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.
IBAT entry in early boot in order to prevent possible faults from races
between the instruction cache and the MMU.
PR: powerpc/148003
MFC after: 3 days
the kernel compiled with QUOTA option. ufs_accessx() upgrades the vdp
vnode lock from shared to exclusive to assign the dquot structure to
the vnode, and ufs_delete_denied() is called when tvp is locked. Since
upgrade drops shared lock when non-blocked upgrade failed, LOR is there.
Reported and tested by: Dmitry Pryanishnikov <lynx.ripe gmail com>
Tested by: pho
PR: kern/147890
MFC after: 1 week
core lower then set on other cores. Do not try to test P-states on attach
on SMP systems. It is hopeless now and will just pollute verbose logs.
If needed, check still can be forced via loader tunable.
* Add some per-device sysctl entries which record the watchdog state -
whether it is armed; whether the last reboot was due to the watchdog.
* Add a per-device sysctl debug flag to enable logging watchdog arming/
disarming.
Reviewed by: gonzo@
measured interval as upper bound. It should be more precise then just
assuming hz/2. For idle CPU it should be quite precise, for busy - not
worse then before.
external variables named "i". The "_" prefix is reserved for infrastructure
type code and is therefore not expected to be used by normal code likely to
call DPCPU_SUM(). [1]
- Change DPCPU_SUM to return the sum rather than calculate and assign it
internally. Usage is now: "sum = DPCPU_SUM(dpcpu_var, member_to_sum);" [2]
- Fix some style nits. [3]
Sponsored by: FreeBSD Foundation
Suggested by: bde [3], mdf [1], kib [1,2], pjd [1,3]
Reviewed by: kib
MFC after: 1 week (instead of r209119)
Although the Keywest registers have only 1 byte of content, they are
secretly 4-byte registers, which became apparent from them moving on the
big-endian Uninorth version of the controller.
On Apple systems at least, all the level interrupts are wired active low.
Before this change, our PIC programming only worked because Apple hardware
ignores the interrupt polarity bit on all interrupts except IRQ 0.
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)
New code that creates character devices shouldn't use device unit
numbers, but only si_drv[12] to hold pointer to per-device data. Make
this function more future proof by removing the unit number argument.
Discussed with: kib
