Merge commit '29ce831000081dd757d3116bf774aafffc4b6b20' into next (e3aa52d6) · Commits · e / devices / android_kernel_sony_msm8994

Documentation/RCU/00-INDEX

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -21,7 +21,7 @@ rcu.txt
	RTFP.txt		RTFP.txt
	- List of RCU papers (bibliography) going back to 1980.		- List of RCU papers (bibliography) going back to 1980.
	stallwarn.txt		stallwarn.txt
	- RCU CPU stall warnings (CONFIG_RCU_CPU_STALL_DETECTOR)		- RCU CPU stall warnings (module parameter rcu_cpu_stall_suppress)
	torture.txt		torture.txt
	- RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST)		- RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST)
	trace.txt		trace.txt

Documentation/RCU/stallwarn.txt

+13 −10

Original line number	Original line	Diff line number	Diff line
	Using RCU's CPU Stall Detector		Using RCU's CPU Stall Detector

	The CONFIG_RCU_CPU_STALL_DETECTOR kernel config parameter enables		The rcu_cpu_stall_suppress module parameter enables RCU's CPU stall
	RCU's CPU stall detector, which detects conditions that unduly delay		detector, which detects conditions that unduly delay RCU grace periods.
	RCU grace periods. The stall detector's idea of what constitutes		This module parameter enables CPU stall detection by default, but
	"unduly delayed" is controlled by a set of C preprocessor macros:		may be overridden via boot-time parameter or at runtime via sysfs.
			The stall detector's idea of what constitutes "unduly delayed" is
			controlled by a set of kernel configuration variables and cpp macros:

	RCU_SECONDS_TILL_STALL_CHECK		CONFIG_RCU_CPU_STALL_TIMEOUT

	This macro defines the period of time that RCU will wait from		This kernel configuration parameter defines the period of time
	the beginning of a grace period until it issues an RCU CPU		that RCU will wait from the beginning of a grace period until it
	stall warning. This time period is normally ten seconds.		issues an RCU CPU stall warning. This time period is normally
			ten seconds.

	RCU_SECONDS_TILL_STALL_RECHECK		RCU_SECONDS_TILL_STALL_RECHECK

	This macro defines the period of time that RCU will wait after		This macro defines the period of time that RCU will wait after
	issuing a stall warning until it issues another stall warning		issuing a stall warning until it issues another stall warning
	for the same stall. This time period is normally set to thirty		for the same stall. This time period is normally set to three
	seconds.		times the check interval plus thirty seconds.

	RCU_STALL_RAT_DELAY		RCU_STALL_RAT_DELAY

Documentation/RCU/trace.txt

+236 −59

Original line number	Original line	Diff line number	Diff line
	@@ -10,34 +10,46 @@ for rcutree and next for rcutiny.

	CONFIG_TREE_RCU and CONFIG_TREE_PREEMPT_RCU debugfs Files and Formats		CONFIG_TREE_RCU and CONFIG_TREE_PREEMPT_RCU debugfs Files and Formats

	These implementations of RCU provides five debugfs files under the		These implementations of RCU provides several debugfs files under the
	top-level directory RCU: rcu/rcudata (which displays fields in struct		top-level directory "rcu":
	rcu_data), rcu/rcudata.csv (which is a .csv spreadsheet version of
	rcu/rcudata), rcu/rcugp (which displays grace-period counters),		rcu/rcudata:
	rcu/rcuhier (which displays the struct rcu_node hierarchy), and		Displays fields in struct rcu_data.
	rcu/rcu_pending (which displays counts of the reasons that the		rcu/rcudata.csv:
	rcu_pending() function decided that there was core RCU work to do).		Comma-separated values spreadsheet version of rcudata.
			rcu/rcugp:
			Displays grace-period counters.
			rcu/rcuhier:
			Displays the struct rcu_node hierarchy.
			rcu/rcu_pending:
			Displays counts of the reasons rcu_pending() decided that RCU had
			work to do.
			rcu/rcutorture:
			Displays rcutorture test progress.
			rcu/rcuboost:
			Displays RCU boosting statistics. Only present if
			CONFIG_RCU_BOOST=y.

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

	rcu_sched:		rcu_sched:
	0 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=10951/1 dn=0 df=1101 of=0 ri=36 ql=0 b=10		0 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=545/1/0 df=50 of=0 ri=0 ql=163 qs=NRW. kt=0/W/0 ktl=ebc3 b=10 ci=153737 co=0 ca=0
	1 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=16117/1 dn=0 df=1015 of=0 ri=0 ql=0 b=10		1 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=967/1/0 df=58 of=0 ri=0 ql=634 qs=NRW. kt=0/W/1 ktl=58c b=10 ci=191037 co=0 ca=0
	2 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=1445/1 dn=0 df=1839 of=0 ri=0 ql=0 b=10		2 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=1081/1/0 df=175 of=0 ri=0 ql=74 qs=N.W. kt=0/W/2 ktl=da94 b=10 ci=75991 co=0 ca=0
	3 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=6681/1 dn=0 df=1545 of=0 ri=0 ql=0 b=10		3 c=20942 g=20943 pq=1 pqc=20942 qp=1 dt=1846/0/0 df=404 of=0 ri=0 ql=0 qs=.... kt=0/W/3 ktl=d1cd b=10 ci=72261 co=0 ca=0
	4 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=1003/1 dn=0 df=1992 of=0 ri=0 ql=0 b=10		4 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=369/1/0 df=83 of=0 ri=0 ql=48 qs=N.W. kt=0/W/4 ktl=e0e7 b=10 ci=128365 co=0 ca=0
	5 c=17829 g=17830 pq=1 pqc=17829 qp=1 dt=3887/1 dn=0 df=3331 of=0 ri=4 ql=2 b=10		5 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=381/1/0 df=64 of=0 ri=0 ql=169 qs=NRW. kt=0/W/5 ktl=fb2f b=10 ci=164360 co=0 ca=0
	6 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=859/1 dn=0 df=3224 of=0 ri=0 ql=0 b=10		6 c=20972 g=20973 pq=1 pqc=20972 qp=0 dt=1037/1/0 df=183 of=0 ri=0 ql=62 qs=N.W. kt=0/W/6 ktl=d2ad b=10 ci=65663 co=0 ca=0
	7 c=17829 g=17830 pq=0 pqc=17829 qp=1 dt=3761/1 dn=0 df=1818 of=0 ri=0 ql=2 b=10		7 c=20897 g=20897 pq=1 pqc=20896 qp=0 dt=1572/0/0 df=382 of=0 ri=0 ql=0 qs=.... kt=0/W/7 ktl=cf15 b=10 ci=75006 co=0 ca=0
	rcu_bh:		rcu_bh:
	0 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=10951/1 dn=0 df=0 of=0 ri=0 ql=0 b=10		0 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=545/1/0 df=6 of=0 ri=1 ql=0 qs=.... kt=0/W/0 ktl=ebc3 b=10 ci=0 co=0 ca=0
	1 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=16117/1 dn=0 df=13 of=0 ri=0 ql=0 b=10		1 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=967/1/0 df=3 of=0 ri=1 ql=0 qs=.... kt=0/W/1 ktl=58c b=10 ci=151 co=0 ca=0
	2 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=1445/1 dn=0 df=15 of=0 ri=0 ql=0 b=10		2 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=1081/1/0 df=6 of=0 ri=1 ql=0 qs=.... kt=0/W/2 ktl=da94 b=10 ci=0 co=0 ca=0
	3 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=6681/1 dn=0 df=9 of=0 ri=0 ql=0 b=10		3 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=1846/0/0 df=8 of=0 ri=1 ql=0 qs=.... kt=0/W/3 ktl=d1cd b=10 ci=0 co=0 ca=0
	4 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=1003/1 dn=0 df=15 of=0 ri=0 ql=0 b=10		4 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=369/1/0 df=6 of=0 ri=1 ql=0 qs=.... kt=0/W/4 ktl=e0e7 b=10 ci=0 co=0 ca=0
	5 c=-275 g=-275 pq=1 pqc=-275 qp=0 dt=3887/1 dn=0 df=15 of=0 ri=0 ql=0 b=10		5 c=1480 g=1480 pq=1 pqc=1479 qp=0 dt=381/1/0 df=4 of=0 ri=1 ql=0 qs=.... kt=0/W/5 ktl=fb2f b=10 ci=0 co=0 ca=0
	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=1480 g=1480 pq=1 pqc=1479 qp=0 dt=1037/1/0 df=6 of=0 ri=1 ql=0 qs=.... kt=0/W/6 ktl=d2ad b=10 ci=0 co=0 ca=0
	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=1474 g=1474 pq=1 pqc=1473 qp=0 dt=1572/0/0 df=8 of=0 ri=1 ql=0 qs=.... kt=0/W/7 ktl=cf15 b=10 ci=0 co=0 ca=0

	The first section lists the rcu_data structures for rcu_sched, the second		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		for rcu_bh. Note that CONFIG_TREE_PREEMPT_RCU kernels will have an
	@@ -52,17 +64,18 @@ o The number at the beginning of each line is the CPU number.
	substantially larger than the number of actual CPUs.		substantially larger than the number of actual CPUs.

	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. Offlined CPUs and CPUs in dynticks idle mode may
	behind, for example, CPU 4 under "rcu_sched" above, which has		lag quite a ways behind, for example, CPU 6 under "rcu_sched"
	slept through the past 25 RCU grace periods. It is not unusual		above, which has been offline through not quite 40,000 RCU grace
	to see CPUs lagging by thousands of grace periods.		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		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, offlined CPUs and CPUs in dynticks idle mode
	If the "c" and "g" values are equal, this CPU has already		may lag behind. If the "c" and "g" values are equal, this CPU
	reported a quiescent state for the last RCU grace period that		has already reported a quiescent state for the last RCU grace
	it is aware of, otherwise, the CPU believes that it owes RCU a		period that it is aware of, otherwise, the CPU believes that it
	quiescent state.		owes RCU a quiescent state.

	o "pq" indicates that this CPU has passed through a quiescent state		o "pq" indicates that this CPU has passed through a quiescent state
	for the current grace period. It is possible for "pq" to be		for the current grace period. It is possible for "pq" to be
	@@ -81,22 +94,16 @@ o "pqc" indicates which grace period the last-observed quiescent
	the next grace period!		the next grace period!

	o "qp" indicates that RCU still expects a quiescent state from		o "qp" indicates that RCU still expects a quiescent state from
	this CPU.		this CPU. Offlined CPUs and CPUs in dyntick idle mode might
			well have qp=1, which is OK: RCU is still ignoring them.

	o "dt" is the current value of the dyntick counter that is incremented		o "dt" is the current value of the dyntick counter that is incremented
	when entering or leaving dynticks idle state, either by the		when entering or leaving dynticks idle state, either by the
	scheduler or by irq. The number after the "/" is the interrupt		scheduler or by irq. This number is even if the CPU is in
	nesting depth when in dyntick-idle state, or one greater than		dyntick idle mode and odd otherwise. The number after the first
	the interrupt-nesting depth otherwise.		"/" is the interrupt nesting depth when in dyntick-idle state,
			or one greater than the interrupt-nesting depth otherwise.
	This field is displayed only for CONFIG_NO_HZ kernels.		The number after the second "/" is the NMI nesting depth.

	o "dn" is the current value of the dyntick counter that is incremented
	when entering or leaving dynticks idle state via NMI. If both
	the "dt" and "dn" values are even, then this CPU is in dynticks
	idle mode and may be ignored by RCU. If either of these two
	counters is odd, then RCU must be alert to the possibility of
	an RCU read-side critical section running on this CPU.

	This field is displayed only for CONFIG_NO_HZ kernels.		This field is displayed only for CONFIG_NO_HZ kernels.

	@@ -108,7 +115,7 @@ o "df" is the number of times that some other CPU has forced a

	o "of" is the number of times that some other CPU has forced a		o "of" is the number of times that some other CPU has forced a
	quiescent state on behalf of this CPU due to this CPU being		quiescent state on behalf of this CPU due to this CPU being
	offline. In a perfect world, this might neve happen, but it		offline. In a perfect world, this might never happen, but it
	turns out that offlining and onlining a CPU can take several grace		turns out that offlining and onlining a CPU can take several grace
	periods, and so there is likely to be an extended period of time		periods, and so there is likely to be an extended period of time
	when RCU believes that the CPU is online when it really is not.		when RCU believes that the CPU is online when it really is not.
	@@ -125,6 +132,62 @@ o "ql" is the number of RCU callbacks currently residing on
	of what state they are in (new, waiting for grace period to		of what state they are in (new, waiting for grace period to
	start, waiting for grace period to end, ready to invoke).		start, waiting for grace period to end, ready to invoke).

			o "qs" gives an indication of the state of the callback queue
			with four characters:

			"N" Indicates that there are callbacks queued that are not
			ready to be handled by the next grace period, and thus
			will be handled by the grace period following the next
			one.

			"R" Indicates that there are callbacks queued that are
			ready to be handled by the next grace period.

			"W" Indicates that there are callbacks queued that are
			waiting on the current grace period.

			"D" Indicates that there are callbacks queued that have
			already been handled by a prior grace period, and are
			thus waiting to be invoked. Note that callbacks in
			the process of being invoked are not counted here.
			Callbacks in the process of being invoked are those
			that have been removed from the rcu_data structures
			queues by rcu_do_batch(), but which have not yet been
			invoked.

			If there are no callbacks in a given one of the above states,
			the corresponding character is replaced by ".".

			o "kt" is the per-CPU kernel-thread state. The digit preceding
			the first slash is zero if there is no work pending and 1
			otherwise. The character between the first pair of slashes is
			as follows:

			"S" The kernel thread is stopped, in other words, all
			CPUs corresponding to this rcu_node structure are
			offline.

			"R" The kernel thread is running.

			"W" The kernel thread is waiting because there is no work
			for it to do.

			"O" The kernel thread is waiting because it has been
			forced off of its designated CPU or because its
			->cpus_allowed mask permits it to run on other than
			its designated CPU.

			"Y" The kernel thread is yielding to avoid hogging CPU.

			"?" Unknown value, indicates a bug.

			The number after the final slash is the CPU that the kthread
			is actually running on.

			o "ktl" is the low-order 16 bits (in hexadecimal) of the count of
			the number of times that this CPU's per-CPU kthread has gone
			through its loop servicing invoke_rcu_cpu_kthread() requests.

	o "b" is the batch limit for this CPU. If more than this number		o "b" is the batch limit for this CPU. If more than this number
	of RCU callbacks is ready to invoke, then the remainder will		of RCU callbacks is ready to invoke, then the remainder will
	be deferred.		be deferred.
	@@ -174,14 +237,14 @@ o "gpnum" is the number of grace periods that have started. It is
	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
	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
	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_sched" and "rcu_bh" portions,		This is once again split into "rcu_sched" and "rcu_bh" portions,
	and CONFIG_TREE_PREEMPT_RCU kernels will again have an additional		and CONFIG_TREE_PREEMPT_RCU kernels will again have an additional
	@@ -240,13 +303,20 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
	current grace period.		current grace period.

	o The characters separated by the ">" indicate the state		o The characters separated by the ">" indicate the state
	of the blocked-tasks lists. A "T" preceding the ">"		of the blocked-tasks lists. A "G" preceding the ">"
	indicates that at least one task blocked in an RCU		indicates that at least one task blocked in an RCU
	read-side critical section blocks the current grace		read-side critical section blocks the current grace
	period, while a "." preceding the ">" indicates otherwise.		period, while a "E" preceding the ">" indicates that
	The character following the ">" indicates similarly for		at least one task blocked in an RCU read-side critical
	the next grace period. A "T" should appear in this		section blocks the current expedited grace period.
	field only for rcu-preempt.		A "T" character following the ">" indicates that at
			least one task is blocked within an RCU read-side
			critical section, regardless of whether any current
			grace period (expedited or normal) is inconvenienced.
			A "." character appears if the corresponding condition
			does not hold, so that "..>." indicates that no tasks
			are blocked. In contrast, "GE>T" indicates maximal
			inconvenience from blocked tasks.

	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
	@@ -328,6 +398,113 @@ o "nn" is the number of times that this CPU needed nothing. Alert
	is due to short-circuit evaluation in rcu_pending().		is due to short-circuit evaluation in rcu_pending().


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

			rcutorture test sequence: 0 (test in progress)
			rcutorture update version number: 615

			The first line shows the number of rcutorture tests that have completed
			since boot. If a test is currently running, the "(test in progress)"
			string will appear as shown above. The second line shows the number of
			update cycles that the current test has started, or zero if there is
			no test in progress.


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

			0:5 tasks=.... kt=W ntb=0 neb=0 nnb=0 j=2f95 bt=300f
			balk: nt=0 egt=989 bt=0 nb=0 ny=0 nos=16
			6:7 tasks=.... kt=W ntb=0 neb=0 nnb=0 j=2f95 bt=300f
			balk: nt=0 egt=225 bt=0 nb=0 ny=0 nos=6

			This information is output only for rcu_preempt. Each two-line entry
			corresponds to a leaf rcu_node strcuture. The fields are as follows:

			o "n:m" is the CPU-number range for the corresponding two-line
			entry. In the sample output above, the first entry covers
			CPUs zero through five and the second entry covers CPUs 6
			and 7.

			o "tasks=TNEB" gives the state of the various segments of the
			rnp->blocked_tasks list:

			"T" This indicates that there are some tasks that blocked
			while running on one of the corresponding CPUs while
			in an RCU read-side critical section.

			"N" This indicates that some of the blocked tasks are preventing
			the current normal (non-expedited) grace period from
			completing.

			"E" This indicates that some of the blocked tasks are preventing
			the current expedited grace period from completing.

			"B" This indicates that some of the blocked tasks are in
			need of RCU priority boosting.

			Each character is replaced with "." if the corresponding
			condition does not hold.

			o "kt" is the state of the RCU priority-boosting kernel
			thread associated with the corresponding rcu_node structure.
			The state can be one of the following:

			"S" The kernel thread is stopped, in other words, all
			CPUs corresponding to this rcu_node structure are
			offline.

			"R" The kernel thread is running.

			"W" The kernel thread is waiting because there is no work
			for it to do.

			"Y" The kernel thread is yielding to avoid hogging CPU.

			"?" Unknown value, indicates a bug.

			o "ntb" is the number of tasks boosted.

			o "neb" is the number of tasks boosted in order to complete an
			expedited grace period.

			o "nnb" is the number of tasks boosted in order to complete a
			normal (non-expedited) grace period. When boosting a task
			that was blocking both an expedited and a normal grace period,
			it is counted against the expedited total above.

			o "j" is the low-order 16 bits of the jiffies counter in
			hexadecimal.

			o "bt" is the low-order 16 bits of the value that the jiffies
			counter will have when we next start boosting, assuming that
			the current grace period does not end beforehand. This is
			also in hexadecimal.

			o "balk: nt" counts the number of times we didn't boost (in
			other words, we balked) even though it was time to boost because
			there were no blocked tasks to boost. This situation occurs
			when there is one blocked task on one rcu_node structure and
			none on some other rcu_node structure.

			o "egt" counts the number of times we balked because although
			there were blocked tasks, none of them were blocking the
			current grace period, whether expedited or otherwise.

			o "bt" counts the number of times we balked because boosting
			had already been initiated for the current grace period.

			o "nb" counts the number of times we balked because there
			was at least one task blocking the current non-expedited grace
			period that never had blocked. If it is already running, it
			just won't help to boost its priority!

			o "ny" counts the number of times we balked because it was
			not yet time to start boosting.

			o "nos" counts the number of times we balked for other
			reasons, e.g., the grace period ended first.


	CONFIG_TINY_RCU and CONFIG_TINY_PREEMPT_RCU debugfs Files and Formats		CONFIG_TINY_RCU and CONFIG_TINY_PREEMPT_RCU debugfs Files and Formats

	These implementations of RCU provides a single debugfs file under the		These implementations of RCU provides a single debugfs file under the
	@@ -394,9 +571,9 @@ o "neb" is the number of expedited grace periods that have had
	o "nnb" is the number of normal grace periods that have had		o "nnb" is the number of normal grace periods that have had
	to resort to RCU priority boosting since boot.		to resort to RCU priority boosting since boot.

	o "j" is the low-order 12 bits of the jiffies counter in hexadecimal.		o "j" is the low-order 16 bits of the jiffies counter in hexadecimal.

	o "bt" is the low-order 12 bits of the value that the jiffies counter		o "bt" is the low-order 16 bits of the value that the jiffies counter
	will have at the next time that boosting is scheduled to begin.		will have at the next time that boosting is scheduled to begin.

	o In the line beginning with "normal balk", the fields are as follows:		o In the line beginning with "normal balk", the fields are as follows:

Documentation/filesystems/proc.txt

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -836,7 +836,6 @@ Provides counts of softirq handlers serviced since boot time, for each cpu.
	TASKLET: 0 0 0 290		TASKLET: 0 0 0 290
	SCHED: 27035 26983 26971 26746		SCHED: 27035 26983 26971 26746
	HRTIMER: 0 0 0 0		HRTIMER: 0 0 0 0
	RCU: 1678 1769 2178 2250


	1.3 IDE devices in /proc/ide		1.3 IDE devices in /proc/ide

include/linux/interrupt.h

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -414,7 +414,6 @@ enum
	TASKLET_SOFTIRQ,		TASKLET_SOFTIRQ,
	SCHED_SOFTIRQ,		SCHED_SOFTIRQ,
	HRTIMER_SOFTIRQ,		HRTIMER_SOFTIRQ,
	RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */

	NR_SOFTIRQS		NR_SOFTIRQS
	};		};