| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Paul E. McKenney | 1612 | 96.30% | 52 | 86.67% |
| Joel A Fernandes | 19 | 1.14% | 2 | 3.33% |
| Matthew Wilcox | 17 | 1.02% | 1 | 1.67% |
| Lai Jiangshan | 9 | 0.54% | 1 | 1.67% |
| Dmitriy Vyukov | 7 | 0.42% | 1 | 1.67% |
| Pranith Kumar | 6 | 0.36% | 1 | 1.67% |
| Paul Gortmaker | 3 | 0.18% | 1 | 1.67% |
| Steven Rostedt | 1 | 0.06% | 1 | 1.67% |
| Total | 1674 | 60 |
/* * Read-Copy Update definitions shared among RCU implementations. * * 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, 2011 * * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> */ #ifndef __LINUX_RCU_H #define __LINUX_RCU_H #include <trace/events/rcu.h> #ifdef CONFIG_RCU_TRACE #define RCU_TRACE(stmt) stmt #else /* #ifdef CONFIG_RCU_TRACE */ #define RCU_TRACE(stmt) #endif /* #else #ifdef CONFIG_RCU_TRACE */ /* Offset to allow for unmatched rcu_irq_{enter,exit}(). */ #define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1) /* * Grace-period counter management. */ #define RCU_SEQ_CTR_SHIFT 2 #define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1) /* * Return the counter portion of a sequence number previously returned * by rcu_seq_snap() or rcu_seq_current(). */ static inline unsigned long rcu_seq_ctr(unsigned long s) { return s >> RCU_SEQ_CTR_SHIFT; } /* * Return the state portion of a sequence number previously returned * by rcu_seq_snap() or rcu_seq_current(). */ static inline int rcu_seq_state(unsigned long s) { return s & RCU_SEQ_STATE_MASK; } /* * Set the state portion of the pointed-to sequence number. * The caller is responsible for preventing conflicting updates. */ static inline void rcu_seq_set_state(unsigned long *sp, int newstate) { WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK); WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate); } /* Adjust sequence number for start of update-side operation. */ static inline void rcu_seq_start(unsigned long *sp) { WRITE_ONCE(*sp, *sp + 1); smp_mb(); /* Ensure update-side operation after counter increment. */ WARN_ON_ONCE(rcu_seq_state(*sp) != 1); } /* Compute the end-of-grace-period value for the specified sequence number. */ static inline unsigned long rcu_seq_endval(unsigned long *sp) { return (*sp | RCU_SEQ_STATE_MASK) + 1; } /* Adjust sequence number for end of update-side operation. */ static inline void rcu_seq_end(unsigned long *sp) { smp_mb(); /* Ensure update-side operation before counter increment. */ WARN_ON_ONCE(!rcu_seq_state(*sp)); WRITE_ONCE(*sp, rcu_seq_endval(sp)); } /* * rcu_seq_snap - Take a snapshot of the update side's sequence number. * * This function returns the earliest value of the grace-period sequence number * that will indicate that a full grace period has elapsed since the current * time. Once the grace-period sequence number has reached this value, it will * be safe to invoke all callbacks that have been registered prior to the * current time. This value is the current grace-period number plus two to the * power of the number of low-order bits reserved for state, then rounded up to * the next value in which the state bits are all zero. */ static inline unsigned long rcu_seq_snap(unsigned long *sp) { unsigned long s; s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK; smp_mb(); /* Above access must not bleed into critical section. */ return s; } /* Return the current value the update side's sequence number, no ordering. */ static inline unsigned long rcu_seq_current(unsigned long *sp) { return READ_ONCE(*sp); } /* * Given a snapshot from rcu_seq_snap(), determine whether or not the * corresponding update-side operation has started. */ static inline bool rcu_seq_started(unsigned long *sp, unsigned long s) { return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp)); } /* * Given a snapshot from rcu_seq_snap(), determine whether or not a * full update-side operation has occurred. */ static inline bool rcu_seq_done(unsigned long *sp, unsigned long s) { return ULONG_CMP_GE(READ_ONCE(*sp), s); } /* * Has a grace period completed since the time the old gp_seq was collected? */ static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new) { return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK); } /* * Has a grace period started since the time the old gp_seq was collected? */ static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new) { return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK, new); } /* * Roughly how many full grace periods have elapsed between the collection * of the two specified grace periods? */ static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old) { unsigned long rnd_diff; if (old == new) return 0; /* * Compute the number of grace periods (still shifted up), plus * one if either of new and old is not an exact grace period. */ rnd_diff = (new & ~RCU_SEQ_STATE_MASK) - ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) + ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK)); if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff)) return 1; /* Definitely no grace period has elapsed. */ return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2; } /* * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally * by call_rcu() and rcu callback execution, and are therefore not part * of the RCU API. These are in rcupdate.h because they are used by all * RCU implementations. */ #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD # define STATE_RCU_HEAD_READY 0 # define STATE_RCU_HEAD_QUEUED 1 extern struct debug_obj_descr rcuhead_debug_descr; static inline int debug_rcu_head_queue(struct rcu_head *head) { int r1; r1 = debug_object_activate(head, &rcuhead_debug_descr); debug_object_active_state(head, &rcuhead_debug_descr, STATE_RCU_HEAD_READY, STATE_RCU_HEAD_QUEUED); return r1; } static inline void debug_rcu_head_unqueue(struct rcu_head *head) { debug_object_active_state(head, &rcuhead_debug_descr, STATE_RCU_HEAD_QUEUED, STATE_RCU_HEAD_READY); debug_object_deactivate(head, &rcuhead_debug_descr); } #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ static inline int debug_rcu_head_queue(struct rcu_head *head) { return 0; } static inline void debug_rcu_head_unqueue(struct rcu_head *head) { } #endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ void kfree(const void *); /* * Reclaim the specified callback, either by invoking it (non-lazy case) * or freeing it directly (lazy case). Return true if lazy, false otherwise. */ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head) { rcu_callback_t f; unsigned long offset = (unsigned long)head->func; rcu_lock_acquire(&rcu_callback_map); if (__is_kfree_rcu_offset(offset)) { RCU_TRACE(trace_rcu_invoke_kfree_callback(rn, head, offset);) kfree((void *)head - offset); rcu_lock_release(&rcu_callback_map); return true; } else { RCU_TRACE(trace_rcu_invoke_callback(rn, head);) f = head->func; WRITE_ONCE(head->func, (rcu_callback_t)0L); f(head); rcu_lock_release(&rcu_callback_map); return false; } } #ifdef CONFIG_RCU_STALL_COMMON extern int rcu_cpu_stall_suppress; int rcu_jiffies_till_stall_check(void); #define rcu_ftrace_dump_stall_suppress() \ do { \ if (!rcu_cpu_stall_suppress) \ rcu_cpu_stall_suppress = 3; \ } while (0) #define rcu_ftrace_dump_stall_unsuppress() \ do { \ if (rcu_cpu_stall_suppress == 3) \ rcu_cpu_stall_suppress = 0; \ } while (0) #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */ #define rcu_ftrace_dump_stall_suppress() #define rcu_ftrace_dump_stall_unsuppress() #endif /* #ifdef CONFIG_RCU_STALL_COMMON */ /* * Strings used in tracepoints need to be exported via the * tracing system such that tools like perf and trace-cmd can * translate the string address pointers to actual text. */ #define TPS(x) tracepoint_string(x) /* * Dump the ftrace buffer, but only one time per callsite per boot. */ #define rcu_ftrace_dump(oops_dump_mode) \ do { \ static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \ \ if (!atomic_read(&___rfd_beenhere) && \ !atomic_xchg(&___rfd_beenhere, 1)) { \ tracing_off(); \ rcu_ftrace_dump_stall_suppress(); \ ftrace_dump(oops_dump_mode); \ rcu_ftrace_dump_stall_unsuppress(); \ } \ } while (0) void rcu_early_boot_tests(void); void rcu_test_sync_prims(void); /* * This function really isn't for public consumption, but RCU is special in * that context switches can allow the state machine to make progress. */ extern void resched_cpu(int cpu); #if defined(SRCU) || !defined(TINY_RCU) #include <linux/rcu_node_tree.h> extern int rcu_num_lvls; extern int num_rcu_lvl[]; extern int rcu_num_nodes; static bool rcu_fanout_exact; static int rcu_fanout_leaf; /* * Compute the per-level fanout, either using the exact fanout specified * or balancing the tree, depending on the rcu_fanout_exact boot parameter. */ static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt) { int i; if (rcu_fanout_exact) { levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf; for (i = rcu_num_lvls - 2; i >= 0; i--) levelspread[i] = RCU_FANOUT; } else { int ccur; int cprv; cprv = nr_cpu_ids; for (i = rcu_num_lvls - 1; i >= 0; i--) { ccur = levelcnt[i]; levelspread[i] = (cprv + ccur - 1) / ccur; cprv = ccur; } } } /* Returns a pointer to the first leaf rcu_node structure. */ #define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1]) /* Is this rcu_node a leaf? */ #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1) /* Is this rcu_node the last leaf? */ #define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1]) /* * Do a full breadth-first scan of the {s,}rcu_node structures for the * specified state structure (for SRCU) or the only rcu_state structure * (for RCU). */ #define srcu_for_each_node_breadth_first(sp, rnp) \ for ((rnp) = &(sp)->node[0]; \ (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++) #define rcu_for_each_node_breadth_first(rnp) \ srcu_for_each_node_breadth_first(&rcu_state, rnp) /* * Scan the leaves of the rcu_node hierarchy for the rcu_state structure. * Note that if there is a singleton rcu_node tree with but one rcu_node * structure, this loop -will- visit the rcu_node structure. It is still * a leaf node, even if it is also the root node. */ #define rcu_for_each_leaf_node(rnp) \ for ((rnp) = rcu_first_leaf_node(); \ (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++) /* * Iterate over all possible CPUs in a leaf RCU node. */ #define for_each_leaf_node_possible_cpu(rnp, cpu) \ for ((cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \ (cpu) <= rnp->grphi; \ (cpu) = cpumask_next((cpu), cpu_possible_mask)) /* * Iterate over all CPUs in a leaf RCU node's specified mask. */ #define rcu_find_next_bit(rnp, cpu, mask) \ ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu))) #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \ for ((cpu) = rcu_find_next_bit((rnp), 0, (mask)); \ (cpu) <= rnp->grphi; \ (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask))) /* * Wrappers for the rcu_node::lock acquire and release. * * Because the rcu_nodes form a tree, the tree traversal locking will observe * different lock values, this in turn means that an UNLOCK of one level * followed by a LOCK of another level does not imply a full memory barrier; * and most importantly transitivity is lost. * * In order to restore full ordering between tree levels, augment the regular * lock acquire functions with smp_mb__after_unlock_lock(). * * As ->lock of struct rcu_node is a __private field, therefore one should use * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. */ #define raw_spin_lock_rcu_node(p) \ do { \ raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ smp_mb__after_unlock_lock(); \ } while (0) #define raw_spin_unlock_rcu_node(p) raw_spin_unlock(&ACCESS_PRIVATE(p, lock)) #define raw_spin_lock_irq_rcu_node(p) \ do { \ raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ smp_mb__after_unlock_lock(); \ } while (0) #define raw_spin_unlock_irq_rcu_node(p) \ raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)) #define raw_spin_lock_irqsave_rcu_node(p, flags) \ do { \ raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ smp_mb__after_unlock_lock(); \ } while (0) #define raw_spin_unlock_irqrestore_rcu_node(p, flags) \ raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags) #define raw_spin_trylock_rcu_node(p) \ ({ \ bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ \ if (___locked) \ smp_mb__after_unlock_lock(); \ ___locked; \ }) #define raw_lockdep_assert_held_rcu_node(p) \ lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) #endif /* #if defined(SRCU) || !defined(TINY_RCU) */ #ifdef CONFIG_SRCU void srcu_init(void); #else /* #ifdef CONFIG_SRCU */ static inline void srcu_init(void) { } #endif /* #else #ifdef CONFIG_SRCU */ #ifdef CONFIG_TINY_RCU /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ static inline bool rcu_gp_is_normal(void) { return true; } static inline bool rcu_gp_is_expedited(void) { return false; } static inline void rcu_expedite_gp(void) { } static inline void rcu_unexpedite_gp(void) { } static inline void rcu_request_urgent_qs_task(struct task_struct *t) { } #else /* #ifdef CONFIG_TINY_RCU */ bool rcu_gp_is_normal(void); /* Internal RCU use. */ bool rcu_gp_is_expedited(void); /* Internal RCU use. */ void rcu_expedite_gp(void); void rcu_unexpedite_gp(void); void rcupdate_announce_bootup_oddness(void); void rcu_request_urgent_qs_task(struct task_struct *t); #endif /* #else #ifdef CONFIG_TINY_RCU */ #define RCU_SCHEDULER_INACTIVE 0 #define RCU_SCHEDULER_INIT 1 #define RCU_SCHEDULER_RUNNING 2 enum rcutorture_type { RCU_FLAVOR, RCU_BH_FLAVOR, RCU_SCHED_FLAVOR, RCU_TASKS_FLAVOR, SRCU_FLAVOR, INVALID_RCU_FLAVOR }; #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU) void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, unsigned long *gp_seq); void rcutorture_record_progress(unsigned long vernum); void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp, unsigned long secs, unsigned long c_old, unsigned long c); #else static inline void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, unsigned long *gp_seq) { *flags = 0; *gp_seq = 0; } static inline void rcutorture_record_progress(unsigned long vernum) { } #ifdef CONFIG_RCU_TRACE void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp, unsigned long secs, unsigned long c_old, unsigned long c); #else #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ do { } while (0) #endif #endif #ifdef CONFIG_TINY_SRCU static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, struct srcu_struct *sp, int *flags, unsigned long *gp_seq) { if (test_type != SRCU_FLAVOR) return; *flags = 0; *gp_seq = sp->srcu_idx; } #elif defined(CONFIG_TREE_SRCU) void srcutorture_get_gp_data(enum rcutorture_type test_type, struct srcu_struct *sp, int *flags, unsigned long *gp_seq); #endif #ifdef CONFIG_TINY_RCU static inline unsigned long rcu_get_gp_seq(void) { return 0; } static inline unsigned long rcu_exp_batches_completed(void) { return 0; } static inline unsigned long srcu_batches_completed(struct srcu_struct *sp) { return 0; } static inline void rcu_force_quiescent_state(void) { } static inline void show_rcu_gp_kthreads(void) { } static inline int rcu_get_gp_kthreads_prio(void) { return 0; } #else /* #ifdef CONFIG_TINY_RCU */ unsigned long rcu_get_gp_seq(void); unsigned long rcu_exp_batches_completed(void); unsigned long srcu_batches_completed(struct srcu_struct *sp); void show_rcu_gp_kthreads(void); int rcu_get_gp_kthreads_prio(void); void rcu_force_quiescent_state(void); extern struct workqueue_struct *rcu_gp_wq; extern struct workqueue_struct *rcu_par_gp_wq; #endif /* #else #ifdef CONFIG_TINY_RCU */ #ifdef CONFIG_RCU_NOCB_CPU bool rcu_is_nocb_cpu(int cpu); #else static inline bool rcu_is_nocb_cpu(int cpu) { return false; } #endif #endif /* __LINUX_RCU_H */
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