Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / rcutree.h

diff --git a/kernel/include/linux/rcutree.h b/kernel/include/linux/rcutree.h
new file mode 100644 (file)
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--- /dev/null
+++ b/kernel/include/linux/rcutree.h
@@ -0,0 +1,119 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Dipankar Sarma <dipankar@in.ibm.com>
+ *        Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
+ *
+ * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
+ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ *     Documentation/RCU
+ */
+
+#ifndef __LINUX_RCUTREE_H
+#define __LINUX_RCUTREE_H
+
+void rcu_note_context_switch(void);
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
+int rcu_needs_cpu(unsigned long *delta_jiffies);
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
+void rcu_cpu_stall_reset(void);
+
+/*
+ * Note a virtualization-based context switch.  This is simply a
+ * wrapper around rcu_note_context_switch(), which allows TINY_RCU
+ * to save a few bytes.
+ */
+static inline void rcu_virt_note_context_switch(int cpu)
+{
+       rcu_note_context_switch();
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define synchronize_rcu_bh    synchronize_rcu
+#else
+void synchronize_rcu_bh(void);
+#endif
+void synchronize_sched_expedited(void);
+void synchronize_rcu_expedited(void);
+
+void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
+
+/**
+ * synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period
+ *
+ * Wait for an RCU-bh grace period to elapse, but use a "big hammer"
+ * approach to force the grace period to end quickly.  This consumes
+ * significant time on all CPUs and is unfriendly to real-time workloads,
+ * so is thus not recommended for any sort of common-case code.  In fact,
+ * if you are using synchronize_rcu_bh_expedited() in a loop, please
+ * restructure your code to batch your updates, and then use a single
+ * synchronize_rcu_bh() instead.
+ *
+ * Note that it is illegal to call this function while holding any lock
+ * that is acquired by a CPU-hotplug notifier.  And yes, it is also illegal
+ * to call this function from a CPU-hotplug notifier.  Failing to observe
+ * these restriction will result in deadlock.
+ */
+static inline void synchronize_rcu_bh_expedited(void)
+{
+       synchronize_sched_expedited();
+}
+
+void rcu_barrier(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define rcu_barrier_bh                rcu_barrier
+#else
+void rcu_barrier_bh(void);
+#endif
+void rcu_barrier_sched(void);
+unsigned long get_state_synchronize_rcu(void);
+void cond_synchronize_rcu(unsigned long oldstate);
+
+extern unsigned long rcutorture_testseq;
+extern unsigned long rcutorture_vernum;
+unsigned long rcu_batches_started(void);
+unsigned long rcu_batches_started_bh(void);
+unsigned long rcu_batches_started_sched(void);
+unsigned long rcu_batches_completed(void);
+unsigned long rcu_batches_completed_sched(void);
+void show_rcu_gp_kthreads(void);
+
+void rcu_force_quiescent_state(void);
+void rcu_sched_force_quiescent_state(void);
+
+void exit_rcu(void);
+
+void rcu_scheduler_starting(void);
+extern int rcu_scheduler_active __read_mostly;
+
+bool rcu_is_watching(void);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+void rcu_bh_force_quiescent_state(void);
+unsigned long rcu_batches_completed_bh(void);
+#else
+# define rcu_bh_force_quiescent_state  rcu_force_quiescent_state
+# define rcu_batches_completed_bh      rcu_batches_completed
+#endif
+
+void rcu_all_qs(void);
+
+#endif /* __LINUX_RCUTREE_H */