[PATCH rcu 0/3] Documentation updates for v6.5

[PATCH rcu 0/3] Documentation updates for v6.5

[Paul E. McKenney]

Hello!

This series contains documentation updates:

1.	Get rcutree module parameters back into alpha order.

2.	Document the rcutree.rcu_resched_ns module parameter.

3.	MAINTAINERS: Update qiang1.zhang@intel.com to
	qiang.zhang1211@gmail.com, courtesy of Zqiang.

						Thanx, Paul

------------------------------------------------------------------------

 Documentation/admin-guide/kernel-parameters.txt   |    7 +
 b/Documentation/admin-guide/kernel-parameters.txt |  120 +++++++++++-----------
 b/MAINTAINERS                                     |    2 
 3 files changed, 68 insertions(+), 61 deletions(-)

[PATCH rcu 1/3] doc: Get rcutree module parameters back into alpha order

[Paul E. McKenney]

This commit puts the rcutree module parameters back into proper
alphabetical order.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../admin-guide/kernel-parameters.txt         | 120 +++++++++---------
 1 file changed, 60 insertions(+), 60 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9e5bab29685f..8a094e2fc381 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4736,43 +4736,6 @@
 			the propagation of recent CPU-hotplug changes up
 			the rcu_node combining tree.
 
-	rcutree.use_softirq=	[KNL]
-			If set to zero, move all RCU_SOFTIRQ processing to
-			per-CPU rcuc kthreads.  Defaults to a non-zero
-			value, meaning that RCU_SOFTIRQ is used by default.
-			Specify rcutree.use_softirq=0 to use rcuc kthreads.
-
-			But note that CONFIG_PREEMPT_RT=y kernels disable
-			this kernel boot parameter, forcibly setting it
-			to zero.
-
-	rcutree.rcu_fanout_exact= [KNL]
-			Disable autobalancing of the rcu_node combining
-			tree.  This is used by rcutorture, and might
-			possibly be useful for architectures having high
-			cache-to-cache transfer latencies.
-
-	rcutree.rcu_fanout_leaf= [KNL]
-			Change the number of CPUs assigned to each
-			leaf rcu_node structure.  Useful for very
-			large systems, which will choose the value 64,
-			and for NUMA systems with large remote-access
-			latencies, which will choose a value aligned
-			with the appropriate hardware boundaries.
-
-	rcutree.rcu_min_cached_objs= [KNL]
-			Minimum number of objects which are cached and
-			maintained per one CPU. Object size is equal
-			to PAGE_SIZE. The cache allows to reduce the
-			pressure to page allocator, also it makes the
-			whole algorithm to behave better in low memory
-			condition.
-
-	rcutree.rcu_delay_page_cache_fill_msec= [KNL]
-			Set the page-cache refill delay (in milliseconds)
-			in response to low-memory conditions.  The range
-			of permitted values is in the range 0:100000.
-
 	rcutree.jiffies_till_first_fqs= [KNL]
 			Set delay from grace-period initialization to
 			first attempt to force quiescent states.
@@ -4811,21 +4774,6 @@
 			When RCU_NOCB_CPU is set, also adjust the
 			priority of NOCB callback kthreads.
 
-	rcutree.rcu_divisor= [KNL]
-			Set the shift-right count to use to compute
-			the callback-invocation batch limit bl from
-			the number of callbacks queued on this CPU.
-			The result will be bounded below by the value of
-			the rcutree.blimit kernel parameter.  Every bl
-			callbacks, the softirq handler will exit in
-			order to allow the CPU to do other work.
-
-			Please note that this callback-invocation batch
-			limit applies only to non-offloaded callback
-			invocation.  Offloaded callbacks are instead
-			invoked in the context of an rcuoc kthread, which
-			scheduler will preempt as it does any other task.
-
 	rcutree.nocb_nobypass_lim_per_jiffy= [KNL]
 			On callback-offloaded (rcu_nocbs) CPUs,
 			RCU reduces the lock contention that would
@@ -4839,14 +4787,6 @@
 			the ->nocb_bypass queue.  The definition of "too
 			many" is supplied by this kernel boot parameter.
 
-	rcutree.rcu_nocb_gp_stride= [KNL]
-			Set the number of NOCB callback kthreads in
-			each group, which defaults to the square root
-			of the number of CPUs.	Larger numbers reduce
-			the wakeup overhead on the global grace-period
-			kthread, but increases that same overhead on
-			each group's NOCB grace-period kthread.
-
 	rcutree.qhimark= [KNL]
 			Set threshold of queued RCU callbacks beyond which
 			batch limiting is disabled.
@@ -4864,6 +4804,56 @@
 			on rcutree.qhimark at boot time and to zero to
 			disable more aggressive help enlistment.
 
+	rcutree.rcu_delay_page_cache_fill_msec= [KNL]
+			Set the page-cache refill delay (in milliseconds)
+			in response to low-memory conditions.  The range
+			of permitted values is in the range 0:100000.
+
+	rcutree.rcu_divisor= [KNL]
+			Set the shift-right count to use to compute
+			the callback-invocation batch limit bl from
+			the number of callbacks queued on this CPU.
+			The result will be bounded below by the value of
+			the rcutree.blimit kernel parameter.  Every bl
+			callbacks, the softirq handler will exit in
+			order to allow the CPU to do other work.
+
+			Please note that this callback-invocation batch
+			limit applies only to non-offloaded callback
+			invocation.  Offloaded callbacks are instead
+			invoked in the context of an rcuoc kthread, which
+			scheduler will preempt as it does any other task.
+
+	rcutree.rcu_fanout_exact= [KNL]
+			Disable autobalancing of the rcu_node combining
+			tree.  This is used by rcutorture, and might
+			possibly be useful for architectures having high
+			cache-to-cache transfer latencies.
+
+	rcutree.rcu_fanout_leaf= [KNL]
+			Change the number of CPUs assigned to each
+			leaf rcu_node structure.  Useful for very
+			large systems, which will choose the value 64,
+			and for NUMA systems with large remote-access
+			latencies, which will choose a value aligned
+			with the appropriate hardware boundaries.
+
+	rcutree.rcu_min_cached_objs= [KNL]
+			Minimum number of objects which are cached and
+			maintained per one CPU. Object size is equal
+			to PAGE_SIZE. The cache allows to reduce the
+			pressure to page allocator, also it makes the
+			whole algorithm to behave better in low memory
+			condition.
+
+	rcutree.rcu_nocb_gp_stride= [KNL]
+			Set the number of NOCB callback kthreads in
+			each group, which defaults to the square root
+			of the number of CPUs.	Larger numbers reduce
+			the wakeup overhead on the global grace-period
+			kthread, but increases that same overhead on
+			each group's NOCB grace-period kthread.
+
 	rcutree.rcu_kick_kthreads= [KNL]
 			Cause the grace-period kthread to get an extra
 			wake_up() if it sleeps three times longer than
@@ -4885,6 +4875,16 @@
 			rcu_node tree with an eye towards determining
 			why a new grace period has not yet started.
 
+	rcutree.use_softirq=	[KNL]
+			If set to zero, move all RCU_SOFTIRQ processing to
+			per-CPU rcuc kthreads.  Defaults to a non-zero
+			value, meaning that RCU_SOFTIRQ is used by default.
+			Specify rcutree.use_softirq=0 to use rcuc kthreads.
+
+			But note that CONFIG_PREEMPT_RT=y kernels disable
+			this kernel boot parameter, forcibly setting it
+			to zero.
+
 	rcuscale.gp_async= [KNL]
 			Measure performance of asynchronous
 			grace-period primitives such as call_rcu().
-- 
2.40.1

[PATCH rcu 2/3] doc: Document the rcutree.rcu_resched_ns module parameter

[Paul E. McKenney]

This commit adds kernel-parameters.txt documentation for the
rcutree.rcu_resched_ns module parameter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8a094e2fc381..c21245c0cce6 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4861,6 +4861,13 @@
 			This wake_up() will be accompanied by a
 			WARN_ONCE() splat and an ftrace_dump().
 
+	rcutree.rcu_resched_ns= [KNL]
+			Limit the time spend invoking a batch of RCU
+			callbacks to the specified number of nanoseconds.
+			By default, this limit is checked only once
+			every 32 callbacks in order to limit the pain
+			inflicted by local_clock() overhead.
+
 	rcutree.rcu_unlock_delay= [KNL]
 			In CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels,
 			this specifies an rcu_read_unlock()-time delay
-- 
2.40.1

[PATCH rcu 3/3] MAINTAINERS: Update qiang1.zhang@intel.com to qiang.zhang1211@gmail.com

[Paul E. McKenney]

From: Zqiang <qiang1.zhang@intel.com>

The qiang1.zhang@intel.com email address will no longer be used, so this
commit updates to qiang.zhang1211@gmail.com.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 MAINTAINERS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 7e0b87d5aa2e..8af0aabe9bf5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17778,7 +17778,7 @@ M:	Boqun Feng <boqun.feng@gmail.com>
 R:	Steven Rostedt <rostedt@goodmis.org>
 R:	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 R:	Lai Jiangshan <jiangshanlai@gmail.com>
-R:	Zqiang <qiang1.zhang@intel.com>
+R:	Zqiang <qiang.zhang1211@gmail.com>
 L:	rcu@vger.kernel.org
 S:	Supported
 W:	http://www.rdrop.com/users/paulmck/RCU/
-- 
2.40.1