Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ (28b4d5cc) · Commits · e / devices / android_kernel_fairphone_FP5

Documentation/RCU/trace.txt

+49 −205

Original line number	Original line	Diff line number	Diff line
	CONFIG_RCU_TRACE debugfs Files and Formats		CONFIG_RCU_TRACE debugfs Files and Formats


	The rcupreempt and rcutree implementations of RCU provide debugfs trace		The rcutree implementation of RCU provides debugfs trace output that
	output that summarizes counters and state. This information is useful for		summarizes counters and state. This information is useful for debugging
	debugging RCU itself, and can sometimes also help to debug abuses of RCU.		RCU itself, and can sometimes also help to debug abuses of RCU.
	Note that the rcuclassic implementation of RCU does not provide debugfs		The following sections describe the debugfs files and formats.
	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.


	Hierarchical RCU debugfs Files and Formats		Hierarchical RCU debugfs Files and Formats
	@@ -210,9 +35,10 @@ rcu_bh:
	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		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		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		The first section lists the rcu_data structures for rcu_sched, the second
	rcu_bh. Each section has one line per CPU, or eight for this 8-CPU system.		for rcu_bh. Note that CONFIG_TREE_PREEMPT_RCU kernels will have an
	The fields are as follows:		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.		o The number at the beginning of each line is the CPU number.
	CPUs numbers followed by an exclamation mark are offline,		CPUs numbers followed by an exclamation mark are offline,
	@@ -223,9 +49,9 @@ o The number at the beginning of each line is the CPU number.

	o "c" is the count of grace periods that this CPU believes have		o "c" is the count of grace periods that this CPU believes have
	completed. CPUs in dynticks idle mode may lag quite a ways		completed. CPUs in dynticks idle mode may lag quite a ways
	behind, for example, CPU 4 under "rcu" above, which has slept		behind, for example, CPU 4 under "rcu_sched" above, which has
	through the past 25 RCU grace periods. It is not unusual to		slept through the past 25 RCU grace periods. It is not unusual
	see CPUs lagging by thousands of grace periods.		to see CPUs lagging by thousands of grace periods.

	o "g" is the count of grace periods that this CPU believes have		o "g" is the count of grace periods that this CPU believes have
	started. Again, CPUs in dynticks idle mode may lag behind.		started. Again, CPUs in dynticks idle mode may lag behind.
	@@ -308,8 +134,10 @@ The output of "cat rcu/rcugp" looks as follows:
	rcu_sched: completed=33062 gpnum=33063		rcu_sched: completed=33062 gpnum=33063
	rcu_bh: completed=464 gpnum=464		rcu_bh: completed=464 gpnum=464

	Again, this output is for both "rcu" and "rcu_bh". The fields are		Again, this output is for both "rcu_sched" and "rcu_bh". Note that
	taken from the rcu_state structure, and are as follows:		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.		o "completed" is the number of grace periods that have completed.
	It is comparable to the "c" field from rcu/rcudata in that a		It is comparable to the "c" field from rcu/rcudata in that a
	@@ -324,23 +152,24 @@ o "gpnum" is the number of grace periods that have started. It is
	If these two fields are equal (as they are for "rcu_bh" above),		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		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		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:		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		c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6 oqlen=0
	1/1 0:127 ^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		3/3 .>. 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		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:		rcu_bh:
	c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0		c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0 oqlen=0
	0/1 0:127 ^0		0/1 .>. 0:127 ^0
	0/3 0:35 ^0 0/0 36:71 ^1 0/0 72:107 ^2 0/0 108:127 ^3		0/3 .>. 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		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		This is once again split into "rcu_sched" and "rcu_bh" portions,
	as follows:		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.		o "c" is exactly the same as "completed" under rcu/rcugp.

	@@ -372,6 +201,11 @@ o "fqlh" is the number of calls to force_quiescent_state() that
	exited immediately (without even being counted in nfqs above)		exited immediately (without even being counted in nfqs above)
	due to contention on ->fqslock.		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		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		rcu_node. Each line represents one level of the hierarchy, from
	root to leaves. It is best to think of the rcu_data structures		root to leaves. It is best to think of the rcu_data structures
	@@ -389,10 +223,19 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
	The value of qsmaskinit is assigned to that of qsmask		The value of qsmaskinit is assigned to that of qsmask
	at the beginning of each grace period.		at the beginning of each grace period.

	For example, for "rcu", the qsmask of the first entry		For example, for "rcu_sched", the qsmask of the first
	of the lowest level is 0x14, meaning that we are still		entry of the lowest level is 0x14, meaning that we
	waiting for CPUs 2 and 4 to check in for the current		are still waiting for CPUs 2 and 4 to check in for the
	grace period.		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		o The numbers separated by the ":" are the range of CPUs
	served by this struct rcu_node. This can be helpful		served by this struct rcu_node. This can be helpful
	@@ -431,8 +274,9 @@ rcu_bh:
	6 np=120834 qsp=9902 cbr=0 cng=0 gpc=6 gps=3 nf=2 nn=110921		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		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.		As always, this is once again split into "rcu_sched" and "rcu_bh"
	The fields are as follows:		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		o "np" is the number of times that __rcu_pending() has been invoked
	for the corresponding flavor of RCU.		for the corresponding flavor of RCU.

Documentation/RCU/whatisRCU.txt

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -830,7 +830,7 @@ sched: Critical sections Grace period Barrier
	SRCU: Critical sections Grace period Barrier		SRCU: Critical sections Grace period Barrier

	srcu_read_lock synchronize_srcu N/A		srcu_read_lock synchronize_srcu N/A
	srcu_read_unlock		srcu_read_unlock synchronize_srcu_expedited

	SRCU: Initialization/cleanup		SRCU: Initialization/cleanup
	init_srcu_struct		init_srcu_struct

Documentation/dontdiff

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -65,6 +65,7 @@ aicdb.h*
	asm-offsets.h		asm-offsets.h
	asm_offsets.h		asm_offsets.h
	autoconf.h*		autoconf.h*
			av_permissions.h
	bbootsect		bbootsect
	bin2c		bin2c
	binkernel.spec		binkernel.spec
	@@ -95,12 +96,14 @@ docproc
	elf2ecoff		elf2ecoff
	elfconfig.h*		elfconfig.h*
	fixdep		fixdep
			flask.h
	fore200e_mkfirm		fore200e_mkfirm
	fore200e_pca_fw.c*		fore200e_pca_fw.c*
	gconf		gconf
	gen-devlist		gen-devlist
	gen_crc32table		gen_crc32table
	gen_init_cpio		gen_init_cpio
			genheaders
	genksyms		genksyms
	*_gray256.c		*_gray256.c
	ihex2fw		ihex2fw

Documentation/kernel-parameters.txt

+16 −12

Original line number	Original line	Diff line number	Diff line
	@@ -85,7 +85,6 @@ parameter is applicable:
	PPT Parallel port support is enabled.		PPT Parallel port support is enabled.
	PS2 Appropriate PS/2 support is enabled.		PS2 Appropriate PS/2 support is enabled.
	RAM RAM disk support is enabled.		RAM RAM disk support is enabled.
	ROOTPLUG The example Root Plug LSM is enabled.
	S390 S390 architecture is enabled.		S390 S390 architecture is enabled.
	SCSI Appropriate SCSI support is enabled.		SCSI Appropriate SCSI support is enabled.
	A lot of drivers has their options described inside of		A lot of drivers has their options described inside of
	@@ -779,6 +778,13 @@ and is between 256 and 4096 characters. It is defined in the file
	by the set_ftrace_notrace file in the debugfs		by the set_ftrace_notrace file in the debugfs
	tracing directory.		tracing directory.

			ftrace_graph_filter=[function-list]
			[FTRACE] Limit the top level callers functions traced
			by the function graph tracer at boot up.
			function-list is a comma separated list of functions
			that can be changed at run time by the
			set_graph_function file in the debugfs tracing directory.

	gamecon.map[2\|3]=		gamecon.map[2\|3]=
	[HW,JOY] Multisystem joystick and NES/SNES/PSX pad		[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
	support via parallel port (up to 5 devices per port)		support via parallel port (up to 5 devices per port)
	@@ -2032,8 +2038,15 @@ and is between 256 and 4096 characters. It is defined in the file

	print-fatal-signals=		print-fatal-signals=
	[KNL] debug: print fatal signals		[KNL] debug: print fatal signals
	print-fatal-signals=1: print segfault info to
	the kernel console.		If enabled, warn about various signal handling
			related application anomalies: too many signals,
			too many POSIX.1 timers, fatal signals causing a
			coredump - etc.

			If you hit the warning due to signal overflow,
			you might want to try "ulimit -i unlimited".

	default: off.		default: off.

	printk.time= Show timing data prefixed to each printk message line		printk.time= Show timing data prefixed to each printk message line
	@@ -2164,15 +2177,6 @@ and is between 256 and 4096 characters. It is defined in the file
	Useful for devices that are detected asynchronously		Useful for devices that are detected asynchronously
	(e.g. USB and MMC devices).		(e.g. USB and MMC devices).

	root_plug.vendor_id=
	[ROOTPLUG] Override the default vendor ID

	root_plug.product_id=
	[ROOTPLUG] Override the default product ID

	root_plug.debug=
	[ROOTPLUG] Enable debugging output

	rw [KNL] Mount root device read-write on boot		rw [KNL] Mount root device read-write on boot

	S [KNL] Run init in single mode		S [KNL] Run init in single mode

Documentation/pcmcia/driver-changes.txt

+12 −0

Original line number	Original line	Diff line number	Diff line
	This file details changes in 2.6 which affect PCMCIA card driver authors:		This file details changes in 2.6 which affect PCMCIA card driver authors:

			* no cs_error / CS_CHECK / CONFIG_PCMCIA_DEBUG (as of 2.6.33)
			Instead of the cs_error() callback or the CS_CHECK() macro, please use
			Linux-style checking of return values, and -- if necessary -- debug
			messages using "dev_dbg()" or "pr_debug()".

			* New CIS tuple access (as of 2.6.33)
			Instead of pcmcia_get_{first,next}_tuple(), pcmcia_get_tuple_data() and
			pcmcia_parse_tuple(), a driver shall use "pcmcia_get_tuple()" if it is
			only interested in one (raw) tuple, or "pcmcia_loop_tuple()" if it is
			interested in all tuples of one type. To decode the MAC from CISTPL_FUNCE,
			a new helper "pcmcia_get_mac_from_cis()" was added.

	* New configuration loop helper (as of 2.6.28)		* New configuration loop helper (as of 2.6.28)
	By calling pcmcia_loop_config(), a driver can iterate over all available		By calling pcmcia_loop_config(), a driver can iterate over all available
	configuration options. During a driver's probe() phase, one doesn't need		configuration options. During a driver's probe() phase, one doesn't need