#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
-#include <linux/wait-simple.h>
+#include <linux/swait.h>
+#include <linux/stop_machine.h>
/*
* Define shape of hierarchy based on NR_CPUS, CONFIG_RCU_FANOUT, and
* In practice, this did work well going from three levels to four.
* Of course, your mileage may vary.
*/
-#define MAX_RCU_LVLS 4
-#define RCU_FANOUT_1 (CONFIG_RCU_FANOUT_LEAF)
-#define RCU_FANOUT_2 (RCU_FANOUT_1 * CONFIG_RCU_FANOUT)
-#define RCU_FANOUT_3 (RCU_FANOUT_2 * CONFIG_RCU_FANOUT)
-#define RCU_FANOUT_4 (RCU_FANOUT_3 * CONFIG_RCU_FANOUT)
+
+#ifdef CONFIG_RCU_FANOUT
+#define RCU_FANOUT CONFIG_RCU_FANOUT
+#else /* #ifdef CONFIG_RCU_FANOUT */
+# ifdef CONFIG_64BIT
+# define RCU_FANOUT 64
+# else
+# define RCU_FANOUT 32
+# endif
+#endif /* #else #ifdef CONFIG_RCU_FANOUT */
+
+#ifdef CONFIG_RCU_FANOUT_LEAF
+#define RCU_FANOUT_LEAF CONFIG_RCU_FANOUT_LEAF
+#else /* #ifdef CONFIG_RCU_FANOUT_LEAF */
+# ifdef CONFIG_64BIT
+# define RCU_FANOUT_LEAF 64
+# else
+# define RCU_FANOUT_LEAF 32
+# endif
+#endif /* #else #ifdef CONFIG_RCU_FANOUT_LEAF */
+
+#define RCU_FANOUT_1 (RCU_FANOUT_LEAF)
+#define RCU_FANOUT_2 (RCU_FANOUT_1 * RCU_FANOUT)
+#define RCU_FANOUT_3 (RCU_FANOUT_2 * RCU_FANOUT)
+#define RCU_FANOUT_4 (RCU_FANOUT_3 * RCU_FANOUT)
#if NR_CPUS <= RCU_FANOUT_1
# define RCU_NUM_LVLS 1
# define NUM_RCU_LVL_0 1
-# define NUM_RCU_LVL_1 (NR_CPUS)
-# define NUM_RCU_LVL_2 0
-# define NUM_RCU_LVL_3 0
-# define NUM_RCU_LVL_4 0
+# define NUM_RCU_NODES NUM_RCU_LVL_0
+# define NUM_RCU_LVL_INIT { NUM_RCU_LVL_0 }
+# define RCU_NODE_NAME_INIT { "rcu_node_0" }
+# define RCU_FQS_NAME_INIT { "rcu_node_fqs_0" }
+# define RCU_EXP_NAME_INIT { "rcu_node_exp_0" }
#elif NR_CPUS <= RCU_FANOUT_2
# define RCU_NUM_LVLS 2
# define NUM_RCU_LVL_0 1
# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-# define NUM_RCU_LVL_2 (NR_CPUS)
-# define NUM_RCU_LVL_3 0
-# define NUM_RCU_LVL_4 0
+# define NUM_RCU_NODES (NUM_RCU_LVL_0 + NUM_RCU_LVL_1)
+# define NUM_RCU_LVL_INIT { NUM_RCU_LVL_0, NUM_RCU_LVL_1 }
+# define RCU_NODE_NAME_INIT { "rcu_node_0", "rcu_node_1" }
+# define RCU_FQS_NAME_INIT { "rcu_node_fqs_0", "rcu_node_fqs_1" }
+# define RCU_EXP_NAME_INIT { "rcu_node_exp_0", "rcu_node_exp_1" }
#elif NR_CPUS <= RCU_FANOUT_3
# define RCU_NUM_LVLS 3
# define NUM_RCU_LVL_0 1
# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2)
# define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-# define NUM_RCU_LVL_3 (NR_CPUS)
-# define NUM_RCU_LVL_4 0
+# define NUM_RCU_NODES (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2)
+# define NUM_RCU_LVL_INIT { NUM_RCU_LVL_0, NUM_RCU_LVL_1, NUM_RCU_LVL_2 }
+# define RCU_NODE_NAME_INIT { "rcu_node_0", "rcu_node_1", "rcu_node_2" }
+# define RCU_FQS_NAME_INIT { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2" }
+# define RCU_EXP_NAME_INIT { "rcu_node_exp_0", "rcu_node_exp_1", "rcu_node_exp_2" }
#elif NR_CPUS <= RCU_FANOUT_4
# define RCU_NUM_LVLS 4
# define NUM_RCU_LVL_0 1
# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_3)
# define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2)
# define NUM_RCU_LVL_3 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-# define NUM_RCU_LVL_4 (NR_CPUS)
+# define NUM_RCU_NODES (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)
+# define NUM_RCU_LVL_INIT { NUM_RCU_LVL_0, NUM_RCU_LVL_1, NUM_RCU_LVL_2, NUM_RCU_LVL_3 }
+# define RCU_NODE_NAME_INIT { "rcu_node_0", "rcu_node_1", "rcu_node_2", "rcu_node_3" }
+# define RCU_FQS_NAME_INIT { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2", "rcu_node_fqs_3" }
+# define RCU_EXP_NAME_INIT { "rcu_node_exp_0", "rcu_node_exp_1", "rcu_node_exp_2", "rcu_node_exp_3" }
#else
# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
#endif /* #if (NR_CPUS) <= RCU_FANOUT_1 */
-#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3 + NUM_RCU_LVL_4)
-#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)
-
extern int rcu_num_lvls;
extern int rcu_num_nodes;
/* an rcu_data structure, otherwise, each */
/* bit corresponds to a child rcu_node */
/* structure. */
- unsigned long expmask; /* Groups that have ->blkd_tasks */
- /* elements that need to drain to allow the */
- /* current expedited grace period to */
- /* complete (only for PREEMPT_RCU). */
unsigned long qsmaskinit;
- /* Per-GP initial value for qsmask & expmask. */
+ /* Per-GP initial value for qsmask. */
/* Initialized from ->qsmaskinitnext at the */
/* beginning of each grace period. */
unsigned long qsmaskinitnext;
/* Online CPUs for next grace period. */
+ unsigned long expmask; /* CPUs or groups that need to check in */
+ /* to allow the current expedited GP */
+ /* to complete. */
+ unsigned long expmaskinit;
+ /* Per-GP initial values for expmask. */
+ /* Initialized from ->expmaskinitnext at the */
+ /* beginning of each expedited GP. */
+ unsigned long expmaskinitnext;
+ /* Online CPUs for next expedited GP. */
unsigned long grpmask; /* Mask to apply to parent qsmask. */
/* Only one bit will be set in this mask. */
int grplo; /* lowest-numbered CPU or group here. */
/* if there is no such task. If there */
/* is no current expedited grace period, */
/* then there can cannot be any such task. */
-#ifdef CONFIG_RCU_BOOST
struct list_head *boost_tasks;
/* Pointer to first task that needs to be */
/* priority boosted, or NULL if no priority */
unsigned long n_balk_nos;
/* Refused to boost: not sure why, though. */
/* This can happen due to race conditions. */
-#endif /* #ifdef CONFIG_RCU_BOOST */
#ifdef CONFIG_RCU_NOCB_CPU
- struct swait_head nocb_gp_wq[2];
+ struct swait_queue_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
int need_future_gp[2];
/* Counts of upcoming no-CB GP requests. */
raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp;
+
+ struct mutex exp_funnel_mutex ____cacheline_internodealigned_in_smp;
} ____cacheline_internodealigned_in_smp;
/*
for ((rnp) = (rsp)->level[rcu_num_lvls - 1]; \
(rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++)
+/*
+ * Union to allow "aggregate OR" operation on the need for a quiescent
+ * state by the normal and expedited grace periods.
+ */
+union rcu_noqs {
+ struct {
+ u8 norm;
+ u8 exp;
+ } b; /* Bits. */
+ u16 s; /* Set of bits, aggregate OR here. */
+};
+
/* Index values for nxttail array in struct rcu_data. */
#define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */
#define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */
/* is aware of having started. */
unsigned long rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */
/* for rcu_all_qs() invocations. */
- bool passed_quiesce; /* User-mode/idle loop etc. */
- bool qs_pending; /* Core waits for quiesc state. */
+ union rcu_noqs cpu_no_qs; /* No QSes yet for this CPU. */
+ bool core_needs_qs; /* Core waits for quiesc state. */
bool beenonline; /* CPU online at least once. */
bool gpwrap; /* Possible gpnum/completed wrap. */
struct rcu_node *mynode; /* This CPU's leaf of hierarchy */
unsigned long grpmask; /* Mask to apply to leaf qsmask. */
-#ifdef CONFIG_RCU_CPU_STALL_INFO
unsigned long ticks_this_gp; /* The number of scheduling-clock */
/* ticks this CPU has handled */
/* during and after the last grace */
/* period it is aware of. */
-#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
/* 2) batch handling */
/*
/* 5) __rcu_pending() statistics. */
unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */
- unsigned long n_rp_qs_pending;
+ unsigned long n_rp_core_needs_qs;
unsigned long n_rp_report_qs;
unsigned long n_rp_cb_ready;
unsigned long n_rp_cpu_needs_gp;
unsigned long n_rp_nocb_defer_wakeup;
unsigned long n_rp_need_nothing;
- /* 6) _rcu_barrier() and OOM callbacks. */
+ /* 6) _rcu_barrier(), OOM callbacks, and expediting. */
struct rcu_head barrier_head;
#ifdef CONFIG_RCU_FAST_NO_HZ
struct rcu_head oom_head;
#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
+ struct mutex exp_funnel_mutex;
/* 7) Callback offloading. */
#ifdef CONFIG_RCU_NOCB_CPU
atomic_long_t nocb_q_count_lazy; /* invocation (all stages). */
struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */
struct rcu_head **nocb_follower_tail;
- struct swait_head nocb_wq; /* For nocb kthreads to sleep on. */
+ struct swait_queue_head nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
int nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
/* 8) RCU CPU stall data. */
-#ifdef CONFIG_RCU_CPU_STALL_INFO
unsigned int softirq_snap; /* Snapshot of softirq activity. */
-#endif /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
int cpu;
struct rcu_state *rsp;
};
-/* Values for fqs_state field in struct rcu_state. */
-#define RCU_GP_IDLE 0 /* No grace period in progress. */
-#define RCU_GP_INIT 1 /* Grace period being initialized. */
-#define RCU_SAVE_DYNTICK 2 /* Need to scan dyntick state. */
-#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
*/
struct rcu_state {
struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */
- struct rcu_node *level[RCU_NUM_LVLS]; /* Hierarchy levels. */
- u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */
- u8 levelspread[RCU_NUM_LVLS]; /* kids/node in each level. */
+ struct rcu_node *level[RCU_NUM_LVLS + 1];
+ /* Hierarchy levels (+1 to */
+ /* shut bogus gcc warning) */
u8 flavor_mask; /* bit in flavor mask. */
struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */
- void (*call)(struct rcu_head *head, /* call_rcu() flavor. */
- void (*func)(struct rcu_head *head));
+ call_rcu_func_t call; /* call_rcu() flavor. */
+ int ncpus; /* # CPUs seen so far. */
/* The following fields are guarded by the root rcu_node's lock. */
- u8 fqs_state ____cacheline_internodealigned_in_smp;
- /* Force QS state. */
- u8 boost; /* Subject to priority boost. */
+ u8 boost ____cacheline_internodealigned_in_smp;
+ /* Subject to priority boost. */
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
struct task_struct *gp_kthread; /* Task for grace periods. */
- struct swait_head gp_wq; /* Where GP task waits. */
+ struct swait_queue_head gp_wq; /* Where GP task waits. */
short gp_flags; /* Commands for GP task. */
short gp_state; /* GP kthread sleep state. */
struct mutex barrier_mutex; /* Guards barrier fields. */
atomic_t barrier_cpu_count; /* # CPUs waiting on. */
struct completion barrier_completion; /* Wake at barrier end. */
- unsigned long n_barrier_done; /* ++ at start and end of */
+ unsigned long barrier_sequence; /* ++ at start and end of */
/* _rcu_barrier(). */
/* End of fields guarded by barrier_mutex. */
- atomic_long_t expedited_start; /* Starting ticket. */
- atomic_long_t expedited_done; /* Done ticket. */
- atomic_long_t expedited_wrap; /* # near-wrap incidents. */
- atomic_long_t expedited_tryfail; /* # acquisition failures. */
+ unsigned long expedited_sequence; /* Take a ticket. */
+ atomic_long_t expedited_workdone0; /* # done by others #0. */
atomic_long_t expedited_workdone1; /* # done by others #1. */
atomic_long_t expedited_workdone2; /* # done by others #2. */
+ atomic_long_t expedited_workdone3; /* # done by others #3. */
atomic_long_t expedited_normal; /* # fallbacks to normal. */
- atomic_long_t expedited_stoppedcpus; /* # successful stop_cpus. */
- atomic_long_t expedited_done_tries; /* # tries to update _done. */
- atomic_long_t expedited_done_lost; /* # times beaten to _done. */
- atomic_long_t expedited_done_exit; /* # times exited _done loop. */
+ atomic_t expedited_need_qs; /* # CPUs left to check in. */
+ struct swait_queue_head expedited_wq; /* Wait for check-ins. */
+ int ncpus_snap; /* # CPUs seen last time. */
unsigned long jiffies_force_qs; /* Time at which to invoke */
/* force_quiescent_state(). */
#define RCU_GP_FLAG_INIT 0x1 /* Need grace-period initialization. */
#define RCU_GP_FLAG_FQS 0x2 /* Need grace-period quiescent-state forcing. */
-/* Values for rcu_state structure's gp_flags field. */
-#define RCU_GP_WAIT_INIT 0 /* Initial state. */
+/* Values for rcu_state structure's gp_state field. */
+#define RCU_GP_IDLE 0 /* Initial state and no GP in progress. */
#define RCU_GP_WAIT_GPS 1 /* Wait for grace-period start. */
-#define RCU_GP_WAIT_FQS 2 /* Wait for force-quiescent-state time. */
+#define RCU_GP_DONE_GPS 2 /* Wait done for grace-period start. */
+#define RCU_GP_WAIT_FQS 3 /* Wait for force-quiescent-state time. */
+#define RCU_GP_DOING_FQS 4 /* Wait done for force-quiescent-state time. */
+#define RCU_GP_CLEANUP 5 /* Grace-period cleanup started. */
+#define RCU_GP_CLEANED 6 /* Grace-period cleanup complete. */
extern struct list_head rcu_struct_flavors;
* RCU implementation internal declarations:
*/
extern struct rcu_state rcu_sched_state;
-DECLARE_PER_CPU(struct rcu_data, rcu_sched_data);
+#ifndef CONFIG_PREEMPT_RT_FULL
extern struct rcu_state rcu_bh_state;
-DECLARE_PER_CPU(struct rcu_data, rcu_bh_data);
+#endif
#ifdef CONFIG_PREEMPT_RCU
extern struct rcu_state rcu_preempt_state;
-DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
#endif /* #ifdef CONFIG_PREEMPT_RCU */
DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
static void rcu_print_detail_task_stall(struct rcu_state *rsp);
static int rcu_print_task_stall(struct rcu_node *rnp);
+static int rcu_print_task_exp_stall(struct rcu_node *rnp);
static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
static void rcu_preempt_check_callbacks(void);
-void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
+void call_rcu(struct rcu_head *head, rcu_callback_t func);
static void __init __rcu_init_preempt(void);
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
static void increment_cpu_stall_ticks(void);
static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu);
static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq);
-static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp);
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);
static void rcu_init_one_nocb(struct rcu_node *rnp);
static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
bool lazy, unsigned long flags);
#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */
}
#endif /* #ifdef CONFIG_RCU_TRACE */
+
+/*
+ * Place this after a lock-acquisition primitive to guarantee that
+ * an UNLOCK+LOCK pair act as a full barrier. This guarantee applies
+ * if the UNLOCK and LOCK are executed by the same CPU or if the
+ * UNLOCK and LOCK operate on the same lock variable.
+ */
+#ifdef CONFIG_PPC
+#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */
+#else /* #ifdef CONFIG_PPC */
+#define smp_mb__after_unlock_lock() do { } while (0)
+#endif /* #else #ifdef CONFIG_PPC */
Code Review / kvmfornfv.git / blobdiff