3 state, calibrated on first use, so may be not exactly precise.
HPET - depending on hardware can work as per-CPU or global, supports
periodic and one-shot operation, usually provides several event timers.
i8254 - global, limited to periodic mode, because same hardware used also
as time counter.
RTC - global, supports only periodic mode, set of frequencies in Hz
limited by powers of 2.
Depending on hardware capabilities, drivers preferred in following orders,
either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC.
User may explicitly specify wanted timers via loader tunables or sysctls:
kern.eventtimer.timer1 and kern.eventtimer.timer2.
If requested driver is unavailable or unoperational, system will try to
replace it. If no more timers available or "NONE" specified for second,
system will operate using only one timer, multiplying it's frequency by few
times and uing respective dividers to honor hz, stathz and profhz values,
set during initial setup.
This information can be very valuable for CPU sleep-time (and respectively
idle power consumption) optimization.
Add counters for timer-related IPIs.
Reviewed by: jhb@ (previous version)
FPU/SSE hardware. Caller should provide a save area that is chained
into the stack of the areas; pcb save_area for usermode FPU state is
on top. The pcb now contains a pointer to the current FPU saved area,
used during FPUDNA handling and context switches. There is also a
facility to allow the kernel thread to use pcb save_area.
Change the dreaded warnings "npxdna in kernel mode!" into the panics
when FPU usage is not registered.
KPI discussed with: fabient
Tested by: pho, fabient
Hardware provided by: Sentex Communications
MFC after: 1 month
