Merge branch 'linus' into x86/urgent

*.elf

*.bin

*.gz

*.bz2

*.lzma

*.patch

*.gcno

What:      /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X

Date:      August 2008

KernelVersion:	2.6.27

Contact:	mark.langsdorf@amd.com

Description:	These files exist in every cpu's cache index directories.

		There are currently 2 cache_disable_# files in each

		directory.  Reading from these files on a supported

		processor will return that cache disable index value

		for that processor and node.  Writing to one of these

		files will cause the specificed cache index to be disabled.

		Currently, only AMD Family 10h Processors support cache index

		disable, and only for their L3 caches.  See the BIOS and

		Kernel Developer's Guide at

		http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf

		for formatting information and other details on the

		cache index disable.

Users:    joachim.deguara@amd.com

What:		/sys/devices/system/cpu/

Date:		pre-git history

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:

		A collection of both global and individual CPU attributes

		Individual CPU attributes are contained in subdirectories

		named by the kernel's logical CPU number, e.g.:

		/sys/devices/system/cpu/cpu#/

What:		/sys/devices/system/cpu/sched_mc_power_savings

		/sys/devices/system/cpu/sched_smt_power_savings

Date:		June 2006

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	Discover and adjust the kernel's multi-core scheduler support.

		Possible values are:

		0 - No power saving load balance (default value)

		1 - Fill one thread/core/package first for long running threads

		2 - Also bias task wakeups to semi-idle cpu package for power

		    savings

		sched_mc_power_savings is dependent upon SCHED_MC, which is

		itself architecture dependent.

		sched_smt_power_savings is dependent upon SCHED_SMT, which

		is itself architecture dependent.

		The two files are independent of each other. It is possible

		that one file may be present without the other.

		Introduced by git commit 5c45bf27.

What:		/sys/devices/system/cpu/kernel_max

		/sys/devices/system/cpu/offline

		/sys/devices/system/cpu/online

		/sys/devices/system/cpu/possible

		/sys/devices/system/cpu/present

Date:		December 2008

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	CPU topology files that describe kernel limits related to

		hotplug. Briefly:

		kernel_max: the maximum cpu index allowed by the kernel

		configuration.

		offline: cpus that are not online because they have been

		HOTPLUGGED off or exceed the limit of cpus allowed by the

		kernel configuration (kernel_max above).

		online: cpus that are online and being scheduled.

		possible: cpus that have been allocated resources and can be

		brought online if they are present.

		present: cpus that have been identified as being present in

		the system.

		See Documentation/cputopology.txt for more information.

What:		/sys/devices/system/cpu/cpu#/node

Date:		October 2009

Contact:	Linux memory management mailing list <linux-mm@kvack.org>

Description:	Discover NUMA node a CPU belongs to

		When CONFIG_NUMA is enabled, a symbolic link that points

		to the corresponding NUMA node directory.

		For example, the following symlink is created for cpu42

		in NUMA node 2:

		/sys/devices/system/cpu/cpu42/node2 -> ../../node/node2

What:		/sys/devices/system/cpu/cpu#/topology/core_id

		/sys/devices/system/cpu/cpu#/topology/core_siblings

		/sys/devices/system/cpu/cpu#/topology/core_siblings_list

		/sys/devices/system/cpu/cpu#/topology/physical_package_id

		/sys/devices/system/cpu/cpu#/topology/thread_siblings

		/sys/devices/system/cpu/cpu#/topology/thread_siblings_list

Date:		December 2008

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	CPU topology files that describe a logical CPU's relationship

		to other cores and threads in the same physical package.

		One cpu# directory is created per logical CPU in the system,

		e.g. /sys/devices/system/cpu/cpu42/.

		Briefly, the files above are:

		core_id: the CPU core ID of cpu#. Typically it is the

		hardware platform's identifier (rather than the kernel's).

		The actual value is architecture and platform dependent.

		core_siblings: internal kernel map of cpu#'s hardware threads

		within the same physical_package_id.

		core_siblings_list: human-readable list of the logical CPU

		numbers within the same physical_package_id as cpu#.

		physical_package_id: physical package id of cpu#. Typically

		corresponds to a physical socket number, but the actual value

		is architecture and platform dependent.

		thread_siblings: internel kernel map of cpu#'s hardware

		threads within the same core as cpu#

		thread_siblings_list: human-readable list of cpu#'s hardware

		threads within the same core as cpu#

		See Documentation/cputopology.txt for more information.

What:		/sys/devices/system/cpu/cpuidle/current_driver

		/sys/devices/system/cpu/cpuidle/current_governer_ro

Date:		September 2007

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	Discover cpuidle policy and mechanism

		Various CPUs today support multiple idle levels that are

		differentiated by varying exit latencies and power

		consumption during idle.

		Idle policy (governor) is differentiated from idle mechanism

		(driver)

		current_driver: displays current idle mechanism

		current_governor_ro: displays current idle policy

		See files in Documentation/cpuidle/ for more information.

What:      /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X

Date:      August 2008

KernelVersion:	2.6.27

Contact:	mark.langsdorf@amd.com

Description:	These files exist in every cpu's cache index directories.

		There are currently 2 cache_disable_# files in each

		directory.  Reading from these files on a supported

		processor will return that cache disable index value

		for that processor and node.  Writing to one of these

		files will cause the specificed cache index to be disabled.

		Currently, only AMD Family 10h Processors support cache index

		disable, and only for their L3 caches.  See the BIOS and

		Kernel Developer's Guide at

		http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf

		for formatting information and other details on the

		cache index disable.

Users:    joachim.deguara@amd.com

!Iinclude/trace/events/irq.h

  </chapter>

  <chapter id="signal">

   <title>SIGNAL</title>

!Iinclude/trace/events/signal.h

  </chapter>

</book>

CONFIG_RCU_TRACE debugfs Files and Formats

The rcupreempt and rcutree implementations of RCU provide debugfs trace

output that summarizes counters and state.  This information is useful for

debugging RCU itself, and can sometimes also help to debug abuses of RCU.

Note that the rcuclassic implementation of RCU does not provide debugfs

trace output.

The following sections describe the debugfs files and formats for

preemptable RCU (rcupreempt) and hierarchical RCU (rcutree).

Preemptable RCU debugfs Files and Formats

This implementation of RCU provides three debugfs files under the

top-level directory RCU: rcu/rcuctrs (which displays the per-CPU

counters used by preemptable RCU) rcu/rcugp (which displays grace-period

counters), and rcu/rcustats (which internal counters for debugging RCU).

The output of "cat rcu/rcuctrs" looks as follows:

CPU last cur F M

  0    5  -5 0 0

  1   -1   0 0 0

  2    0   1 0 0

  3    0   1 0 0

  4    0   1 0 0

  5    0   1 0 0

  6    0   2 0 0

  7    0  -1 0 0

  8    0   1 0 0

ggp = 26226, state = waitzero

The per-CPU fields are as follows:

o	"CPU" gives the CPU number.  Offline CPUs are not displayed.

o	"last" gives the value of the counter that is being decremented

	for the current grace period phase.  In the example above,

	the counters sum to 4, indicating that there are still four

	RCU read-side critical sections still running that started

	before the last counter flip.

o	"cur" gives the value of the counter that is currently being

	both incremented (by rcu_read_lock()) and decremented (by

	rcu_read_unlock()).  In the example above, the counters sum to

	1, indicating that there is only one RCU read-side critical section

	still running that started after the last counter flip.

o	"F" indicates whether RCU is waiting for this CPU to acknowledge

	a counter flip.  In the above example, RCU is not waiting on any,

	which is consistent with the state being "waitzero" rather than

	"waitack".

o	"M" indicates whether RCU is waiting for this CPU to execute a

	memory barrier.  In the above example, RCU is not waiting on any,

	which is consistent with the state being "waitzero" rather than

	"waitmb".

o	"ggp" is the global grace-period counter.

o	"state" is the RCU state, which can be one of the following:

	o	"idle": there is no grace period in progress.

	o	"waitack": RCU just incremented the global grace-period

		counter, which has the effect of reversing the roles of

		the "last" and "cur" counters above, and is waiting for

		all the CPUs to acknowledge the flip.  Once the flip has

		been acknowledged, CPUs will no longer be incrementing

		what are now the "last" counters, so that their sum will

		decrease monotonically down to zero.

	o	"waitzero": RCU is waiting for the sum of the "last" counters

		to decrease to zero.

	o	"waitmb": RCU is waiting for each CPU to execute a memory

		barrier, which ensures that instructions from a given CPU's

		last RCU read-side critical section cannot be reordered

		with instructions following the memory-barrier instruction.

The output of "cat rcu/rcugp" looks as follows:

oldggp=48870  newggp=48873

Note that reading from this file provokes a synchronize_rcu().  The

"oldggp" value is that of "ggp" from rcu/rcuctrs above, taken before

executing the synchronize_rcu(), and the "newggp" value is also the

"ggp" value, but taken after the synchronize_rcu() command returns.

The output of "cat rcu/rcugp" looks as follows:

na=1337955 nl=40 wa=1337915 wl=44 da=1337871 dl=0 dr=1337871 di=1337871

1=50989 e1=6138 i1=49722 ie1=82 g1=49640 a1=315203 ae1=265563 a2=49640

z1=1401244 ze1=1351605 z2=49639 m1=5661253 me1=5611614 m2=49639

These are counters tracking internal preemptable-RCU events, however,

some of them may be useful for debugging algorithms using RCU.  In

particular, the "nl", "wl", and "dl" values track the number of RCU

callbacks in various states.  The fields are as follows:

o	"na" is the total number of RCU callbacks that have been enqueued

	since boot.

o	"nl" is the number of RCU callbacks waiting for the previous

	grace period to end so that they can start waiting on the next

	grace period.

o	"wa" is the total number of RCU callbacks that have started waiting

	for a grace period since boot.  "na" should be roughly equal to

	"nl" plus "wa".

o	"wl" is the number of RCU callbacks currently waiting for their

	grace period to end.

o	"da" is the total number of RCU callbacks whose grace periods

	have completed since boot.  "wa" should be roughly equal to

	"wl" plus "da".

o	"dr" is the total number of RCU callbacks that have been removed

	from the list of callbacks ready to invoke.  "dr" should be roughly

	equal to "da".

o	"di" is the total number of RCU callbacks that have been invoked

	since boot.  "di" should be roughly equal to "da", though some

	early versions of preemptable RCU had a bug so that only the

	last CPU's count of invocations was displayed, rather than the

	sum of all CPU's counts.

o	"1" is the number of calls to rcu_try_flip().  This should be

	roughly equal to the sum of "e1", "i1", "a1", "z1", and "m1"

	described below.  In other words, the number of times that

	the state machine is visited should be equal to the sum of the

	number of times that each state is visited plus the number of

	times that the state-machine lock acquisition failed.

o	"e1" is the number of times that rcu_try_flip() was unable to

	acquire the fliplock.

o	"i1" is the number of calls to rcu_try_flip_idle().

o	"ie1" is the number of times rcu_try_flip_idle() exited early

	due to the calling CPU having no work for RCU.

o	"g1" is the number of times that rcu_try_flip_idle() decided

	to start a new grace period.  "i1" should be roughly equal to

	"ie1" plus "g1".

o	"a1" is the number of calls to rcu_try_flip_waitack().

o	"ae1" is the number of times that rcu_try_flip_waitack() found

	that at least one CPU had not yet acknowledge the new grace period

	(AKA "counter flip").

o	"a2" is the number of time rcu_try_flip_waitack() found that

	all CPUs had acknowledged.  "a1" should be roughly equal to

	"ae1" plus "a2".  (This particular output was collected on

	a 128-CPU machine, hence the smaller-than-usual fraction of

	calls to rcu_try_flip_waitack() finding all CPUs having already

	acknowledged.)

o	"z1" is the number of calls to rcu_try_flip_waitzero().

o	"ze1" is the number of times that rcu_try_flip_waitzero() found

	that not all of the old RCU read-side critical sections had

	completed.

o	"z2" is the number of times that rcu_try_flip_waitzero() finds

	the sum of the counters equal to zero, in other words, that

	all of the old RCU read-side critical sections had completed.

	The value of "z1" should be roughly equal to "ze1" plus

	"z2".

o	"m1" is the number of calls to rcu_try_flip_waitmb().

o	"me1" is the number of times that rcu_try_flip_waitmb() finds

	that at least one CPU has not yet executed a memory barrier.

o	"m2" is the number of times that rcu_try_flip_waitmb() finds that

	all CPUs have executed a memory barrier.

The rcutree implementation of RCU provides debugfs trace output that

summarizes counters and state.  This information is useful for debugging

RCU itself, and can sometimes also help to debug abuses of RCU.

The following sections describe the debugfs files and formats.

Hierarchical RCU debugfs Files and Formats

  6 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=859/1 dn=0 df=15 of=0 ri=0 ql=0 b=10

  7 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=3761/1 dn=0 df=15 of=0 ri=0 ql=0 b=10

The first section lists the rcu_data structures for rcu, the second for

rcu_bh.  Each section has one line per CPU, or eight for this 8-CPU system.

The fields are as follows:

The first section lists the rcu_data structures for rcu_sched, the second

for rcu_bh.  Note that CONFIG_TREE_PREEMPT_RCU kernels will have an

additional section for rcu_preempt.  Each section has one line per CPU,

or eight for this 8-CPU system.  The fields are as follows:

o	The number at the beginning of each line is the CPU number.

	CPUs numbers followed by an exclamation mark are offline,

o	"c" is the count of grace periods that this CPU believes have

	completed.  CPUs in dynticks idle mode may lag quite a ways

	behind, for example, CPU 4 under "rcu" above, which has slept

	through the past 25 RCU grace periods.	It is not unusual to

	see CPUs lagging by thousands of grace periods.

	behind, for example, CPU 4 under "rcu_sched" above, which has

	slept through the past 25 RCU grace periods.  It is not unusual

	to see CPUs lagging by thousands of grace periods.

o	"g" is the count of grace periods that this CPU believes have

	started.  Again, CPUs in dynticks idle mode may lag behind.

rcu_sched: completed=33062  gpnum=33063

rcu_bh: completed=464  gpnum=464

Again, this output is for both "rcu" and "rcu_bh".  The fields are

taken from the rcu_state structure, and are as follows:

Again, this output is for both "rcu_sched" and "rcu_bh".  Note that

kernels built with CONFIG_TREE_PREEMPT_RCU will have an additional

"rcu_preempt" line.  The fields are taken from the rcu_state structure,

and are as follows:

o	"completed" is the number of grace periods that have completed.

	It is comparable to the "c" field from rcu/rcudata in that a

	If these two fields are equal (as they are for "rcu_bh" above),

	then there is no grace period in progress, in other words, RCU

	is idle.  On the other hand, if the two fields differ (as they

	do for "rcu" above), then an RCU grace period is in progress.

	do for "rcu_sched" above), then an RCU grace period is in progress.

The output of "cat rcu/rcuhier" looks as follows, with very long lines:

c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6

1/1 0:127 ^0    

3/3 0:35 ^0    0/0 36:71 ^1    0/0 72:107 ^2    0/0 108:127 ^3    

3/3f 0:5 ^0    2/3 6:11 ^1    0/0 12:17 ^2    0/0 18:23 ^3    0/0 24:29 ^4    0/0 30:35 ^5    0/0 36:41 ^0    0/0 42:47 ^1    0/0 48:53 ^2    0/0 54:59 ^3    0/0 60:65 ^4    0/0 66:71 ^5    0/0 72:77 ^0    0/0 78:83 ^1    0/0 84:89 ^2    0/0 90:95 ^3    0/0 96:101 ^4    0/0 102:107 ^5    0/0 108:113 ^0    0/0 114:119 ^1    0/0 120:125 ^2    0/0 126:127 ^3    

c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6 oqlen=0

1/1 .>. 0:127 ^0    

3/3 .>. 0:35 ^0    0/0 .>. 36:71 ^1    0/0 .>. 72:107 ^2    0/0 .>. 108:127 ^3    

3/3f .>. 0:5 ^0    2/3 .>. 6:11 ^1    0/0 .>. 12:17 ^2    0/0 .>. 18:23 ^3    0/0 .>. 24:29 ^4    0/0 .>. 30:35 ^5    0/0 .>. 36:41 ^0    0/0 .>. 42:47 ^1    0/0 .>. 48:53 ^2    0/0 .>. 54:59 ^3    0/0 .>. 60:65 ^4    0/0 .>. 66:71 ^5    0/0 .>. 72:77 ^0    0/0 .>. 78:83 ^1    0/0 .>. 84:89 ^2    0/0 .>. 90:95 ^3    0/0 .>. 96:101 ^4    0/0 .>. 102:107 ^5    0/0 .>. 108:113 ^0    0/0 .>. 114:119 ^1    0/0 .>. 120:125 ^2    0/0 .>. 126:127 ^3    

rcu_bh:

c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0

0/1 0:127 ^0    

0/3 0:35 ^0    0/0 36:71 ^1    0/0 72:107 ^2    0/0 108:127 ^3    

0/3f 0:5 ^0    0/3 6:11 ^1    0/0 12:17 ^2    0/0 18:23 ^3    0/0 24:29 ^4    0/0 30:35 ^5    0/0 36:41 ^0    0/0 42:47 ^1    0/0 48:53 ^2    0/0 54:59 ^3    0/0 60:65 ^4    0/0 66:71 ^5    0/0 72:77 ^0    0/0 78:83 ^1    0/0 84:89 ^2    0/0 90:95 ^3    0/0 96:101 ^4    0/0 102:107 ^5    0/0 108:113 ^0    0/0 114:119 ^1    0/0 120:125 ^2    0/0 126:127 ^3

c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0 oqlen=0

0/1 .>. 0:127 ^0    

0/3 .>. 0:35 ^0    0/0 .>. 36:71 ^1    0/0 .>. 72:107 ^2    0/0 .>. 108:127 ^3    

0/3f .>. 0:5 ^0    0/3 .>. 6:11 ^1    0/0 .>. 12:17 ^2    0/0 .>. 18:23 ^3    0/0 .>. 24:29 ^4    0/0 .>. 30:35 ^5    0/0 .>. 36:41 ^0    0/0 .>. 42:47 ^1    0/0 .>. 48:53 ^2    0/0 .>. 54:59 ^3    0/0 .>. 60:65 ^4    0/0 .>. 66:71 ^5    0/0 .>. 72:77 ^0    0/0 .>. 78:83 ^1    0/0 .>. 84:89 ^2    0/0 .>. 90:95 ^3    0/0 .>. 96:101 ^4    0/0 .>. 102:107 ^5    0/0 .>. 108:113 ^0    0/0 .>. 114:119 ^1    0/0 .>. 120:125 ^2    0/0 .>. 126:127 ^3

This is once again split into "rcu" and "rcu_bh" portions.  The fields are

as follows:

This is once again split into "rcu_sched" and "rcu_bh" portions,

and CONFIG_TREE_PREEMPT_RCU kernels will again have an additional

"rcu_preempt" section.  The fields are as follows:

o	"c" is exactly the same as "completed" under rcu/rcugp.

	exited immediately (without even being counted in nfqs above)

	due to contention on ->fqslock.

o	"oqlen" is the number of callbacks on the "orphan" callback

	list.  RCU callbacks are placed on this list by CPUs going

	offline, and are "adopted" either by the CPU helping the outgoing

	CPU or by the next rcu_barrier*() call, whichever comes first.

o	Each element of the form "1/1 0:127 ^0" represents one struct

	rcu_node.  Each line represents one level of the hierarchy, from

	root to leaves.  It is best to think of the rcu_data structures

		The value of qsmaskinit is assigned to that of qsmask

		at the beginning of each grace period.

		For example, for "rcu", the qsmask of the first entry

		of the lowest level is 0x14, meaning that we are still

		waiting for CPUs 2 and 4 to check in for the current

		grace period.

		For example, for "rcu_sched", the qsmask of the first

		entry of the lowest level is 0x14, meaning that we

		are still waiting for CPUs 2 and 4 to check in for the

		current grace period.

	o	The characters separated by the ">" indicate the state

		of the blocked-tasks lists.  A "T" preceding the ">"

		indicates that at least one task blocked in an RCU

		read-side critical section blocks the current grace

		period, while a "." preceding the ">" indicates otherwise.

		The character following the ">" indicates similarly for

		the next grace period.  A "T" should appear in this

		field only for rcu-preempt.

	o	The numbers separated by the ":" are the range of CPUs

		served by this struct rcu_node.  This can be helpful

  6 np=120834 qsp=9902 cbr=0 cng=0 gpc=6 gps=3 nf=2 nn=110921

  7 np=144888 qsp=26336 cbr=0 cng=0 gpc=8 gps=2 nf=0 nn=118542

As always, this is once again split into "rcu" and "rcu_bh" portions.

The fields are as follows:

As always, this is once again split into "rcu_sched" and "rcu_bh"

portions, with CONFIG_TREE_PREEMPT_RCU kernels having an additional

"rcu_preempt" section.  The fields are as follows:

o	"np" is the number of times that __rcu_pending() has been invoked

	for the corresponding flavor of RCU.