Merge branches 'doc.2014.09.07a', 'fixes.2014.09.10a', 'nocb-nohz.2014.09.16b'...

Merge branches 'doc.2014.09.07a', 'fixes.2014.09.10a', 'nocb-nohz.2014.09.16b' and 'torture.2014.09.07a' into HEAD

doc.2014.09.07a: Documentation updates.
fixes.2014.09.10a: Miscellaneous fixes.
nocb-nohz.2014.09.16b: No-CBs CPUs and NO_HZ_FULL updates.
torture.2014.09.07a: Torture-test updates.

Documentation/kernel-parameters.txt

@@ -2881,6 +2881,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			Lazy RCU callbacks are those which RCU can
 			prove do nothing more than free memory.
 
+	rcutorture.cbflood_inter_holdoff= [KNL]
+			Set holdoff time (jiffies) between successive
+			callback-flood tests.
+
+	rcutorture.cbflood_intra_holdoff= [KNL]
+			Set holdoff time (jiffies) between successive
+			bursts of callbacks within a given callback-flood
+			test.
+
+	rcutorture.cbflood_n_burst= [KNL]
+			Set the number of bursts making up a given
+			callback-flood test.  Set this to zero to
+			disable callback-flood testing.
+
+	rcutorture.cbflood_n_per_burst= [KNL]
+			Set the number of callbacks to be registered
+			in a given burst of a callback-flood test.
+
 	rcutorture.fqs_duration= [KNL]
 			Set duration of force_quiescent_state bursts.
 

include/linux/rcupdate.h

@@ -269,6 +269,14 @@ static inline void rcu_user_hooks_switch(struct task_struct *prev,
 					 struct task_struct *next) { }
 #endif /* CONFIG_RCU_USER_QS */
 
+#ifdef CONFIG_RCU_NOCB_CPU
+void rcu_init_nohz(void);
+#else /* #ifdef CONFIG_RCU_NOCB_CPU */
+static inline void rcu_init_nohz(void)
+{
+}
+#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */
+
 /**
  * RCU_NONIDLE - Indicate idle-loop code that needs RCU readers
  * @a: Code that RCU needs to pay attention to.
@@ -349,7 +357,7 @@ bool rcu_lockdep_current_cpu_online(void);
 #else /* #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PROVE_RCU) */
 static inline bool rcu_lockdep_current_cpu_online(void)
 {
-	return 1;
+	return true;
 }
 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PROVE_RCU) */
 
@@ -371,41 +379,7 @@ extern struct lockdep_map rcu_sched_lock_map;
 extern struct lockdep_map rcu_callback_map;
 int debug_lockdep_rcu_enabled(void);
 
-/**
- * rcu_read_lock_held() - might we be in RCU read-side critical section?
- *
- * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an RCU
- * read-side critical section.  In absence of CONFIG_DEBUG_LOCK_ALLOC,
- * this assumes we are in an RCU read-side critical section unless it can
- * prove otherwise.  This is useful for debug checks in functions that
- * require that they be called within an RCU read-side critical section.
- *
- * Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
- * and while lockdep is disabled.
- *
- * Note that rcu_read_lock() and the matching rcu_read_unlock() must
- * occur in the same context, for example, it is illegal to invoke
- * rcu_read_unlock() in process context if the matching rcu_read_lock()
- * was invoked from within an irq handler.
- *
- * Note that rcu_read_lock() is disallowed if the CPU is either idle or
- * offline from an RCU perspective, so check for those as well.
- */
-static inline int rcu_read_lock_held(void)
-{
-	if (!debug_lockdep_rcu_enabled())
-		return 1;
-	if (!rcu_is_watching())
-		return 0;
-	if (!rcu_lockdep_current_cpu_online())
-		return 0;
-	return lock_is_held(&rcu_lock_map);
-}
-
-/*
- * rcu_read_lock_bh_held() is defined out of line to avoid #include-file
- * hell.
- */
+int rcu_read_lock_held(void);
 int rcu_read_lock_bh_held(void);
 
 /**

include/linux/torture.h

@@ -51,7 +51,7 @@
 
 /* Definitions for online/offline exerciser. */
 int torture_onoff_init(long ooholdoff, long oointerval);
-char *torture_onoff_stats(char *page);
+void torture_onoff_stats(void);
 bool torture_onoff_failures(void);
 
 /* Low-rider random number generator. */

include/trace/events/rcu.h

@@ -180,9 +180,12 @@ TRACE_EVENT(rcu_grace_period_init,
  * argument is a string as follows:
  *
  *	"WakeEmpty": Wake rcuo kthread, first CB to empty list.
+ *	"WakeEmptyIsDeferred": Wake rcuo kthread later, first CB to empty list.
  *	"WakeOvf": Wake rcuo kthread, CB list is huge.
+ *	"WakeOvfIsDeferred": Wake rcuo kthread later, CB list is huge.
  *	"WakeNot": Don't wake rcuo kthread.
  *	"WakeNotPoll": Don't wake rcuo kthread because it is polling.
+ *	"DeferredWake": Carried out the "IsDeferred" wakeup.
  *	"Poll": Start of new polling cycle for rcu_nocb_poll.
  *	"Sleep": Sleep waiting for CBs for !rcu_nocb_poll.
  *	"WokeEmpty": rcuo kthread woke to find empty list.

init/Kconfig

@@ -737,7 +737,7 @@ choice
 
 config RCU_NOCB_CPU_NONE
 	bool "No build_forced no-CBs CPUs"
-	depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
+	depends on RCU_NOCB_CPU
 	help
 	  This option does not force any of the CPUs to be no-CBs CPUs.
 	  Only CPUs designated by the rcu_nocbs= boot parameter will be
@@ -751,7 +751,7 @@ config RCU_NOCB_CPU_NONE
 
 config RCU_NOCB_CPU_ZERO
 	bool "CPU 0 is a build_forced no-CBs CPU"
-	depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
+	depends on RCU_NOCB_CPU
 	help
 	  This option forces CPU 0 to be a no-CBs CPU, so that its RCU
 	  callbacks are invoked by a per-CPU kthread whose name begins

init/main.c

@@ -578,6 +578,7 @@ asmlinkage __visible void __init start_kernel(void)
 	idr_init_cache();
 	rcu_init();
 	tick_nohz_init();
+	rcu_init_nohz();
 	context_tracking_init();
 	radix_tree_init();
 	/* init some links before init_ISA_irqs() */

kernel/rcu/tiny.c

@@ -51,7 +51,7 @@ static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
 
 #include "tiny_plugin.h"
 
-/* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
+/* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcu/tree.c. */
 static void rcu_idle_enter_common(long long newval)
 {
 	if (newval) {
@@ -62,7 +62,7 @@ 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)) {
+	if (IS_ENABLED(CONFIG_RCU_TRACE) && !is_idle_task(current)) {
 		struct task_struct *idle __maybe_unused = idle_task(smp_processor_id());
 
 		RCU_TRACE(trace_rcu_dyntick(TPS("Entry error: not idle task"),
@@ -114,7 +114,7 @@ void rcu_irq_exit(void)
 }
 EXPORT_SYMBOL_GPL(rcu_irq_exit);
 
-/* Common code for rcu_idle_exit() and rcu_irq_enter(), see kernel/rcutree.c. */
+/* Common code for rcu_idle_exit() and rcu_irq_enter(), see kernel/rcu/tree.c. */
 static void rcu_idle_exit_common(long long oldval)
 {
 	if (oldval) {
@@ -123,7 +123,7 @@ static void rcu_idle_exit_common(long long oldval)
 		return;
 	}
 	RCU_TRACE(trace_rcu_dyntick(TPS("End"), oldval, rcu_dynticks_nesting));
-	if (!is_idle_task(current)) {
+	if (IS_ENABLED(CONFIG_RCU_TRACE) && !is_idle_task(current)) {
 		struct task_struct *idle __maybe_unused = idle_task(smp_processor_id());
 
 		RCU_TRACE(trace_rcu_dyntick(TPS("Exit error: not idle task"),

kernel/rcu/tree.c

@@ -79,9 +79,18 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
  * the tracing userspace tools to be able to decipher the string
  * address to the matching string.
  */
-#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
+#ifdef CONFIG_TRACING
+# define DEFINE_RCU_TPS(sname) \
 static char sname##_varname[] = #sname; \
-static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \
+static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname;
+# define RCU_STATE_NAME(sname) sname##_varname
+#else
+# define DEFINE_RCU_TPS(sname)
+# define RCU_STATE_NAME(sname) __stringify(sname)
+#endif
+
+#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
+DEFINE_RCU_TPS(sname) \
 struct rcu_state sname##_state = { \
 	.level = { &sname##_state.node[0] }, \
 	.call = cr, \
@@ -93,7 +102,7 @@ struct rcu_state sname##_state = { \
 	.orphan_donetail = &sname##_state.orphan_donelist, \
 	.barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
 	.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
-	.name = sname##_varname, \
+	.name = RCU_STATE_NAME(sname), \
 	.abbr = sabbr, \
 }; \
 DEFINE_PER_CPU(struct rcu_data, sname##_data)
@@ -819,7 +828,7 @@ bool notrace __rcu_is_watching(void)
  */
 bool notrace rcu_is_watching(void)
 {
-	int ret;
+	bool ret;
 
 	preempt_disable();
 	ret = __rcu_is_watching();
@@ -1668,7 +1677,7 @@ static int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
 	if (fqs_state == RCU_SAVE_DYNTICK) {
 		/* Collect dyntick-idle snapshots. */
 		if (is_sysidle_rcu_state(rsp)) {
-			isidle = 1;
+			isidle = true;
 			maxj = jiffies - ULONG_MAX / 4;
 		}
 		force_qs_rnp(rsp, dyntick_save_progress_counter,
@@ -1677,14 +1686,15 @@ static int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
 		fqs_state = RCU_FORCE_QS;
 	} else {
 		/* Handle dyntick-idle and offline CPUs. */
-		isidle = 0;
+		isidle = false;
 		force_qs_rnp(rsp, rcu_implicit_dynticks_qs, &isidle, &maxj);
 	}
 	/* Clear flag to prevent immediate re-entry. */
 	if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
 		raw_spin_lock_irq(&rnp->lock);
 		smp_mb__after_unlock_lock();
-		ACCESS_ONCE(rsp->gp_flags) &= ~RCU_GP_FLAG_FQS;
+		ACCESS_ONCE(rsp->gp_flags) =
+			ACCESS_ONCE(rsp->gp_flags) & ~RCU_GP_FLAG_FQS;
 		raw_spin_unlock_irq(&rnp->lock);
 	}
 	return fqs_state;
@@ -1786,7 +1796,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
 			if (rcu_gp_init(rsp))
 				break;
 			cond_resched();
-			flush_signals(current);
+			WARN_ON(signal_pending(current));
 			trace_rcu_grace_period(rsp->name,
 					       ACCESS_ONCE(rsp->gpnum),
 					       TPS("reqwaitsig"));
@@ -1832,7 +1842,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
 			} else {
 				/* Deal with stray signal. */
 				cond_resched();
-				flush_signals(current);
+				WARN_ON(signal_pending(current));
 				trace_rcu_grace_period(rsp->name,
 						       ACCESS_ONCE(rsp->gpnum),
 						       TPS("fqswaitsig"));
@@ -1928,7 +1938,7 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
 {
 	WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
 	raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
-	wake_up(&rsp->gp_wq);  /* Memory barrier implied by wake_up() path. */
+	rcu_gp_kthread_wake(rsp);
 }
 
 /*
@@ -2210,8 +2220,6 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp)
 	/* Adjust any no-longer-needed kthreads. */
 	rcu_boost_kthread_setaffinity(rnp, -1);
 
-	/* Remove the dead CPU from the bitmasks in the rcu_node hierarchy. */
-
 	/* Exclude any attempts to start a new grace period. */
 	mutex_lock(&rsp->onoff_mutex);
 	raw_spin_lock_irqsave(&rsp->orphan_lock, flags);
@@ -2449,7 +2457,7 @@ static void force_qs_rnp(struct rcu_state *rsp,
 		for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
 			if ((rnp->qsmask & bit) != 0) {
 				if ((rnp->qsmaskinit & bit) != 0)
-					*isidle = 0;
+					*isidle = false;
 				if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj))
 					mask |= bit;
 			}
@@ -2505,9 +2513,10 @@ static void force_quiescent_state(struct rcu_state *rsp)
 		raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
 		return;  /* Someone beat us to it. */
 	}
-	ACCESS_ONCE(rsp->gp_flags) |= RCU_GP_FLAG_FQS;
+	ACCESS_ONCE(rsp->gp_flags) =
+		ACCESS_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS;
 	raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
-	wake_up(&rsp->gp_wq);  /* Memory barrier implied by wake_up() path. */
+	rcu_gp_kthread_wake(rsp);
 }
 
 /*
@@ -3442,6 +3451,7 @@ static int rcu_cpu_notify(struct notifier_block *self,
 	case CPU_UP_PREPARE_FROZEN:
 		rcu_prepare_cpu(cpu);
 		rcu_prepare_kthreads(cpu);
+		rcu_spawn_all_nocb_kthreads(cpu);
 		break;
 	case CPU_ONLINE:
 	case CPU_DOWN_FAILED:
@@ -3489,7 +3499,7 @@ static int rcu_pm_notify(struct notifier_block *self,
 }
 
 /*
- * Spawn the kthread that handles this RCU flavor's grace periods.
+ * Spawn the kthreads that handle each RCU flavor's grace periods.
  */
 static int __init rcu_spawn_gp_kthread(void)
 {
@@ -3498,6 +3508,7 @@ static int __init rcu_spawn_gp_kthread(void)
 	struct rcu_state *rsp;
 	struct task_struct *t;
 
+	rcu_scheduler_fully_active = 1;
 	for_each_rcu_flavor(rsp) {
 		t = kthread_run(rcu_gp_kthread, rsp, "%s", rsp->name);
 		BUG_ON(IS_ERR(t));
@@ -3505,8 +3516,9 @@ static int __init rcu_spawn_gp_kthread(void)
 		raw_spin_lock_irqsave(&rnp->lock, flags);
 		rsp->gp_kthread = t;
 		raw_spin_unlock_irqrestore(&rnp->lock, flags);
-		rcu_spawn_nocb_kthreads(rsp);
 	}
+	rcu_spawn_nocb_kthreads();
+	rcu_spawn_boost_kthreads();
 	return 0;
 }
 early_initcall(rcu_spawn_gp_kthread);

kernel/rcu/tree.h

@@ -350,7 +350,7 @@ struct rcu_data {
 	int nocb_p_count_lazy;		/*  (approximate). */
 	wait_queue_head_t nocb_wq;	/* For nocb kthreads to sleep on. */
 	struct task_struct *nocb_kthread;
-	bool nocb_defer_wakeup;		/* Defer wakeup of nocb_kthread. */
+	int nocb_defer_wakeup;		/* Defer wakeup of nocb_kthread. */
 
 	/* The following fields are used by the leader, hence own cacheline. */
 	struct rcu_head *nocb_gp_head ____cacheline_internodealigned_in_smp;
@@ -383,6 +383,11 @@ struct rcu_data {
 #define RCU_FORCE_QS		3	/* Need to force quiescent state. */
 #define RCU_SIGNAL_INIT		RCU_SAVE_DYNTICK
 
+/* Values for nocb_defer_wakeup field in struct rcu_data. */
+#define RCU_NOGP_WAKE_NOT	0
+#define RCU_NOGP_WAKE		1
+#define RCU_NOGP_WAKE_FORCE	2
+
 #define RCU_JIFFIES_TILL_FORCE_QS (1 + (HZ > 250) + (HZ > 500))
 					/* For jiffies_till_first_fqs and */
 					/*  and jiffies_till_next_fqs. */
@@ -572,6 +577,7 @@ static void rcu_preempt_do_callbacks(void);
 static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 						 struct rcu_node *rnp);
 #endif /* #ifdef CONFIG_RCU_BOOST */
+static void __init rcu_spawn_boost_kthreads(void);
 static void rcu_prepare_kthreads(int cpu);
 static void rcu_cleanup_after_idle(int cpu);
 static void rcu_prepare_for_idle(int cpu);
@@ -589,10 +595,14 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
 static bool rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp,
 				      struct rcu_data *rdp,
 				      unsigned long flags);
-static bool rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp);
+static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp);
 static void do_nocb_deferred_wakeup(struct rcu_data *rdp);
 static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp);
-static void rcu_spawn_nocb_kthreads(struct rcu_state *rsp);
+static void rcu_spawn_all_nocb_kthreads(int cpu);
+static void __init rcu_spawn_nocb_kthreads(void);
+#ifdef CONFIG_RCU_NOCB_CPU
+static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp);
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
 static void __maybe_unused rcu_kick_nohz_cpu(int cpu);
 static bool init_nocb_callback_list(struct rcu_data *rdp);
 static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq);

kernel/rcu/update.c

@@ -136,6 +136,38 @@ int notrace debug_lockdep_rcu_enabled(void)
 }
 EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
 
+/**
+ * rcu_read_lock_held() - might we be in RCU read-side critical section?
+ *
+ * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an RCU
+ * read-side critical section.  In absence of CONFIG_DEBUG_LOCK_ALLOC,
+ * this assumes we are in an RCU read-side critical section unless it can
+ * prove otherwise.  This is useful for debug checks in functions that
+ * require that they be called within an RCU read-side critical section.
+ *
+ * Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
+ * and while lockdep is disabled.
+ *
+ * Note that rcu_read_lock() and the matching rcu_read_unlock() must
+ * occur in the same context, for example, it is illegal to invoke
+ * rcu_read_unlock() in process context if the matching rcu_read_lock()
+ * was invoked from within an irq handler.
+ *
+ * Note that rcu_read_lock() is disallowed if the CPU is either idle or
+ * offline from an RCU perspective, so check for those as well.
+ */
+int rcu_read_lock_held(void)
+{
+	if (!debug_lockdep_rcu_enabled())
+		return 1;
+	if (!rcu_is_watching())
+		return 0;
+	if (!rcu_lockdep_current_cpu_online())
+		return 0;
+	return lock_is_held(&rcu_lock_map);
+}
+EXPORT_SYMBOL_GPL(rcu_read_lock_held);
+
 /**
  * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
  *

kernel/torture.c

@@ -211,18 +211,16 @@ EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
 /*
  * Print online/offline testing statistics.
  */
-char *torture_onoff_stats(char *page)
+void torture_onoff_stats(void)
 {
 #ifdef CONFIG_HOTPLUG_CPU
-	page += sprintf(page,
-		       "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
-		       n_online_successes, n_online_attempts,
-		       n_offline_successes, n_offline_attempts,
-		       min_online, max_online,
-		       min_offline, max_offline,
-		       sum_online, sum_offline, HZ);
+	pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
+		n_online_successes, n_online_attempts,
+		n_offline_successes, n_offline_attempts,
+		min_online, max_online,
+		min_offline, max_offline,
+		sum_online, sum_offline, HZ);
 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
-	return page;
 }
 EXPORT_SYMBOL_GPL(torture_onoff_stats);
 

tools/testing/selftests/rcutorture/bin/config2frag.sh

-#!/bin/sh
-# Usage: sh config2frag.sh < .config > configfrag
+#!/bin/bash
+# Usage: config2frag.sh < .config > configfrag
 #
 # Converts the "# CONFIG_XXX is not set" to "CONFIG_XXX=n" so that the
 # resulting file becomes a legitimate Kconfig fragment.

tools/testing/selftests/rcutorture/bin/configcheck.sh

-#!/bin/sh
-# Usage: sh configcheck.sh .config .config-template
+#!/bin/bash
+# Usage: configcheck.sh .config .config-template
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/configinit.sh

-#!/bin/sh
+#!/bin/bash
 #
-# sh configinit.sh config-spec-file [ build output dir ]
+# Usage: configinit.sh config-spec-file [ build output dir ]
 #
 # Create a .config file from the spec file.  Run from the kernel source tree.
 # Exits with 0 if all went well, with 1 if all went well but the config

tools/testing/selftests/rcutorture/bin/functions.sh

@@ -64,6 +64,26 @@ configfrag_boot_params () {
 	fi
 }
 
+# configfrag_boot_cpus bootparam-string config-fragment-file config-cpus
+#
+# Decreases number of CPUs based on any maxcpus= boot parameters specified.
+configfrag_boot_cpus () {
+	local bootargs="`configfrag_boot_params "$1" "$2"`"
+	local maxcpus
+	if echo "${bootargs}" | grep -q 'maxcpus=[0-9]'
+	then
+		maxcpus="`echo "${bootargs}" | sed -e 's/^.*maxcpus=\([0-9]*\).*$/\1/'`"
+		if test "$3" -gt "$maxcpus"
+		then
+			echo $maxcpus
+		else
+			echo $3
+		fi
+	else
+		echo $3
+	fi
+}
+
 # configfrag_hotplug_cpu config-fragment-file
 #
 # Returns 1 if the config fragment specifies hotplug CPU.

tools/testing/selftests/rcutorture/bin/kvm-build.sh

@@ -2,7 +2,7 @@
 #
 # Build a kvm-ready Linux kernel from the tree in the current directory.
 #
-# Usage: sh kvm-build.sh config-template build-dir more-configs
+# Usage: kvm-build.sh config-template build-dir more-configs
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/kvm-recheck-lock.sh

@@ -2,7 +2,7 @@
 #
 # Analyze a given results directory for locktorture progress.
 #
-# Usage: sh kvm-recheck-lock.sh resdir
+# Usage: kvm-recheck-lock.sh resdir
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh

@@ -2,7 +2,7 @@
 #
 # Analyze a given results directory for rcutorture progress.
 #
-# Usage: sh kvm-recheck-rcu.sh resdir
+# Usage: kvm-recheck-rcu.sh resdir
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/kvm-recheck.sh

@@ -4,7 +4,7 @@
 # check the build and console output for errors.  Given a directory
 # containing results directories, this recursively checks them all.
 #
-# Usage: sh kvm-recheck.sh resdir ...
+# Usage: kvm-recheck.sh resdir ...
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh

@@ -6,7 +6,7 @@
 # Execute this in the source tree.  Do not run it as a background task
 # because qemu does not seem to like that much.
 #
-# Usage: sh kvm-test-1-run.sh config builddir resdir minutes qemu-args boot_args
+# Usage: kvm-test-1-run.sh config builddir resdir minutes qemu-args boot_args
 #
 # qemu-args defaults to "-nographic", along with arguments specifying the
 #			number of CPUs and other options generated from
@@ -140,6 +140,7 @@ fi
 # Generate -smp qemu argument.
 qemu_args="-nographic $qemu_args"
 cpu_count=`configNR_CPUS.sh $config_template`
+cpu_count=`configfrag_boot_cpus "$boot_args" "$config_template" "$cpu_count"`
 vcpus=`identify_qemu_vcpus`
 if test $cpu_count -gt $vcpus
 then
@@ -214,7 +215,7 @@ then
 		fi
 		if test $kruntime -ge $((seconds + grace))
 		then
-			echo "!!! Hang at $kruntime vs. $seconds seconds" >> $resdir/Warnings 2>&1
+			echo "!!! PID $qemu_pid hung at $kruntime vs. $seconds seconds" >> $resdir/Warnings 2>&1
 			kill -KILL $qemu_pid
 			break
 		fi

tools/testing/selftests/rcutorture/bin/kvm.sh

@@ -7,7 +7,7 @@
 # Edit the definitions below to set the locations of the various directories,
 # as well as the test duration.
 #
-# Usage: sh kvm.sh [ options ]
+# Usage: kvm.sh [ options ]
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -188,7 +188,9 @@ for CF in $configs
 do
 	if test -f "$CONFIGFRAG/$kversion/$CF"
 	then
-		echo $CF `configNR_CPUS.sh $CONFIGFRAG/$kversion/$CF` >> $T/cfgcpu
+		cpu_count=`configNR_CPUS.sh $CONFIGFRAG/$kversion/$CF`
+		cpu_count=`configfrag_boot_cpus "$TORTURE_BOOTARGS" "$CONFIGFRAG/$kversion/$CF" "$cpu_count"`
+		echo $CF $cpu_count >> $T/cfgcpu
 	else
 		echo "The --configs file $CF does not exist, terminating."
 		exit 1

tools/testing/selftests/rcutorture/bin/parse-build.sh

-#!/bin/sh
+#!/bin/bash
 #
 # Check the build output from an rcutorture run for goodness.
 # The "file" is a pathname on the local system, and "title" is
@@ -6,8 +6,7 @@
 #
 # The file must contain kernel build output.
 #
-# Usage:
-#	sh parse-build.sh file title
+# Usage: parse-build.sh file title
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/bin/parse-console.sh

-#!/bin/sh
+#!/bin/bash
 #
 # Check the console output from an rcutorture run for oopses.
 # The "file" is a pathname on the local system, and "title" is
 # a text string for error-message purposes.
 #
-# Usage:
-#	sh parse-console.sh file title
+# Usage: parse-console.sh file title
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -33,6 +32,10 @@ title="$2"
 
 . functions.sh
 
+if grep -Pq '\x00' < $file
+then
+	print_warning Console output contains nul bytes, old qemu still running?
+fi
 egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:' < $file | grep -v 'ODEBUG: ' | grep -v 'Warning: unable to open an initial console' > $T
 if test -s $T
 then

tools/testing/selftests/rcutorture/bin/parse-torture.sh

-#!/bin/sh
+#!/bin/bash
 #
 # Check the console output from a torture run for goodness.
 # The "file" is a pathname on the local system, and "title" is
@@ -7,8 +7,7 @@
 # The file must contain torture output, but can be interspersed
 # with other dmesg text, as in console-log output.
 #
-# Usage:
-#	sh parse-torture.sh file title
+# Usage: parse-torture.sh file title
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

tools/testing/selftests/rcutorture/configs/rcu/TREE01

 CONFIG_SMP=y
-CONFIG_NR_CPUS=8
 CONFIG_PREEMPT_NONE=n
 CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y
@@ -10,8 +9,7 @@ CONFIG_NO_HZ_FULL=n
 CONFIG_RCU_FAST_NO_HZ=y
 CONFIG_RCU_TRACE=y
 CONFIG_HOTPLUG_CPU=y
-CONFIG_RCU_FANOUT=8
-CONFIG_RCU_FANOUT_EXACT=n
+CONFIG_MAXSMP=y
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_RCU_NOCB_CPU_ZERO=y
 CONFIG_DEBUG_LOCK_ALLOC=n

tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot

-rcutorture.torture_type=rcu_bh
+rcutorture.torture_type=rcu_bh maxcpus=8

tools/testing/selftests/rcutorture/configs/rcu/TREE07

 CONFIG_SMP=y
 CONFIG_NR_CPUS=16
+CONFIG_CPUMASK_OFFSTACK=y
 CONFIG_PREEMPT_NONE=y
 CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=n
@@ -7,7 +8,7 @@ CONFIG_PREEMPT=n
 CONFIG_HZ_PERIODIC=n
 CONFIG_NO_HZ_IDLE=n
 CONFIG_NO_HZ_FULL=y
-CONFIG_NO_HZ_FULL_ALL=y
+CONFIG_NO_HZ_FULL_ALL=n
 CONFIG_NO_HZ_FULL_SYSIDLE=y
 CONFIG_RCU_FAST_NO_HZ=n
 CONFIG_RCU_TRACE=y

tools/testing/selftests/rcutorture/configs/rcu/TREE07.boot

+nohz_full=2-9

tools/testing/selftests/rcutorture/doc/initrd.txt

@@ -6,6 +6,7 @@ this case.  There are probably much better ways of doing this.
 That said, here are the commands:
 
 ------------------------------------------------------------------------
+cd tools/testing/selftests/rcutorture
 zcat /initrd.img > /tmp/initrd.img.zcat
 mkdir initrd
 cd initrd