rcu: Move RCU-related source code to kernel/rcu directory

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>

Documentation/DocBook/device-drivers.tmpl

@@ -87,7 +87,10 @@ X!Iinclude/linux/kobject.h
 !Ekernel/printk/printk.c
 !Ekernel/panic.c
 !Ekernel/sys.c
-!Ekernel/rcupdate.c
+!Ekernel/rcu/srcu.c
+!Ekernel/rcu/tree.c
+!Ekernel/rcu/tree_plugin.h
+!Ekernel/rcu/update.c
      </sect1>
 
      <sect1><title>Device Resource Management</title>

Documentation/kernel-parameters.txt

@@ -2595,7 +2595,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	ramdisk_size=	[RAM] Sizes of RAM disks in kilobytes
 			See Documentation/blockdev/ramdisk.txt.
 
-	rcu_nocbs=	[KNL,BOOT]
+	rcu_nocbs=	[KNL]
 			In kernels built with CONFIG_RCU_NOCB_CPU=y, set
 			the specified list of CPUs to be no-callback CPUs.
 			Invocation of these CPUs' RCU callbacks will
@@ -2608,7 +2608,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			real-time workloads.  It can also improve energy
 			efficiency for asymmetric multiprocessors.
 
-	rcu_nocb_poll	[KNL,BOOT]
+	rcu_nocb_poll	[KNL]
 			Rather than requiring that offloaded CPUs
 			(specified by rcu_nocbs= above) explicitly
 			awaken the corresponding "rcuoN" kthreads,
@@ -2619,126 +2619,145 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			energy efficiency by requiring that the kthreads
 			periodically wake up to do the polling.
 
-	rcutree.blimit=	[KNL,BOOT]
+	rcutree.blimit=	[KNL]
 			Set maximum number of finished RCU callbacks to process
 			in one batch.
 
-	rcutree.fanout_leaf=	[KNL,BOOT]
+	rcutree.rcu_fanout_leaf= [KNL]
 			Increase the number of CPUs assigned to each
 			leaf rcu_node structure.  Useful for very large
 			systems.
 
-	rcutree.jiffies_till_first_fqs= [KNL,BOOT]
+	rcutree.jiffies_till_first_fqs= [KNL]
 			Set delay from grace-period initialization to
 			first attempt to force quiescent states.
 			Units are jiffies, minimum value is zero,
 			and maximum value is HZ.
 
-	rcutree.jiffies_till_next_fqs= [KNL,BOOT]
+	rcutree.jiffies_till_next_fqs= [KNL]
 			Set delay between subsequent attempts to force
 			quiescent states.  Units are jiffies, minimum
 			value is one, and maximum value is HZ.
 
-	rcutree.qhimark=	[KNL,BOOT]
+	rcutree.qhimark= [KNL]
 			Set threshold of queued
 			RCU callbacks over which batch limiting is disabled.
 
-	rcutree.qlowmark=	[KNL,BOOT]
+	rcutree.qlowmark= [KNL]
 			Set threshold of queued RCU callbacks below which
 			batch limiting is re-enabled.
 
-	rcutree.rcu_cpu_stall_suppress=	[KNL,BOOT]
-			Suppress RCU CPU stall warning messages.
-
-	rcutree.rcu_cpu_stall_timeout= [KNL,BOOT]
-			Set timeout for RCU CPU stall warning messages.
-
-	rcutree.rcu_idle_gp_delay=	[KNL,BOOT]
+	rcutree.rcu_idle_gp_delay= [KNL]
 			Set wakeup interval for idle CPUs that have
 			RCU callbacks (RCU_FAST_NO_HZ=y).
 
-	rcutree.rcu_idle_lazy_gp_delay=	[KNL,BOOT]
+	rcutree.rcu_idle_lazy_gp_delay= [KNL]
 			Set wakeup interval for idle CPUs that have
 			only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
 			Lazy RCU callbacks are those which RCU can
 			prove do nothing more than free memory.
 
-	rcutorture.fqs_duration= [KNL,BOOT]
+	rcutorture.fqs_duration= [KNL]
 			Set duration of force_quiescent_state bursts.
 
-	rcutorture.fqs_holdoff= [KNL,BOOT]
+	rcutorture.fqs_holdoff= [KNL]
 			Set holdoff time within force_quiescent_state bursts.
 
-	rcutorture.fqs_stutter= [KNL,BOOT]
+	rcutorture.fqs_stutter= [KNL]
 			Set wait time between force_quiescent_state bursts.
 
-	rcutorture.irqreader= [KNL,BOOT]
-			Test RCU readers from irq handlers.
+	rcutorture.gp_exp= [KNL]
+			Use expedited update-side primitives.
+
+	rcutorture.gp_normal= [KNL]
+			Use normal (non-expedited) update-side primitives.
+			If both gp_exp and gp_normal are set, do both.
+			If neither gp_exp nor gp_normal are set, still
+			do both.
 
-	rcutorture.n_barrier_cbs= [KNL,BOOT]
+	rcutorture.n_barrier_cbs= [KNL]
 			Set callbacks/threads for rcu_barrier() testing.
 
-	rcutorture.nfakewriters= [KNL,BOOT]
+	rcutorture.nfakewriters= [KNL]
 			Set number of concurrent RCU writers.  These just
 			stress RCU, they don't participate in the actual
 			test, hence the "fake".
 
-	rcutorture.nreaders= [KNL,BOOT]
+	rcutorture.nreaders= [KNL]
 			Set number of RCU readers.
 
-	rcutorture.onoff_holdoff= [KNL,BOOT]
+	rcutorture.object_debug= [KNL]
+			Enable debug-object double-call_rcu() testing.
+
+	rcutorture.onoff_holdoff= [KNL]
 			Set time (s) after boot for CPU-hotplug testing.
 
-	rcutorture.onoff_interval= [KNL,BOOT]
+	rcutorture.onoff_interval= [KNL]
 			Set time (s) between CPU-hotplug operations, or
 			zero to disable CPU-hotplug testing.
 
-	rcutorture.shuffle_interval= [KNL,BOOT]
+	rcutorture.rcutorture_runnable= [BOOT]
+			Start rcutorture running at boot time.
+
+	rcutorture.shuffle_interval= [KNL]
 			Set task-shuffle interval (s).  Shuffling tasks
 			allows some CPUs to go into dyntick-idle mode
 			during the rcutorture test.
 
-	rcutorture.shutdown_secs= [KNL,BOOT]
+	rcutorture.shutdown_secs= [KNL]
 			Set time (s) after boot system shutdown.  This
 			is useful for hands-off automated testing.
 
-	rcutorture.stall_cpu= [KNL,BOOT]
+	rcutorture.stall_cpu= [KNL]
 			Duration of CPU stall (s) to test RCU CPU stall
 			warnings, zero to disable.
 
-	rcutorture.stall_cpu_holdoff= [KNL,BOOT]
+	rcutorture.stall_cpu_holdoff= [KNL]
 			Time to wait (s) after boot before inducing stall.
 
-	rcutorture.stat_interval= [KNL,BOOT]
+	rcutorture.stat_interval= [KNL]
 			Time (s) between statistics printk()s.
 
-	rcutorture.stutter= [KNL,BOOT]
+	rcutorture.stutter= [KNL]
 			Time (s) to stutter testing, for example, specifying
 			five seconds causes the test to run for five seconds,
 			wait for five seconds, and so on.  This tests RCU's
 			ability to transition abruptly to and from idle.
 
-	rcutorture.test_boost= [KNL,BOOT]
+	rcutorture.test_boost= [KNL]
 			Test RCU priority boosting?  0=no, 1=maybe, 2=yes.
 			"Maybe" means test if the RCU implementation
 			under test support RCU priority boosting.
 
-	rcutorture.test_boost_duration= [KNL,BOOT]
+	rcutorture.test_boost_duration= [KNL]
 			Duration (s) of each individual boost test.
 
-	rcutorture.test_boost_interval= [KNL,BOOT]
+	rcutorture.test_boost_interval= [KNL]
 			Interval (s) between each boost test.
 
-	rcutorture.test_no_idle_hz= [KNL,BOOT]
+	rcutorture.test_no_idle_hz= [KNL]
 			Test RCU's dyntick-idle handling.  See also the
 			rcutorture.shuffle_interval parameter.
 
-	rcutorture.torture_type= [KNL,BOOT]
+	rcutorture.torture_type= [KNL]
 			Specify the RCU implementation to test.
 
-	rcutorture.verbose= [KNL,BOOT]
+	rcutorture.verbose= [KNL]
 			Enable additional printk() statements.
 
+	rcupdate.rcu_expedited= [KNL]
+			Use expedited grace-period primitives, for
+			example, synchronize_rcu_expedited() instead
+			of synchronize_rcu().  This reduces latency,
+			but can increase CPU utilization, degrade
+			real-time latency, and degrade energy efficiency.
+
+	rcupdate.rcu_cpu_stall_suppress= [KNL]
+			Suppress RCU CPU stall warning messages.
+
+	rcupdate.rcu_cpu_stall_timeout= [KNL]
+			Set timeout for RCU CPU stall warning messages.
+
 	rdinit=		[KNL]
 			Format: <full_path>
 			Run specified binary instead of /init from the ramdisk,

MAINTAINERS

@@ -6903,7 +6903,7 @@ M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
 F:	Documentation/RCU/torture.txt
-F:	kernel/rcutorture.c
+F:	kernel/rcu/torture.c
 
 RDC R-321X SoC
 M:	Florian Fainelli <florian@openwrt.org>
@@ -6930,8 +6930,9 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
 F:	Documentation/RCU/
 X:	Documentation/RCU/torture.txt
 F:	include/linux/rcu*
-F:	kernel/rcu*
-X:	kernel/rcutorture.c
+X:	include/linux/srcu.h
+F:	kernel/rcu/
+X:	kernel/rcu/torture.c
 
 REAL TIME CLOCK (RTC) SUBSYSTEM
 M:	Alessandro Zummo <a.zummo@towertech.it>
@@ -7618,8 +7619,8 @@ M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
 W:	http://www.rdrop.com/users/paulmck/RCU/
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
-F:	include/linux/srcu*
-F:	kernel/srcu*
+F:	include/linux/srcu.h
+F:	kernel/rcu/srcu.c
 
 SMACK SECURITY MODULE
 M:	Casey Schaufler <casey@schaufler-ca.com>

kernel/Makefile

@@ -6,9 +6,9 @@ obj-y     = fork.o exec_domain.o panic.o \
 	    cpu.o exit.o itimer.o time.o softirq.o resource.o \
 	    sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
 	    signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
-	    rcupdate.o extable.o params.o posix-timers.o \
+	    extable.o params.o posix-timers.o \
 	    kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
-	    hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
+	    hrtimer.o rwsem.o nsproxy.o semaphore.o \
 	    notifier.o ksysfs.o cred.o reboot.o \
 	    async.o range.o groups.o lglock.o smpboot.o
 
@@ -27,6 +27,7 @@ obj-y += power/
 obj-y += printk/
 obj-y += cpu/
 obj-y += irq/
+obj-y += rcu/
 
 obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
 obj-$(CONFIG_FREEZER) += freezer.o
@@ -81,12 +82,6 @@ obj-$(CONFIG_KGDB) += debug/
 obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
 obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
 obj-$(CONFIG_SECCOMP) += seccomp.o
-obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
-obj-$(CONFIG_TREE_RCU) += rcutree.o
-obj-$(CONFIG_TREE_PREEMPT_RCU) += rcutree.o
-obj-$(CONFIG_TREE_RCU_TRACE) += rcutree_trace.o
-obj-$(CONFIG_TINY_RCU) += rcutiny.o
-obj-$(CONFIG_TINY_PREEMPT_RCU) += rcutiny.o
 obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o

kernel/rcu/Makefile

@@ -0,0 +1,6 @@
+obj-y += update.o srcu.o
+obj-$(CONFIG_RCU_TORTURE_TEST) += torture.o
+obj-$(CONFIG_TREE_RCU) += tree.o
+obj-$(CONFIG_TREE_PREEMPT_RCU) += tree.o
+obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o
+obj-$(CONFIG_TINY_RCU) += tiny.o

kernel/rcutiny.c → kernel/rcu/tiny.c

@@ -43,7 +43,7 @@
 
 #include "rcu.h"
 
-/* Forward declarations for rcutiny_plugin.h. */
+/* Forward declarations for tiny_plugin.h. */
 struct rcu_ctrlblk;
 static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp);
 static void rcu_process_callbacks(struct softirq_action *unused);
@@ -53,7 +53,7 @@ static void __call_rcu(struct rcu_head *head,
 
 static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
 
-#include "rcutiny_plugin.h"
+#include "tiny_plugin.h"
 
 /* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
 static void rcu_idle_enter_common(long long newval)
@@ -67,7 +67,7 @@ static void rcu_idle_enter_common(long long newval)
 	RCU_TRACE(trace_rcu_dyntick(TPS("Start"),
 				    rcu_dynticks_nesting, newval));
 	if (!is_idle_task(current)) {
-		struct task_struct *idle = idle_task(smp_processor_id());
+		struct task_struct *idle __maybe_unused = idle_task(smp_processor_id());
 
 		RCU_TRACE(trace_rcu_dyntick(TPS("Entry error: not idle task"),
 					    rcu_dynticks_nesting, newval));
@@ -128,7 +128,7 @@ static void rcu_idle_exit_common(long long oldval)
 	}
 	RCU_TRACE(trace_rcu_dyntick(TPS("End"), oldval, rcu_dynticks_nesting));
 	if (!is_idle_task(current)) {
-		struct task_struct *idle = idle_task(smp_processor_id());
+		struct task_struct *idle __maybe_unused = idle_task(smp_processor_id());
 
 		RCU_TRACE(trace_rcu_dyntick(TPS("Exit error: not idle task"),
 			  oldval, rcu_dynticks_nesting));

kernel/rcutorture.c → kernel/rcu/torture.c

@@ -52,6 +52,12 @@
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
 
+MODULE_ALIAS("rcutorture");
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "rcutorture."
+
 static int fqs_duration;
 module_param(fqs_duration, int, 0444);
 MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us), 0 to disable");

kernel/rcutree.c → kernel/rcu/tree.c

@@ -41,6 +41,7 @@
 #include <linux/export.h>
 #include <linux/completion.h>
 #include <linux/moduleparam.h>
+#include <linux/module.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
@@ -56,11 +57,17 @@
 #include <linux/ftrace_event.h>
 #include <linux/suspend.h>
 
-#include "rcutree.h"
+#include "tree.h"
 #include <trace/events/rcu.h>
 
 #include "rcu.h"
 
+MODULE_ALIAS("rcutree");
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "rcutree."
+
 /* Data structures. */
 
 static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];
@@ -3298,7 +3305,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
 
 /*
  * Compute the rcu_node tree geometry from kernel parameters.  This cannot
- * replace the definitions in rcutree.h because those are needed to size
+ * replace the definitions in tree.h because those are needed to size
  * the ->node array in the rcu_state structure.
  */
 static void __init rcu_init_geometry(void)
@@ -3393,4 +3400,4 @@ void __init rcu_init(void)
 		rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
 }
 
-#include "rcutree_plugin.h"
+#include "tree_plugin.h"

kernel/rcutree_plugin.h → kernel/rcu/tree_plugin.h

@@ -28,7 +28,7 @@
 #include <linux/gfp.h>
 #include <linux/oom.h>
 #include <linux/smpboot.h>
-#include "time/tick-internal.h"
+#include "../time/tick-internal.h"
 
 #define RCU_KTHREAD_PRIO 1
 
@@ -1133,7 +1133,7 @@ void exit_rcu(void)
 
 #ifdef CONFIG_RCU_BOOST
 
-#include "rtmutex_common.h"
+#include "../rtmutex_common.h"
 
 #ifdef CONFIG_RCU_TRACE