Commit Graph

10 Commits

Author SHA1 Message Date
Attilio Rao
245a253538 Add the cpuset_t conversion for mips. 2011-05-13 16:42:05 +00:00
Alexander Motin
a157e42516 Refactor timer management code with priority to one-shot operation mode.
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.
2010-09-13 07:25:35 +00:00
John Baldwin
d9d8d1449d Add a new ipi_cpu() function to the MI IPI API that can be used to send an
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
2010-08-06 15:36:59 +00:00
Alexander Motin
44d1534122 Update MIPS timer code (except RMI) to utilize new MI event timer
infrastructure.

Reviewed by:	neel
2010-07-23 07:46:55 +00:00
Randall Stewart
4542827d4d This pushes all of JC's patches that I have in place. I
am now able to run 32 cores ok.. but I still will hang
on buildworld with a NFS problem. I suspect I am missing
a patch for the netlogic rge driver.

JC check and see if I am missing anything except your
core-mask changes

Obtained from:	JC
2010-05-16 19:43:48 +00:00
Neel Natu
6575ad7619 Stash the context of the running thread at the time an IPI_STOP is received
in 'stoppcbs[]'. We use the 'stoppcbs[]' context to generate the backtrace
of such stopped threads.
2010-03-11 07:17:14 +00:00
Neel Natu
1d4fd9f5a8 SMP support for the mips port.
The platform that supports SMP currently is a SWARM with a dual-core Sibyte
processor. The kernel config file to use is SWARM_SMP.

Reviewed by: imp, rrs
2010-02-09 06:24:43 +00:00
Attilio Rao
dc6fbf6545 * Completely Remove the option STOP_NMI from the kernel. This option
has proven to have a good effect when entering KDB by using a NMI,
but it completely violates all the good rules about interrupts
disabled while holding a spinlock in other occasions.  This can be the
cause of deadlocks on events where a normal IPI_STOP is expected.
* Adds an new IPI called IPI_STOP_HARD on all the supported architectures.
This IPI is responsible for sending a stop message among CPUs using a
privileged channel when disponible. In other cases it just does match a
normal IPI_STOP.
Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64
architectures, while on the other has a normal IPI_STOP effect. It is
responsibility of maintainers to eventually implement an hard stop
when necessary and possible.
* Use the new IPI facility in order to implement a new userend SMP kernel
function called stop_cpus_hard(). That is specular to stop_cpu() but
it does use the privileged channel for the stopping facility.
* Let KDB use the newly introduced function stop_cpus_hard() and leave
stop_cpus() for all the other cases
* Disable interrupts on CPU0 when starting the process of APs suspension.
* Style cleanup and comments adding

This patch should fix the reboot/shutdown deadlocks many users are
constantly reporting on mailing lists.

Please don't forget to update your config file with the STOP_NMI
option removal

Reviewed by:	jhb
Tested by:	pho, bz, rink
Approved by:	re (kib)
2009-08-13 17:09:45 +00:00
Marius Strobl
6f04e7b9aa Remove ipi_all() and ipi_self() as the former hasn't been used at
all to date and the latter also is only used in ia64 and powerpc
code which no longer serves a real purpose after bring-up and just
can be removed as well. Note that architectures like sun4u also
provide no means of implementing IPI'ing a CPU itself natively
in the first place.

Suggested by:	jhb
Reviewed by:	arch, grehan, jhb
2008-09-28 18:34:14 +00:00
Warner Losh
45d426a34e FreeBSD/mips port. The FreeBSD/mips port targets mips32, mips64,
mips32r2 and mips64r2 (and close relatives) processors.  There
presently is support for ADMtek ADM5120, A mips 4Kc in a malta board,
the RB533 routerboard (based on IDT RC32434) and some preliminary
support for sibtye/broadcom designs.  Other hardware support will be
forthcomcing.

This port boots multiuser under gxemul emulating the malta board and
also bootstraps on the hardware whose support is forthcoming...

Oleksandr Tymoshenko, Wojciech Koszek, Warner Losh, Olivier Houchard,
Randall Stewert and others that have contributed to the mips2 and/or
mips2-jnpr perforce branches.  Juniper contirbuted a generic mips port
late in the life cycle of the misp2 branch.  Warner Losh merged the
mips2 and Juniper code bases, and others list above have worked for
the past several months to get to multiuser.

In addition, the mips2 work owe a debt to the trail blazing efforts of
the original mips branch in perforce done by Juli Mallett.
2008-04-13 07:27:37 +00:00