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.
Bring in a driver for the LSI Logic MPT2 6Gb SAS controllers.
This driver supports basic I/O, and works with SAS and SATA drives and
expanders.
Basic error recovery works (i.e. timeouts and aborts) as well.
Integrated RAID isn't supported yet, and there are some known bugs.
So this isn't ready for production use, but is certainly ready for
testing and additional development. For the moment, new commits to this
driver should go into the FreeBSD Perforce repository first
(//depot/projects/mps/...) and then get merged into -current once
they've been vetted.
This has only been added to the amd64 GENERIC, since that is the only
architecture I have tested this driver with.
Submitted by: scottl
Discussed with: imp, gibbs, will
Sponsored by: Yahoo, Spectra Logic Corporation
This reflects actual type used to store and compare child device orders.
Change is mostly done via a Coccinelle (soon to be devel/coccinelle)
semantic patch.
Verified by LINT+modules kernel builds.
Followup to: r212213
MFC after: 10 days
malo and mwl use the firmware framework to access firmware images.
Depending on the firmware modules itself is not required and in this
case even wrong because no modules with those names exist.
Pointed out by: brucec
MFC after: 1 week
handlers, some of which had to do awkward things to get a large enough
FIXEDLEN buffer.
Note that some sysctl handlers were explicitly outputting a trailing NUL
byte. This behaviour was preserved, though it should not be necessary.
Reviewed by: phk
PCI status register to map its current name.
- Use PCIM_* rather than PCIR_* for constants for fields in various AER
registers. I got about half of them right in the previous commit.
MFC after: 1 week
K2 SATA controllers. The chip's status register must be read first, and
as a long, for other registers to be correctly updated after a command, and
this includes the command sequence in device detection as well as the
previously handled case after interrupts. While here, clean up some
previous hacks related to this controller.
Reported by: many
Reviewed by: mav
MFC after: 3 weeks
PCI-express. I used PCIZ_* for ID constants (plain capability IDs use
PCIY_*).
- Add register definitions for the Advanced Error Reporting, Virtual
Channels, and Device Serial Number extended capabilities.
- Teach pciconf -c to list extended as well as plain capabilities. Adds
more detailed parsing for AER, VC, and device serial numbers.
MFC after: 2 weeks
are still bound to BSP. It confuses timer management logic in per-CPU mode
and may cause timer not being reloaded. Check such cases on interrupt
arival and reload timer to give system some more time to manage proper
binding.
discrepencies from the igb version which was the target.
Change the message when neither MSI or MSIX are enabled
and a fallback to Legacy interrupts happen, the existing
message was confusing.
- add identify method to create driver's own device_t
- successfully probe only driver's own device_t instead of any device_t
- (ab)use device order to hopefully be probed/attached after acpi_wmi
PR: kern/147858
Tested by: Maciej Suszko <maciej@suszko.eu>
MFC after: 1 week
- Add special check for case when time expires before being programmed.
This fixes interrupt loss and respectively timer death on attempt to
program very short interval. Increase minimal supported period to more
realistic value.
- Add support for hint.hpet.X.allowed_irqs tunable, allowing manually
specify which interrupts driver allowed to use. Unluckily, many BIOSes
program wrong allowed interrupts mask, so driver tries to stay on safe
side by not using unshareable ISA IRQs. This option gives control over
this limitation, allowing more per-CPU timers to be provided, when FSB
interrupts are not supported. Value of this tunable is bitmask.
- Do not use regular interrupts on virtual machines. QEMU and VirtualBox
do not support them properly, that may cause problems. Stay safe by default.
Same time both QEMU and VirtualBox work fine in legacy_route mode.
VirtualBox also works fine if manually specify allowed ISA IRQs with above.
Both deadline and current_time are time_seconds (+ utc_offset())
casted to unsigned long long. No need to cast to or print as pointers.
MFC after: 4 days
to pad with 0xFF when it encounter short frames. According to RFC
1042 the pad bytes should be 0x00.
Because manual padding consumes extra CPU cycles, introduce a new
tunable which controls the padding behavior. Turning this tunable
on will have driver pad manually but it's disabled by default. Users
can enable software padding by setting the following tunable to
non-zero value.
dev.sis.%d.manual_pad="1"
PR: kern/35422 (patch not used)
prevented driver from working on big-endian machines. Also rewrite
station address programming to make it work on strict-alignment
architectures. With this change, sis(4) now works on sparc64 and
performance number looks good even though sis(4) have to apply
fixup code to align received frames on 2 bytes boundary on sparc64.
response to DMA activate FIS under certain circumstances. This is
recommended fix from chip datasheet. If triggered, this bug most likely
cause write command timeout.
MFC after: 2 weeks
value 0xff. On hot-plug this value confuses ata_generic_reset() device
presence detection logic. As soon as we already know drive presence from
SATA hard reset, hint ata_generic_reset() to wait for device signature
until success or full timeout.
greater than 65535 bytes then the CDC driver might not work as expected, which
is not likely with the existing USB speeds.
Submitted by: Hans Petter Selasky
