83033 Commits

Author SHA1 Message Date
Justin T. Gibbs
ba12978b8a sys/cam/scsi/scsi_da.c:
- Only attempt the closing synchronize cache on a disk
	  if it is still there.
	- When a device is lost, report the number of outstanding
	  I/Os as they are drained.
	- When a device is lost, return any unprocessed bios with
	  ENXIO instead of EIO.
	- Filter asynchronous events, but always allow cam_periph_async()
	  to see them too.

Sponsored by:	Spectra Logic Corporation
2011-06-14 16:05:00 +00:00
Justin T. Gibbs
3501942bbe Lay groundwork in CAM for recording and reporting physical path and
other device attributes stored in the CAM Existing Device Table (EDT).
This includes some infrastructure requried by the enclosure services
driver to export physical path information.

Make the CAM device advanced info interface accept store requests.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	- Replace scsi_get_sas_addr() with a scsi_get_devid() which takes
	  a callback that decides whether to accept a particular descriptor.
	  Provide callbacks for NAA IEEE Registered addresses and for SAS
	  addresses, replacing the old function.  This is needed because
	  the old function doesn't work for an enclosure address for a SAS
	  device, which is not flagged as a SAS address, but is NAA IEEE
	  Registered.  It may be worthwhile merging this interface with the
	  devid match interface.
	- Add a few more defines for some device ID fields.

  sbin/camcontrol/camcontrol.c:
	- Update for the CCB_DEV_ADVINFO interface change.

  cam/cam_xpt_internal.h:
	- Add the new fields for the physical path string to the CAM EDT.
  cam/cam_ccb.h:
	- Rename CCB_GDEV_ADVINFO to simply CCB_DEV_ADVINFO, and the ccb
	  structure to ccb_dev_advinfo.
	- Add a flag that changes this CCB's action to store, rather than
	  the default, retrieve.
	- Add a new buffer type, CDAI_TYPE_PHYS_PATH, for the new CAM EDT
	  physpath field.
	- Remove the never-implemented transport & proto flags.
  cam/cam_xpt.c:
  cam/cam_xpt.h:
	- Add xpt_getattr(), which provides a wrapper for fetching a device's
	  attribute using the GEOM strings as key.  This method currently
	  supports "GEOM::ident" and "GEOM::physpath".

Submitted by: will
Reviewed by : gibbs

Extend the XPT_DEV_MATCH api to allow a device search by device ID.
As far as the API is concerned, device ID is a binary blob to be
interpreted by the transport layer.  The SCSI implementation assumes
it is an array of VPD device ID descriptors.

  sys/cam/cam_ccb.h:
	Create a new structure, device_id_match_pattern, and
	update the XPT_DEV_MATCH datastructures and flags so
	that this pattern type can be used.

  sys/cam/cam_xpt.c:
	- A single pattern matching on both inquiry data and device
	  ID is invalid.  Report any violators.
	- Pass device ID match requests through to the new routine
	  scsi_devid_match().  The direct call of a SCSI routine is
	  a layering violation, but no worse than the one a few
	  lines up that checks inquiry data.  Defer cleaning this
	  up until our future, larger, rototilling of CAM.
	- Zero out cam_ed and cam_et nodes on allocation.  Prior to
	  this change, device_id_len and device_id were not inialized,
	  preventing proper detection of the presence of this
	  information.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	Add the scsi_match_devid() routine.

Add a helper function for extracting peripherial driver names

  sys/cam/cam_periph.c:
  sys/cam/cam_periph.h:
	Add the cam_periph_list() method which fills an sbuf
	with a comma delimited list of the peripheral instances
	associated with a given CAM path.

Add a helper functions for SCSI commands used by the SES driver.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	Add structure definitions and csio filling functions for
	the receive diagnostic results and send diagnostic commands.

Misc CAM XPT cleanups.

  sys/cam/cam_xpt.c:
	Broadcast AC_FOUND_DEVICE and AC_PATH_REGISTERED
	events at the time async event handlers are attached
	even when registering just for events on a partitular
	SIM.  Previously, you had to register for these
	events on all SIMs in the system in order to get
	the initial broadcast even though subsequent device
	and path arrivals would be delivered.

  sys/cam/cam_xpt.c:
	Remove SIM mutex held asserts from path accessors.
	CAM paths are reference counted and it is this
	reference count, not the sim mutex, that garantees
	they are stable.

Sponsored by: Spectra Logic Corporation
2011-06-14 14:53:17 +00:00
Andrey V. Elsukov
1875bbfe54 Implement "global" mode for ipfw nat. It is similar to natd(8)
"globalport" option for multiple NAT instances.

If ipfw rule contains "global" keyword instead of nat_number, then
for each outgoing packet ipfw_nat looks up translation state in all
configured nat instances. If an entry is found, packet aliased
according to that entry, otherwise packet is passed unchanged.

User can specify "skip_global" option in NAT configuration to exclude
an instance from the lookup in global mode.

PR:		kern/157867
Submitted by:	Alexander V. Chernikov (previous version)
Tested by:	Eugene Grosbein
2011-06-14 13:35:24 +00:00
Luigi Rizzo
c9d658e9f7 Grab one of the ifcap bits for netmap, and enable printing in ifconfig.
Document the fact that we might want an IFCAP_CANTCHANGE mask,
even though the value is not yet used in sys/net/if.c

(asked on -current a week ago, no feedback so i assume no objection).
2011-06-14 12:40:55 +00:00
Andrey V. Elsukov
81a654646e Sort alias mode flags in the increasing order. 2011-06-14 12:06:38 +00:00
Andrey V. Elsukov
3265f69ce6 Add IPv6 support to the ipfw uid/gid check. Pass an ip_fw_args structure
to the check_uidgid() function, since it contains all needed arguments
and also pointer to mbuf and now it is possible use in_pcblookup_mbuf()
function.

Since i can not test it for the non-FreeBSD case, i keep this ifdef
unchanged.

Tested by:	Alexander V. Chernikov
MFC after:	3 weeks
2011-06-14 07:20:16 +00:00
Kenneth D. Merry
094efe753d Instead of using an atomic operation to determine whether the devstat(9)
device node has been created, pass MAKEDEV_CHECKNAME in so that the devfs
code will do the check.

Use a regular static variable as before, that's good enough to keep us from
calling into devfs most of the time.

Suggested by:	kib
MFC after:	1 week
Sponsored by:	Spectra Logic Corporation
2011-06-13 22:08:24 +00:00
Justin T. Gibbs
27c959cf05 Fix a couple of race conditions in devstat(9) initialization.
In devstat_new_entry(), there is no need to initialize the queue
and the mutex in this function.  There are ways to do static
initialization on both, so use STAILQ_HEAD_INITIALIZER and
MTX_SYSINIT to initialize the queue and the mutex.

In devstat_alloc(), use an atomic test and set routine to guard
making our entry in /dev.  Using just a plain static variable
creates a race condition on multiprocessor machines.  If you
attempt to create a second entry in devfs, the kernel will panic.

Submitted by:	kdm
Reviewed by:	gibbs
Sponsored by:	Spectra Logic Corporation
MFC after:	1 week.
2011-06-13 21:21:02 +00:00
Justin T. Gibbs
8a8a3387fd Several enhancements to the Xen block back driver.
sys/dev/xen/blkback/blkback.c:
	o Implement front-end request coalescing.  This greatly improves the
	  performance of front-end clients that are unaware of the dynamic
	  request-size/number of requests negotiation available in the
	  FreeBSD backend driver.  This required a large restructuring
	  in how this driver records in-flight transactions and how those
	  transactions are mapped into kernel KVA.  For example, the driver
	  now includes a mini "KVA manager" that allocates ranges of
	  contiguous KVA to patches of requests that are physically
	  contiguous in the backing store so that a single bio or UIO
	  segment can be used to represent the I/O.

	o Refuse to open any backend files or devices if the system
	  has yet to mount root.  This avoids a panic.

	o Properly handle "onlined" devices.  An "onlined" backend
	  device stays attached to its backing store across front-end
	  disconnections.  This feature is intended to reduce latency
	  when a front-end does a hand-off to another driver (e.g.
	  PV aware bootloader to OS kernel) or during a VM reboot.

	o Harden the driver against a pathological/buggy front-end
	  by carefully vetting front-end XenStore data such as the
	  front-end state.

	o Add sysctls that report the negotiated number of
	  segments per-request and the number of requests that
	  can be concurrently in flight.

Submitted by:	kdm
Reviewed by:	gibbs
Sponsored by:	Spectra Logic Corporation
MFC after:	1 week
2011-06-13 20:36:29 +00:00
Alexander Motin
180c2b3829 Add bunch of Conexant codec IDs. For some of them add quirks to disable
excessive signal paths to simplify tracer's life.
2011-06-13 20:34:12 +00:00
Dimitry Andric
222ef43340 Use alternative, less messy solution to avoid breakage after r223020:
put the snapdata structure between #ifdef _KERNEL guards.

Suggested by:	kib
2011-06-13 16:05:41 +00:00
John Baldwin
6b7c15e580 Advance the advertised window (rcv_adv) to the currently received data
(rcv_nxt) if we advertising a zero window.  This can be true when ACK'ing
a window probe whose one byte payload was accepted rather than dropped
because the socket's receive buffer was not completely full, but the
remaining space was smaller than the window scale.

This ensures that window probe ACKs satisfy the assumption made in r221346
and closes a window where rcv_nxt could be greater than rcv_adv.

Tested by:	trasz, pho, trociny
Reviewed by:	silby
MFC after:	1 week
2011-06-13 15:38:31 +00:00
Yoshihiro Takahashi
e8e9012af6 - Reduce diffs against i386.
- Add snd_uaudio.
2011-06-13 13:24:33 +00:00
Marius Strobl
2ba56f4d23 - Merge r222980 from x86: add sound(4) and common device drivers.
- Fix whitespace.
2011-06-13 12:45:19 +00:00
Adrian Chadd
76170c392d Fix ath_ahb(4) bus attach and eeprom error handling.
Submitted by:	Luiz Otavio O Souza <loos.br@gmail.com>
2011-06-13 04:31:57 +00:00
Xin LI
357a26abb1 Use swap32() right.
Submitted by:	gcopper
MFC after:	2 weeks
2011-06-12 23:33:08 +00:00
Kirk McKusick
9eb8728aa5 Update to soft updates journaling to properly track freed blocks
that get claimed by snapshots.

Submitted by:	Jeff Roberson
Tested by:	Peter Holm
2011-06-12 19:27:05 +00:00
Alexander Motin
8e6cab54e8 Do not report CFA devices as ATAPI, even though IDENTIFY data look alike. 2011-06-12 18:52:39 +00:00
Kirk McKusick
9420dc62cd Disable the soft updates journaling after a filesystem is successfully
downgraded to read-only. It will be restarted if the filesystem is
upgraded back to read-write.
2011-06-12 18:46:48 +00:00
Dimitry Andric
bd5abe1968 Upgrade our copy of llvm/clang to r132879, from upstream's trunk. 2011-06-12 18:01:31 +00:00
Konstantin Belousov
3b1025d200 Assert that page is VPO_BUSY or page owner object is locked in
vm_page_undirty(). The assert is not precise due to VPO_BUSY owner
to tracked, so assertion does not catch the case when VPO_BUSY is
owned by other thread.

Reviewed by:	alc
2011-06-11 20:15:19 +00:00
Konstantin Belousov
9d17da3bef Fix a bug in r222586. Lock the page owner object around the modification
of the m->dirty.

Reported and tested by:	nwhitehorn
Reviewed by:	alc
2011-06-11 20:13:28 +00:00
Nathan Whitehorn
698ef695bc Follow up r222980 on PowerPC: add sound(4) and common device drivers
to PowerPC GENERIC (along with a small rearrangement).
2011-06-11 12:34:08 +00:00
Joel Dahl
701b698b6f Enable sound support by default on i386 and amd64.
The generic sound driver has been added, along with enough
device-specific drivers to support the most common audio
chipsets.

We've discussed enabling it from time to time over the years
and we've received numerous requests from users, so we decided
that shipping 9.0 with working audio by default would be the
best thing to do.

Bug reports should be sent to the multimedia@ mailing list, as
usual.

Approved by:    mav
No objection:   re
2011-06-11 09:08:46 +00:00
Justin T. Gibbs
283d6f7287 Monitor and emit events for XenStore changes to XenBus trees
of the devices we manage.  These changes can be due to writes
we make ourselves or due to changes made by the control domain.
The goal of these changes is to insure that all state transitions
can be detected regardless of their source and to allow common
device policies (e.g. "onlined" backend devices) to be centralized
in the XenBus bus code.

sys/xen/xenbus/xenbusvar.h:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_if.m:
	Add a new method for XenBus drivers "localend_changed".
	This method is invoked whenever a write is detected to
	a device's XenBus tree.  The default implementation of
	this method is a no-op.

sys/xen/xenbus/xenbus_if.m:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
	Change the signature of the "otherend_changed" method.
	This notification cannot fail, so it should return void.

sys/xen/xenbus/xenbusb_back.c:
	Add "online" device handling to the XenBus Back Bus
	support code.  An online backend device remains active
	after a front-end detaches as a reconnect is expected
	to occur in the near future.

sys/xen/interface/io/xenbus.h:
	Add comment block further explaining the meaning and
	driver responsibilities associated with the XenBus
	Closed state.

sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
sys/xen/xenbus/xenbusb_back.c:
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusb_if.m:
	o Register a XenStore watch against the local XenBus tree
	  for all devices.
	o Cache the string length of the path to our local tree.
	o Allow the xenbus front and back drivers to hook/filter both
	  local and otherend watch processing.
	o Update the device ivar version of "state" when we detect
	  a XenStore update of that node.

sys/dev/xen/control/control.c:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenstore/xenstorevar.h:
	Allow clients of the XenStore watch mechanism to attach
	a single uintptr_t worth of client data to the watch.
	This removes the need to carefully place client watch
	data within enclosing objects so that a cast or offsetof
	calculation can be used to convert from watch to enclosing
	object.

Sponsored by:	Spectra Logic Corporation
MFC after:	1 week
2011-06-11 04:59:01 +00:00
Navdeep Parhar
59bc8ce035 - driver ioctl to get SGE context for any given queue.
- sysctls to display the context id, cidx, and pidx of all kinds of queues.

MFC after:	3 days
2011-06-11 04:50:54 +00:00
Marcel Moolenaar
52737ec557 Add the model number for the Montvale processor (marketed as Itanium 2 9100).
At this time we're missing just one: Tukwila (Itanium 2 9300).
2011-06-11 02:22:11 +00:00
Xin LI
97ae66672f Add comments about the validation. 2011-06-11 01:19:19 +00:00
Jeff Roberson
280e091a99 Implement fully asynchronous partial truncation with softupdates journaling
to resolve errors which can cause corruption on recovery with the old
synchronous mechanism.

 - Append partial truncation freework structures to indirdeps while
   truncation is proceeding.  These prevent new block pointers from
   becoming valid until truncation completes and serialize truncations.
 - On completion of a partial truncate journal work waits for zeroed
   pointers to hit indirects.
 - softdep_journal_freeblocks() handles last frag allocation and last
   block zeroing.
 - vtruncbuf/ffs_page_remove moved into softdep_*_freeblocks() so it
   is only implemented in one place.
 - Block allocation failure handling moved up one level so it does not
   proceed with buf locks held.  This permits us to do more extensive
   reclaims when filesystem space is exhausted.
 - softdep_sync_metadata() is broken into two parts, the first executes
   once at the start of ffs_syncvnode() and flushes truncations and
   inode dependencies.  The second is called on each locked buf.  This
   eliminates excessive looping and rollbacks.
 - Improve the mechanism in process_worklist_item() that handles
   acquiring vnode locks for handle_workitem_remove() so that it works
   more generally and does not loop excessively over the same worklist
   items on each call.
 - Don't corrupt directories by zeroing the tail in fsck.  This is only
   done for regular files.
 - Push a fsync complete record for files that need it so the checker
   knows a truncation in the journal is no longer valid.

Discussed with:	mckusick, kib (ffs_pages_remove and ffs_truncate parts)
Tested by:	pho
2011-06-10 22:48:35 +00:00
Jeff Roberson
e4a06afe93 - Eliminate an incorrect include path from the mthca build. 2011-06-10 22:38:31 +00:00
Jeff Roberson
e84fa3ba71 - Add support for referencing quota structures without needing the inode
pointer for softupdates.

Submitted by:	mckusick
2011-06-10 22:19:44 +00:00
Jeff Roberson
5aa336ed20 - If the fsync in ufs_direnter fails SUJ can later panic because we have
partially added a name.  Allow ufs_direnter() to continue in the
   hopes that it is a transient error.  If it is not, the directory
   is corrupted already from IO errors and writing this new block
   is not likely to make things worse.
2011-06-10 22:18:25 +00:00
Jeff Roberson
6f59b2bd33 - When printing bufs with show buf the lblkno is often more useful than
the blkno.  Print them both.
2011-06-10 22:15:36 +00:00
Justin T. Gibbs
e1f3ca6edc Include sys/xen in cscope tag file generation. 2011-06-10 20:51:41 +00:00
Attilio Rao
1bd320ec51 - Fix races on detach handling of AAC_IFFLAGS_* mask
- Fix races on setting AAC_AIFFLAGS_ALLOCFIBS
- Remove some unused AAC_IFFLAGS_* bits.
  Please note that the kthread still makes a difference between the
  total mask and AAC_AIFFLAGS_ALLOCFIBS because more flags may be
  added in the future to aifflags.

Sponsored by:			Sandvine Incorporated
Reported and reviewed by:	emaste
MFC after:			2 weeks
2011-06-10 20:23:56 +00:00
Justin T. Gibbs
1c3bf59584 Remove C constructs that are incompatible with C++ from various
OpenSolaris and ZFS header files.  These changes are sufficient
to allow a C++ program to use the libzfs library.

Note: The majority of these files already included 'extern "C"'
      declarations, so the intention of providing C++ compatibility
      already existed even if it wasn't provided.

cddl/compat/opensolaris/include/assert.h:
	Wrap our compatibility assert implementation in
	'extern "C"'.  Since this is a compatibility header
	I matched the Solaris style of doing this explicitly
	rather than rely on FreeBSD's __BEGIN/END_DECLS macro.

sys/cddl/compat/opensolaris/sys/kstat.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/arc.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_pool.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/ddt.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio.h:
	Rename parameters in function declarations that conflict
	with C++ keywords.  This was the solution preferred by
	members of the Illumos community.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_ioctl.h:
	In C, nested structures are visible in the global namespace,
	but in C++, they take on the namespace of the structure in
	which they are contained.  Flatten nested structure
	definitions within struct zfs_cmd so these structures are
	visible in the global namespace when compiled in both
	languages.

Sponsored by:	 Spectra Logic Corporation
2011-06-10 20:10:30 +00:00
Bernhard Schmidt
19da774130 Make sure to drop the IEEE80211_RATE_BASIC flag even for MCS rates.
Reported by:	Maciej Milewski <milu at dat dot pl>
Tested by:	Maciej Milewski <milu at dat dot pl>
2011-06-10 17:06:25 +00:00
John Baldwin
a49dcb469c Fix some off-by-one errors with the ending address of candidate regions
when attempting to grow a window.
2011-06-10 13:24:56 +00:00
John Baldwin
049dc0d1ff Implement BUS_ADJUST_RESOURCE() for the x86 drivers that sit between the
Host-PCI bridge drivers and nexus.
2011-06-10 12:30:16 +00:00
Nathan Whitehorn
b9856e92ac Add -Wa,-many to CFLAGS on PowerPC. This aids in building a kernel using
clang, which would otherwise complain about some 64-bit bridge mode
instructions.
2011-06-09 19:47:30 +00:00
Alexander Motin
0eac2d6be3 Intel NM10 chipset's SATA controller has same PCI ID and revision as ICH7's,
but has only 2 SATA ports instead of 4. The worst part is that SStatus and
SError registers for missing ports are not implemented and return wrong
values (0xffffffff), that caused infinite reset loop.

Just ignore that SError value while I found no better way to identify them.
2011-06-09 16:30:13 +00:00
Jung-uk Kim
bc8e4ad2ef Tidy up r222866.
- Re-add accidentally removed atomic op. for sysctl(9) handler.
- Remove a period(`.') at the end of a debugging message.
- Consistently spell "low" for "TSC-low" timecounter throughout.

Pointed out by:	bde
2011-06-08 23:44:59 +00:00
David Christensen
76dbe6498b - Major reorganization of mbuf handling throughout the driver to
increase robustness (no more calls to panic(9)) and simplify
  code.
- Allocate RX/TX data structures as a single buffer rather than
  an array of 4KB pages to simplify code.
- Fixed LRO (aka TPA) code.  Removed kernel module parameter and
  support enabling disabling LRO through ifconfig(8) command line.
  LRO is still disabled by default but should be enabled for best
  performance on an endpoint device.
- Fixed statistcs code and removed kernel module parameter (stats
  should just work).
- Added many software counters to help identify the cause of some
  performance issues.
- Streamlined adapter internal init/stop code paths.
- Fiddled with debug code (adding some here, removing some there).
- Continued style(9) adjustments.
2011-06-08 21:18:14 +00:00
Jung-uk Kim
26e6537a73 Increase quality of TSC (or TSC-low) timecounter to 1000 if it is P-state
invariant.  For SMP case (TSC-low), it also has to pass SMP synchronization
test and the CPU vendor/model has to be white-listed explicitly.  Currently,
all Intel CPUs and single-socket AMD Family 15h processors are listed here.

Discussed with:	hackers
2011-06-08 20:08:06 +00:00
Jung-uk Kim
95f2f0985b Introduce low-resolution TSC timecounter "TSC-low". It replaces the normal
TSC timecounter if TSC frequency is higher than ~4.29 MHz (or 2^32-1 Hz) or
multiple CPUs are present.  The "TSC-low" frequency is always lower than a
preset maximum value and derived from TSC frequency (by being halved until
it becomes lower than the maximum).  Note the maximum value for SMP case is
significantly lower than UP case because we want to reduce (rare but known)
"temporal anomalies" caused by non-serialized RDTSC instruction.  Normally,
it is still higher than "ACPI-fast" timecounter frequency (which was default
timecounter hardware for long time until r222222) to be useful.
2011-06-08 19:38:31 +00:00
Attilio Rao
e3adb68519 In the current code, a double panic condition may lead to dumps
interleaving.
Signal dumping to happen only for the first panic which should be the
most important.

Sponsored by:	Sandvine Incorporated
Submitted by:	Nima Misaghian (nmisaghian AT sandvine DOT com)
MFC after:	2 weeks
2011-06-08 19:28:59 +00:00
Jung-uk Kim
75aa1914d5 Remove a redundant assignment since r221703. 2011-06-08 18:52:42 +00:00
Andreas Tobler
d91c258074 - Improve error handling.
- Add retry loops in the i2c read/write functions.
- Combied the ADC channel selection and readout of the value into
  one iicbus_transfer to avoid possible races.

Reviewed by: nwhitehorn
2011-06-08 16:00:30 +00:00
Bjoern A. Zeeb
869052041d Add the missing call to ip6_ipsec_filtertunnel() to be able to control
whether decapsulated IPsec packets will be passed to pfil again depending
on the setting of the net.ip6.ipsec6.filtertunnel sysctl.

PR:		kern/157670
Submitted by:	Manuel Kasper (mk neon1.net)
MFC after:	2 weeks
2011-06-08 10:59:36 +00:00
Andriy Gapon
234dab4a82 remove code for dynamic offlining/onlining of CPUs on x86
The code has definitely been broken for SCHED_ULE, which is a default
scheduler.  It may have been broken for SCHED_4BSD in more subtle ways,
e.g. with manually configured CPU affinities and for interrupt devilery
purposes.
We still provide a way to disable individual CPUs or all hyperthreading
"twin" CPUs before SMP startup.  See the UPDATING entry for details.

Interaction between building CPU topology and disabling CPUs still
remains fuzzy: topology is first built using all availble CPUs and then
the disabled CPUs should be "subtracted" from it.  That doesn't work
well if the resulting topology becomes non-uniform.

This work is done in cooperation with Attilio Rao who in addition to
reviewing also provided parts of code.

PR:		kern/145385
Discussed with:	gcooper, ambrisko, mdf, sbruno
Reviewed by:	attilio
Tested by:	pho, pluknet
X-MFC after:	never
2011-06-08 08:12:15 +00:00