ftrace: Add self-tests for multiple function trace users
[linux-2.6.git] / kernel / rcutree.h
index dc386a7..e8f057e 100644 (file)
 /*
  * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT.
  * In theory, it should be possible to add more levels straightforwardly.
- * In practice, this has not been tested, so there is probably some
- * bug somewhere.
+ * 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           (CONFIG_RCU_FANOUT)
-#define RCU_FANOUT_SQ        (RCU_FANOUT * RCU_FANOUT)
-#define RCU_FANOUT_CUBE              (RCU_FANOUT_SQ * RCU_FANOUT)
-#define RCU_FANOUT_FOURTH     (RCU_FANOUT_CUBE * RCU_FANOUT)
-
-#if NR_CPUS <= RCU_FANOUT
+#if CONFIG_RCU_FANOUT > 16
+#define RCU_FANOUT_LEAF       16
+#else /* #if CONFIG_RCU_FANOUT > 16 */
+#define RCU_FANOUT_LEAF       (CONFIG_RCU_FANOUT)
+#endif /* #else #if CONFIG_RCU_FANOUT > 16 */
+#define RCU_FANOUT_1         (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)
+
+#if NR_CPUS <= RCU_FANOUT_1
 #  define NUM_RCU_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
-#elif NR_CPUS <= RCU_FANOUT_SQ
+#elif NR_CPUS <= RCU_FANOUT_2
 #  define NUM_RCU_LVLS       2
 #  define NUM_RCU_LVL_0              1
-#  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
+#  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
-#elif NR_CPUS <= RCU_FANOUT_CUBE
+#elif NR_CPUS <= RCU_FANOUT_3
 #  define NUM_RCU_LVLS       3
 #  define NUM_RCU_LVL_0              1
-#  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ)
-#  define NUM_RCU_LVL_2              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
-#  define NUM_RCU_LVL_3              NR_CPUS
+#  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
-#elif NR_CPUS <= RCU_FANOUT_FOURTH
+#elif NR_CPUS <= RCU_FANOUT_4
 #  define NUM_RCU_LVLS       4
 #  define NUM_RCU_LVL_0              1
-#  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_CUBE)
-#  define NUM_RCU_LVL_2              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ)
-#  define NUM_RCU_LVL_3              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
-#  define NUM_RCU_LVL_4              NR_CPUS
+#  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)
 #else
 # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
-#endif /* #if (NR_CPUS) <= RCU_FANOUT */
+#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)
@@ -90,12 +95,12 @@ struct rcu_dynticks {
  * Definition for node within the RCU grace-period-detection hierarchy.
  */
 struct rcu_node {
-       spinlock_t lock;        /* Root rcu_node's lock protects some */
+       raw_spinlock_t lock;    /* Root rcu_node's lock protects some */
                                /*  rcu_state fields as well as following. */
-       long    gpnum;          /* Current grace period for this node. */
+       unsigned long gpnum;    /* Current grace period for this node. */
                                /*  This will either be equal to or one */
                                /*  behind the root rcu_node's gpnum. */
-       long    completed;      /* Last grace period completed for this node. */
+       unsigned long completed; /* Last GP completed for this node. */
                                /*  This will either be equal to or one */
                                /*  behind the root rcu_node's gpnum. */
        unsigned long qsmask;   /* CPUs or groups that need to switch in */
@@ -161,11 +166,11 @@ struct rcu_node {
 /* Per-CPU data for read-copy update. */
 struct rcu_data {
        /* 1) quiescent-state and grace-period handling : */
-       long            completed;      /* Track rsp->completed gp number */
+       unsigned long   completed;      /* Track rsp->completed gp number */
                                        /*  in order to detect GP end. */
-       long            gpnum;          /* Highest gp number that this CPU */
+       unsigned long   gpnum;          /* Highest gp number that this CPU */
                                        /*  is aware of having started. */
-       long            passed_quiesc_completed;
+       unsigned long   passed_quiesc_completed;
                                        /* Value of completed at time of qs. */
        bool            passed_quiesc;  /* User-mode/idle loop etc. */
        bool            qs_pending;     /* Core waits for quiesc state. */
@@ -202,6 +207,9 @@ struct rcu_data {
        long            qlen;           /* # of queued callbacks */
        long            qlen_last_fqs_check;
                                        /* qlen at last check for QS forcing */
+       unsigned long   n_cbs_invoked;  /* count of RCU cbs invoked. */
+       unsigned long   n_cbs_orphaned; /* RCU cbs orphaned by dying CPU */
+       unsigned long   n_cbs_adopted;  /* RCU cbs adopted from dying CPU */
        unsigned long   n_force_qs_snap;
                                        /* did other CPU force QS recently? */
        long            blimit;         /* Upper limit on a processed batch */
@@ -221,14 +229,15 @@ struct rcu_data {
        unsigned long resched_ipi;      /* Sent a resched IPI. */
 
        /* 5) __rcu_pending() statistics. */
-       long n_rcu_pending;             /* rcu_pending() calls since boot. */
-       long n_rp_qs_pending;
-       long n_rp_cb_ready;
-       long n_rp_cpu_needs_gp;
-       long n_rp_gp_completed;
-       long n_rp_gp_started;
-       long n_rp_need_fqs;
-       long n_rp_need_nothing;
+       unsigned long n_rcu_pending;    /* rcu_pending() calls since boot. */
+       unsigned long n_rp_qs_pending;
+       unsigned long n_rp_report_qs;
+       unsigned long n_rp_cb_ready;
+       unsigned long n_rp_cpu_needs_gp;
+       unsigned long n_rp_gp_completed;
+       unsigned long n_rp_gp_started;
+       unsigned long n_rp_need_fqs;
+       unsigned long n_rp_need_nothing;
 
        int cpu;
 };
@@ -237,22 +246,37 @@ struct rcu_data {
 #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_SAVE_COMPLETED     3       /* Need to save rsp->completed. */
-#define RCU_FORCE_QS           4       /* Need to force quiescent state. */
+#define RCU_FORCE_QS           3       /* Need to force quiescent state. */
 #ifdef CONFIG_NO_HZ
 #define RCU_SIGNAL_INIT                RCU_SAVE_DYNTICK
 #else /* #ifdef CONFIG_NO_HZ */
-#define RCU_SIGNAL_INIT                RCU_SAVE_COMPLETED
+#define RCU_SIGNAL_INIT                RCU_FORCE_QS
 #endif /* #else #ifdef CONFIG_NO_HZ */
 
 #define RCU_JIFFIES_TILL_FORCE_QS       3      /* for rsp->jiffies_force_qs */
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
-#define RCU_SECONDS_TILL_STALL_CHECK   (10 * HZ)  /* for rsp->jiffies_stall */
-#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ)  /* for rsp->jiffies_stall */
-#define RCU_STALL_RAT_DELAY            2         /* Allow other CPUs time */
-                                                 /*  to take at least one */
-                                                 /*  scheduling clock irq */
-                                                 /*  before ratting on them. */
+
+#ifdef CONFIG_PROVE_RCU
+#define RCU_STALL_DELAY_DELTA         (5 * HZ)
+#else
+#define RCU_STALL_DELAY_DELTA         0
+#endif
+
+#define RCU_SECONDS_TILL_STALL_CHECK   (CONFIG_RCU_CPU_STALL_TIMEOUT * HZ + \
+                                       RCU_STALL_DELAY_DELTA)
+                                               /* for rsp->jiffies_stall */
+#define RCU_SECONDS_TILL_STALL_RECHECK (3 * RCU_SECONDS_TILL_STALL_CHECK + 30)
+                                               /* for rsp->jiffies_stall */
+#define RCU_STALL_RAT_DELAY            2       /* Allow other CPUs time */
+                                               /*  to take at least one */
+                                               /*  scheduling clock irq */
+                                               /*  before ratting on them. */
+
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR_RUNNABLE
+#define RCU_CPU_STALL_SUPPRESS_INIT 0
+#else
+#define RCU_CPU_STALL_SUPPRESS_INIT 1
+#endif
 
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
@@ -271,7 +295,7 @@ struct rcu_state {
        struct rcu_node *level[NUM_RCU_LVLS];   /* Hierarchy levels. */
        u32 levelcnt[MAX_RCU_LVLS + 1];         /* # nodes in each level. */
        u8 levelspread[NUM_RCU_LVLS];           /* kids/node in each level. */
-       struct rcu_data *rda[NR_CPUS];          /* array of rdp pointers. */
+       struct rcu_data __percpu *rda;          /* pointer of percu rcu_data. */
 
        /* The following fields are guarded by the root rcu_node's lock. */
 
@@ -279,25 +303,20 @@ struct rcu_state {
                                                /* Force QS state. */
        u8      fqs_active;                     /* force_quiescent_state() */
                                                /*  is running. */
-       long    gpnum;                          /* Current gp number. */
-       long    completed;                      /* # of last completed gp. */
+       u8      fqs_need_gp;                    /* A CPU was prevented from */
+                                               /*  starting a new grace */
+                                               /*  period because */
+                                               /*  force_quiescent_state() */
+                                               /*  was running. */
+       unsigned long gpnum;                    /* Current gp number. */
+       unsigned long completed;                /* # of last completed gp. */
 
        /* End of fields guarded by root rcu_node's lock. */
 
-       spinlock_t onofflock;                   /* exclude on/offline and */
-                                               /*  starting new GP.  Also */
-                                               /*  protects the following */
-                                               /*  orphan_cbs fields. */
-       struct rcu_head *orphan_cbs_list;       /* list of rcu_head structs */
-                                               /*  orphaned by all CPUs in */
-                                               /*  a given leaf rcu_node */
-                                               /*  going offline. */
-       struct rcu_head **orphan_cbs_tail;      /* And tail pointer. */
-       long orphan_qlen;                       /* Number of orphaned cbs. */
-       spinlock_t fqslock;                     /* Only one task forcing */
+       raw_spinlock_t onofflock;               /* exclude on/offline and */
+                                               /*  starting new GP. */
+       raw_spinlock_t fqslock;                 /* Only one task forcing */
                                                /*  quiescent states. */
-       long    completed_fqs;                  /* Value of completed @ snap. */
-                                               /*  Protected by fqslock. */
        unsigned long jiffies_force_qs;         /* Time at which to invoke */
                                                /*  force_quiescent_state(). */
        unsigned long n_force_qs;               /* Number of calls to */
@@ -312,6 +331,7 @@ struct rcu_state {
        unsigned long jiffies_stall;            /* Time at which to check */
                                                /*  for CPU stalls. */
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+       char *name;                             /* Name of structure. */
 };
 
 /* Return values for rcu_preempt_offline_tasks(). */
@@ -321,8 +341,6 @@ struct rcu_state {
 #define RCU_OFL_TASKS_EXP_GP   0x2             /* Tasks blocking expedited */
                                                /*  GP were moved to root. */
 
-#ifdef RCU_TREE_NONCORE
-
 /*
  * RCU implementation internal declarations:
  */
@@ -337,7 +355,7 @@ extern struct rcu_state rcu_preempt_state;
 DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
-#else /* #ifdef RCU_TREE_NONCORE */
+#ifndef RCU_TREE_NONCORE
 
 /* Forward declarations for rcutree_plugin.h */
 static void rcu_bootup_announce(void);
@@ -349,7 +367,9 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
                                      unsigned long flags);
 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+static void rcu_print_detail_task_stall(struct rcu_state *rsp);
 static void rcu_print_task_stall(struct rcu_node *rnp);
+static void rcu_preempt_stall_reset(void);
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
 #ifdef CONFIG_HOTPLUG_CPU
@@ -367,7 +387,8 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp);
 static int rcu_preempt_pending(int cpu);
 static int rcu_preempt_needs_cpu(int cpu);
 static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
-static void rcu_preempt_send_cbs_to_orphanage(void);
+static void rcu_preempt_send_cbs_to_online(void);
 static void __init __rcu_init_preempt(void);
+static void rcu_needs_cpu_flush(void);
 
-#endif /* #else #ifdef RCU_TREE_NONCORE */
+#endif /* #ifndef RCU_TREE_NONCORE */