Commit Graph

253 Commits

Author SHA1 Message Date
Konstantin Belousov
e637a6e3f9 The smp_rendezvous_cpus() function should ensure that all accesses
done by the functions called on other CPUs, are visible to the caller.
Pair otherwise useless acquire on smp_rv_waiters[3] with a release add
to ensure synchronized with relation, which guarantees visibility.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2015-07-21 22:56:46 +00:00
Hans Petter Selasky
af3b2549c4 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
Glen Barber
37a107a407 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
Hans Petter Selasky
3da1cf1e88 Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
Scott Long
60ad8150c7 Retire smp_active. It was racey and caused demonstrated problems with
the cpufreq code.  Replace its use with smp_started.  There's at least
one userland tool that still looks at the kern.smp.active sysctl, so
preserve it but point it to smp_started as well.

Discussed with: peter, jhb
MFC after: 3 days
Obtained from: Netflix
2014-04-26 20:27:54 +00:00
John Baldwin
e432d5f6a7 Drop the 3rd clause from all 3 clause BSD licenses where I am the sole
holder to convert them to 2 clause BSD licenses.

MFC after:	1 week
2014-02-05 18:13:27 +00:00
Justin T. Gibbs
255424ddb7 Fix ia64 and mips kernel builds due to XENHVM=>GENERIC integration in
revision 255744.

sys/kern/subr_smp.c:
	IPI_SUSPEND is only available on amd64 and i386.  Protect
	new uses of this constant with #ifdefs to avoid impacting
	other platforms.

Approved by:	re (blanket Xen)
2013-09-22 02:46:13 +00:00
Justin T. Gibbs
566a5f5020 Merge Xen PVHVM support into the GENERIC kernel config for both
amd64 and i386.

Submitted by:	Roger Pau Monné
Sponsored by:	Citrix Systems R&D
Reviewed by:	gibbs
Approved by:	re (blanket Xen)
MFC after:	2 weeks

sys/amd64/amd64/mp_machdep.c:
sys/amd64/include/cpu.h:
sys/i386/i386/mp_machdep.c:
sys/i386/include/cpu.h:
	- Introduce two new CPU hooks for initialization and resume
	  purposes. This allows us to get rid of the XENHVM ifdefs in
	  mp_machdep, and also sets some hooks into common code that can be
	  used by other hypervisor implementations.

sys/amd64/conf/XENHVM:
sys/i386/conf/XENHVM:
	- Remove these configs now that GENERIC has builtin support for Xen
	  HVM.

sys/kern/subr_smp.c:
	- Make sure there are no pending IPIs when suspending a system.

sys/x86/xen/hvm.c:
	- Add cpu init and resume vectors that are called from mp_machdep
	  using the new hooks.
	- Only clear the vcpu_info mapping data on resume.  It is already
	  clear for the BSP on a cold boot and is set correctly as APs
	  are started.
	- Gate xen_hvm_init_cpu only to systems running under Xen.

sys/x86/xen/xen_intr.c:
	 - Gate the setup of event channels only to systems running under Xen.
2013-09-20 22:59:22 +00:00
Justin T. Gibbs
428b7ca290 Add support for suspend/resume/migration operations when running as a
Xen PVHVM guest.

Submitted by:	Roger Pau Monné
Sponsored by:	Citrix Systems R&D
Reviewed by:	gibbs
Approved by:	re (blanket Xen)
MFC after:	2 weeks

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
	- Make sure that are no MMU related IPIs pending on migration.
	- Reset pending IPI_BITMAP on resume.
	- Init vcpu_info on resume.

sys/amd64/include/intr_machdep.h:
sys/i386/include/intr_machdep.h:
sys/x86/acpica/acpi_wakeup.c:
sys/x86/x86/intr_machdep.c:
sys/x86/isa/atpic.c:
sys/x86/x86/io_apic.c:
sys/x86/x86/local_apic.c:
	- Add a "suspend_cancelled" parameter to pic_resume().  For the
	  Xen PIC, restoration of interrupt services differs between
	  the aborted suspend and normal resume cases, so we must provide
	  this information.

sys/dev/acpica/acpi_timer.c:
sys/dev/xen/timer/timer.c:
sys/timetc.h:
	- Don't swap out "suspend safe" timers across a suspend/resume
	  cycle.  This includes the Xen PV and ACPI timers.

sys/dev/xen/control/control.c:
	- Perform proper suspend/resume process for PVHVM:
		- Suspend all APs before going into suspension, this allows us
		  to reset the vcpu_info on resume for each AP.
		- Reset shared info page and callback on resume.

sys/dev/xen/timer/timer.c:
	- Implement suspend/resume support for the PV timer. Since FreeBSD
	  doesn't perform a per-cpu resume of the timer, we need to call
	  smp_rendezvous in order to correctly resume the timer on each CPU.

sys/dev/xen/xenpci/xenpci.c:
	- Don't reset the PCI interrupt on each suspend/resume.

sys/kern/subr_smp.c:
	- When suspending a PVHVM domain make sure there are no MMU IPIs
	  in-flight, or we will get a lockup on resume due to the fact that
	  pending event channels are not carried over on migration.
	- Implement a generic version of restart_cpus that can be used by
	  suspended and stopped cpus.

sys/x86/xen/hvm.c:
	- Implement resume support for the hypercall page and shared info.
	- Clear vcpu_info so it can be reset by APs when resuming from
	  suspension.

sys/dev/xen/xenpci/xenpci.c:
sys/x86/xen/hvm.c:
sys/x86/xen/xen_intr.c:
	- Support UP kernel configurations.

sys/x86/xen/xen_intr.c:
	- Properly rebind per-cpus VIRQs and IPIs on resume.
2013-09-20 05:06:03 +00:00
Jeff Roberson
5b39d5c739 - Correctly handle EWOULDBLOCK in quiesce_cpus
Discussed with:	mav
2012-12-19 20:08:06 +00:00
Jeff Roberson
28d91af30f - Implement run-time expansion of the KTR buffer via sysctl.
- Implement a function to ensure that all preempted threads have switched
   back out at least once.  Use this to make sure there are no stale
   references to the old ktr_buf or the lock profiling buffers before
   updating them.

Reviewed by:	marius (sparc64 parts), attilio (earlier patch)
Sponsored by:	EMC / Isilon Storage Division
2012-11-15 00:51:57 +00:00
Mitsuru IWASAKI
c1b0dc80b5 Another fixe for r236772.
- Adjust correct cpuset (stopped_cpus/suspended_cpus) for
  cpu_spinwait() in generic_stop_cpus().
2012-06-11 18:47:26 +00:00
Mitsuru IWASAKI
fb864578af Add x86/acpica/acpi_wakeup.c for amd64 and i386. Difference of
suspend/resume procedures are minimized among them.

common:
- Add global cpuset suspended_cpus to indicate APs are suspended/resumed.
- Remove acpi_waketag and acpi_wakemap from acpivar.h (no longer used).
- Add some variables in acpi_wakecode.S in order to minimize the difference
  among amd64 and i386.
- Disable load_cr3() because now CR3 is restored in resumectx().

amd64:
- Add suspend/resume related members (such as MSR) in PCB.
- Modify savectx() for above new PCB members.
- Merge acpi_switch.S into cpu_switch.S as resumectx().

i386:
- Merge(and remove) suspendctx() into savectx() in order to match with
  amd64 code.

Reviewed by:	attilio@, acpi@
2012-06-09 00:37:26 +00:00
Mitsuru IWASAKI
e3fd0bc1b2 Add SMP/i386 suspend/resume support.
Most part is merged from amd64.

- i386/acpica/acpi_wakecode.S
Replaced with amd64 code (from realmode to paging enabling code).

- i386/acpica/acpi_wakeup.c
Replaced with amd64 code (except for wakeup_pagetables stuff).

- i386/include/pcb.h
- i386/i386/genassym.c
Added PCB new members (CR0, CR2, CR4, DS, ED, FS, SS, GDT, IDT, LDT
and TR) needed for suspend/resume, not for context switch.

- i386/i386/swtch.s
Added suspendctx() and resumectx().
Note that savectx() was not changed and used for suspending (while
amd64 code uses it).
BSP and AP execute the same sequence, suspendctx(), acpi_wakecode()
and resumectx() for suspend/resume (in case of UP system also).

- i386/i386/apic_vector.s
Added cpususpend().

- i386/i386/mp_machdep.c
- i386/include/smp.h
Added cpususpend_handler().

- i386/include/apicvar.h
- kern/subr_smp.c
- sys/smp.h
Added IPI_SUSPEND and suspend_cpus().

- i386/i386/initcpu.c
- i386/i386/machdep.c
- i386/include/md_var.h
- pc98/pc98/machdep.c
Moved initializecpu() declarations to md_var.h.

MFC after:	3 days
2012-05-18 18:55:58 +00:00
Ed Schouten
6472ac3d8a Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
Attilio Rao
2b10b1f872 Disable interrupt and preemption for smp_rendezvous() also in the
UP/!SMP case.
The callbacks may be relying on this feature and having 2 different
ways to deal with them is not correct.

Reported by:	rstone
Reviewed by:	jhb
MFC after:	2 weeks
2011-11-03 14:36:56 +00:00
Andriy Gapon
35edc49853 smp_rendezvous: master cpu should wait until all slaves are fully done
This is a followup to r222032 and a reimplementation of it.
While that revision fixed the race for the smp_rv_waiters[2] exit
sentinel, it still left a possibility for a target CPU to access
stale or wrong smp_rv_func_arg in smp_rv_teardown_func.
To fix this race the slave CPUs signal when they are really fully
done with the rendezvous and the master CPU waits until all slaves
are done.

Diagnosed by:	kib
Reviewed by:	jhb, mlaier, neel
Approved by:	re (kib)
MFC after:	2 weeks
2011-07-30 20:29:39 +00:00
Robert Watson
ff66f6a404 Define two new sysctl node flags: CTLFLAG_CAPRD and CTLFLAG_CAPRW, which
may be jointly referenced via the mask CTLFLAG_CAPRW.  Sysctls with these
flags are available in Capsicum's capability mode; other sysctl nodes are
not.

Flag several useful sysctls as available in capability mode, such as memory
layout sysctls required by the run-time linker and malloc(3).  Also expose
access to randomness and available kernel features.

A few sysctls are enabled to support name->MIB conversion; these may leak
information to capability mode by virtue of providing resolution on names
not flagged for access in capability mode.  This is, generally, not a huge
problem, but might be something to resolve in the future.  Flag these cases
with XXX comments.

Submitted by:	jonathan
Sponsored by:	Google, Inc.
2011-07-17 23:05:24 +00:00
Attilio Rao
cfdfd32d34 MFC 2011-06-26 17:30:46 +00:00
Andriy Gapon
1aac6ac94a generic_stop_cpus: pull timeout logic from under DIAGNOSTIC
... and also increase the timeout.
It's better to try to proceed somehow despite stuck CPUs than to hang
indefinitely.  Especially so during shutdown and when entering kdb or panic.

Timeout value is still an aribitrary value.
Timeout diagnostic is just a printf; the work on something more
debuggable is planned by attilio.  Need to be careful here as
stop_cpus_hard is called very early while enetering kdb and soon(-ish)
it may become called very early when entering panic.

Reviewed by:	attilio
MFC after:	2 months
2011-06-25 10:01:43 +00:00
Attilio Rao
a38f1f263b Remove pc_cpumask and pc_other_cpus usage from MI code.
Tested by:	pluknet
2011-06-13 13:28:31 +00:00
Attilio Rao
7fcdc9a26f MFC 2011-05-26 17:38:00 +00:00
John Baldwin
5b41f90fd1 Silly spelling typos.
Submitted by:	"b. f."
2011-05-24 19:55:57 +00:00
John Baldwin
47ad691f87 Fix an issue with critical sections and SMP rendezvous handlers.
Specifically, a critical_exit() call that drops the nesting level to zero
has a brief window where the pending preemption flag is set and the
nesting level is set to zero.  This is done purposefully to avoid races
where a preemption scheduled by an interrupt could be lost otherwise (see
revision 144777).  However, this does mean that if an interrupt fires
during this window and enters and exits a critical section, it may preempt
from the interrupt context.  This is generally fine as the interrupt code
is careful to arrange critical sections so that they are not exited until
it is safe to preempt (e.g. interrupts EOI'd and masked if necessary).

However, the SMP rendezvous IPI handler does not quite follow this rule,
and in general a rendezvous can never be preempted.  Rendezvous handlers
are also not permitted to schedule threads to execute, so they will not
typically trigger preemptions.  SMP rendezvous handlers may use
spinlocks (carefully) such as the rm_cleanIPI() handler used in rmlocks,
but using a spinlock also enters and exits a critical section.  If the
interrupted top-half code is in the brief window of critical_exit() where
the nesting level is zero but a preemption is pending, then releasing the
spinlock can trigger a preemption.  Because we know that SMP rendezvous
handlers can never schedule a thread, we know that a critical_exit() in
an SMP rendezvous handler will only preempt in this edge case.  We also
know that the top-half thread will happily handle the deferred preemption
once the SMP rendezvous has completed, so the preemption will not be lost.

This makes it safe to employ a workaround where we use a nested critical
section in the SMP rendezvous code itself around rendezvous action
routines to prevent any preemptions during an SMP rendezvous.  The
workaround intentionally avoids checking for a deferred preemption
when leaving the critical section on the assumption that if there is a
pending preemption it will be handled by the interrupted top-half code.

Submitted by:	mlaier (variation specific to rm_cleanIPI())
Obtained from:	Isilon
MFC after:	1 week
2011-05-24 13:36:41 +00:00
Attilio Rao
a8586beeb0 Fix mismerge.
Reported by:	pluknet
2011-05-18 15:50:12 +00:00
Attilio Rao
fea3a3fa94 MFC 2011-05-17 22:03:01 +00:00
John Baldwin
f83e8b25c1 Fix a race in the SMP rendezvous code. Specifically, the write by the
last CPU to to finish the rendezvous action may become visible to
different CPUs at different times.  As a result, the CPU that initiated
the rendezvous may exit the rendezvous and drop the lock allowing another
rendezvous to be initiated on the same CPU or a different CPU.  In that
case the exit sentinel may be cleared before all CPUs have noticed causing
those CPUs to hang forever.

Workaround this by using a generation count to notice when this race
occurs and to exit the rendezvous in that case.

The problem was independently diagnosted by mlaier@ and avg@ as well.

Submitted by:	neel
Reviewed by:	avg, mlaier
Obtained from:	NetApp
MFC after:	1 week
2011-05-17 16:39:08 +00:00
Attilio Rao
d59dd76c22 Merge r221278 from largeSMP project:
idle_cpus_mask is just used in sched_4bsd, thus make it private for it.

Tested by:	several
2011-05-16 23:20:12 +00:00
Attilio Rao
71a19bdc64 Commit the support for removing cpumask_t and replacing it directly with
cpuset_t objects.
That is going to offer the underlying support for a simple bump of
MAXCPU and then support for number of cpus > 32 (as it is today).

Right now, cpumask_t is an int, 32 bits on all our supported architecture.
cpumask_t on the other side is implemented as an array of longs, and
easilly extendible by definition.

The architectures touched by this commit are the following:
- amd64
- i386
- pc98
- arm
- ia64
- XEN

while the others are still missing.
Userland is believed to be fully converted with the changes contained
here.

Some technical notes:
- This commit may be considered an ABI nop for all the architectures
  different from amd64 and ia64 (and sparc64 in the future)
- per-cpu members, which are now converted to cpuset_t, needs to be
  accessed avoiding migration, because the size of cpuset_t should be
  considered unknown
- size of cpuset_t objects is different from kernel and userland (this is
  primirally done in order to leave some more space in userland to cope
  with KBI extensions). If you need to access kernel cpuset_t from the
  userland please refer to example in this patch on how to do that
  correctly (kgdb may be a good source, for example).
- Support for other architectures is going to be added soon
- Only MAXCPU for amd64 is bumped now

The patch has been tested by sbruno and Nicholas Esborn on opteron
4 x 12 pack CPUs. More testing on big SMP is expected to came soon.
pluknet tested the patch with his 8-ways on both amd64 and i386.

Tested by:	pluknet, sbruno, gianni, Nicholas Esborn
Reviewed by:	jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
Attilio Rao
3121f5347e idle_cpus_mask is just used in the SMP case and within sched_4BSD.
Declare appropriately.
2011-04-30 22:30:18 +00:00
Juli Mallett
37142d9e87 With smp_topo_none, set cg_mask to all_cpus rather than setting the mp_ncpus
low bits.

Submitted by:	Bhanu Prakash
Reviewed by:	jeffr
2011-02-11 22:43:10 +00:00
Matthew D Fleming
fbbb13f962 sysctl(9) cleanup checkpoint: amd64 GENERIC builds cleanly.
Commit the kernel changes.
2011-01-12 19:54:19 +00:00
Andriy Gapon
9ddb6637b8 generic_stop_cpus: prevent parallel execution
This is based on the same approach as used in panic().
In theory parallel execution of generic_stop_cpus()  could lead to two CPUs
stopping each other and everyone else, and thus a total system halt.
Also, in theory, we should have some smarter locking here, because two
(or more CPUs) could be stopping unrelated sets of CPUs.
But in practice, it seems, this function is only used to stop
"all other" CPUs.

Additionally, I took this opportunity to make amd64-specific suspend_cpus()
function use generic_stop_cpus() instead of rolling out essentially
duplicate code.

This code is based on code by Sandvine Incorporated.

Suggested by:	mdf
Reviewed by:	jhb, jkim (earlier version)
MFC after:	2 weeks
2010-10-12 17:40:45 +00:00
Attilio Rao
2d8b420b9f The r208165 fixed a bug related to unsigned integer overflowing for the
number of CPUs detection.
However, that was not mention at all, the problem was not reported, the
patch has not been MFCed and the fix is mostly improper.

Fix the original overflow (caused when 32 CPUs must be detected) by
just using a different mathematical computation (it also makes more
explicit the size of operands involved, which is good in the moment
waiting for a more complete support for a large number of CPUs).

PR:		kern/148698
Submitted by:	Joe Landers <jlanders at vmware dot com>
Tested by:	gianni
MFC after:	10 days
2010-08-09 00:23:57 +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
John Baldwin
3aa6d94e0c Update several places that iterate over CPUs to use CPU_FOREACH(). 2010-06-11 18:46:34 +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
Attilio Rao
de6648745c Fix a hang introduced in r206878 for kernel compiled with SMP support but
being not actual SMP and similar situations by always initializing the
smp ipi mutex.

Reported by:	marius
MFC after:	3 days
X-MFC:		r206878
2010-05-11 15:36:16 +00:00
Konstantin Belousov
51a6ef34fb Remove forward_roundrobin(), it is unused for quite some time.
Reviewed by:	jhb
MFC after:	1 week
2009-09-21 13:09:56 +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
Jeff Roberson
7b55ab0534 - Remove the bogus idle thread state code. This may have a race in it
and it only optimized out an ipi or mwait in very few cases.
 - Skip the adaptive idle code when running on SMT or HTT cores.  This
   just wastes cpu time that could be used on a busy thread on the same
   core.
 - Rename CG_FLAG_THREAD to CG_FLAG_SMT to be more descriptive.  Re-use
   CG_FLAG_THREAD to mean SMT or HTT.

Sponsored by:   Nokia
2009-04-29 03:15:43 +00:00
Jung-uk Kim
c66d2b38c8 Initial suspend/resume support for amd64.
This code is heavily inspired by Takanori Watanabe's experimental SMP patch
for i386 and large portion was shamelessly cut and pasted from Peter Wemm's
AP boot code.
2009-03-17 00:48:11 +00:00
Dmitry Chagin
b2421c29f6 as suggested by jhb@, panic in case the ncpus == 0.
it helps to catch bugs in the callers.

Approved by:	kib (mentor)
MFC after:	5 days
2009-03-03 17:34:09 +00:00
Dmitry Chagin
6485a22ccb Fix range-check error introduced in r182292. Also do not do anything
if all processors in the map are not available, simply return.

Approved by:	kib (mentor)
MFC after:	1 week
2009-03-01 14:26:24 +00:00
John Baldwin
4e30a2db51 Whitespace tweak. 2009-01-26 15:32:39 +00:00
John Baldwin
4482f952b1 Adjust the license statement to more closely match a standard 3-clause BSD
license.

MFC after:	3 days
2008-11-03 21:17:02 +00:00
John Baldwin
9c2bf0cce2 - Only count the number of CPUs in the rendezvous map once rather than
doing it on every CPU.
- Use CPU_ABSENT() rather than pcpu_find() to determine if a CPU is not
  present.
- Count up to mp_maxid rather than MAXCPU when iterating over CPUs to
  match the rest of the code in the kernel.

MFC after:	1 week
2008-08-27 18:23:55 +00:00
John Birrell
833b4a131a Allow a rendezvous with just a specified CPU too.
Make the API work in the non-smp case too so that a kernel module
can work the same regardless of whether or not it is loaded on a SMP
kernel or not.
2008-05-23 04:05:26 +00:00
Robert Watson
237fdd787b In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation.  This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after:	1 month
Discussed with:	imp, rink
2008-03-16 10:58:09 +00:00
Jeff Roberson
1bf6461e98 - Add the missing '2' case to the switch table for kern.smp.topology and
assign it to create the flat 'none' topology where all cpus are scheduled
   as if they are equal and unrelated.
2008-03-10 01:38:53 +00:00