9p: remove unnecessary dentry_unhash on rmdir, dir rename
[pandora-kernel.git] / kernel / rcutree.h
index e1a6663..2576648 100644 (file)
@@ -91,6 +91,14 @@ struct rcu_dynticks {
                                /*  remains even for nmi from irq handler. */
 };
 
+/* RCU's kthread states for tracing. */
+#define RCU_KTHREAD_STOPPED  0
+#define RCU_KTHREAD_RUNNING  1
+#define RCU_KTHREAD_WAITING  2
+#define RCU_KTHREAD_OFFCPU   3
+#define RCU_KTHREAD_YIELDING 4
+#define RCU_KTHREAD_MAX      4
+
 /*
  * Definition for node within the RCU grace-period-detection hierarchy.
  */
@@ -109,10 +117,11 @@ struct rcu_node {
                                /*  an rcu_data structure, otherwise, each */
                                /*  bit corresponds to a child rcu_node */
                                /*  structure. */
-       unsigned long expmask;  /* Groups that have ->blocked_tasks[] */
+       unsigned long expmask;  /* Groups that have ->blkd_tasks */
                                /*  elements that need to drain to allow the */
                                /*  current expedited grace period to */
                                /*  complete (only for TREE_PREEMPT_RCU). */
+       unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */
        unsigned long qsmaskinit;
                                /* Per-GP initial value for qsmask & expmask. */
        unsigned long grpmask;  /* Mask to apply to parent qsmask. */
@@ -122,11 +131,68 @@ struct rcu_node {
        u8      grpnum;         /* CPU/group number for next level up. */
        u8      level;          /* root is at level 0. */
        struct rcu_node *parent;
-       struct list_head blocked_tasks[4];
-                               /* Tasks blocked in RCU read-side critsect. */
-                               /*  Grace period number (->gpnum) x blocked */
-                               /*  by tasks on the (x & 0x1) element of the */
-                               /*  blocked_tasks[] array. */
+       struct list_head blkd_tasks;
+                               /* Tasks blocked in RCU read-side critical */
+                               /*  section.  Tasks are placed at the head */
+                               /*  of this list and age towards the tail. */
+       struct list_head *gp_tasks;
+                               /* Pointer to the first task blocking the */
+                               /*  current grace period, or NULL if there */
+                               /*  is no such task. */
+       struct list_head *exp_tasks;
+                               /* Pointer to the first task blocking the */
+                               /*  current expedited grace period, or NULL */
+                               /*  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 */
+                               /*  boosting is needed for this rcu_node */
+                               /*  structure.  If there are no tasks */
+                               /*  queued on this rcu_node structure that */
+                               /*  are blocking the current grace period, */
+                               /*  there can be no such task. */
+       unsigned long boost_time;
+                               /* When to start boosting (jiffies). */
+       struct task_struct *boost_kthread_task;
+                               /* kthread that takes care of priority */
+                               /*  boosting for this rcu_node structure. */
+       wait_queue_head_t boost_wq;
+                               /* Wait queue on which to park the boost */
+                               /*  kthread. */
+       unsigned int boost_kthread_status;
+                               /* State of boost_kthread_task for tracing. */
+       unsigned long n_tasks_boosted;
+                               /* Total number of tasks boosted. */
+       unsigned long n_exp_boosts;
+                               /* Number of tasks boosted for expedited GP. */
+       unsigned long n_normal_boosts;
+                               /* Number of tasks boosted for normal GP. */
+       unsigned long n_balk_blkd_tasks;
+                               /* Refused to boost: no blocked tasks. */
+       unsigned long n_balk_exp_gp_tasks;
+                               /* Refused to boost: nothing blocking GP. */
+       unsigned long n_balk_boost_tasks;
+                               /* Refused to boost: already boosting. */
+       unsigned long n_balk_notblocked;
+                               /* Refused to boost: RCU RS CS still running. */
+       unsigned long n_balk_notyet;
+                               /* Refused to boost: not yet time. */
+       unsigned long n_balk_nos;
+                               /* Refused to boost: not sure why, though. */
+                               /*  This can happen due to race conditions. */
+#endif /* #ifdef CONFIG_RCU_BOOST */
+       struct task_struct *node_kthread_task;
+                               /* kthread that takes care of this rcu_node */
+                               /*  structure, for example, awakening the */
+                               /*  per-CPU kthreads as needed. */
+       wait_queue_head_t node_wq;
+                               /* Wait queue on which to park the per-node */
+                               /*  kthread. */
+       unsigned int node_kthread_status;
+                               /* State of node_kthread_task for tracing. */
 } ____cacheline_internodealigned_in_smp;
 
 /*
@@ -175,7 +241,7 @@ struct rcu_data {
        bool            passed_quiesc;  /* User-mode/idle loop etc. */
        bool            qs_pending;     /* Core waits for quiesc state. */
        bool            beenonline;     /* CPU online at least once. */
-       bool            preemptable;    /* Preemptable RCU? */
+       bool            preemptible;    /* Preemptible RCU? */
        struct rcu_node *mynode;        /* This CPU's leaf of hierarchy */
        unsigned long grpmask;          /* Mask to apply to leaf qsmask. */
 
@@ -321,6 +387,8 @@ struct rcu_state {
                                                /*  but in jiffies. */
        unsigned long jiffies_stall;            /* Time at which to check */
                                                /*  for CPU stalls. */
+       unsigned long gp_max;                   /* Maximum GP duration in */
+                                               /*  jiffies. */
        char *name;                             /* Name of structure. */
 };
 
@@ -351,7 +419,7 @@ DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
 static void rcu_bootup_announce(void);
 long rcu_batches_completed(void);
 static void rcu_preempt_note_context_switch(int cpu);
-static int rcu_preempted_readers(struct rcu_node *rnp);
+static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp);
 #ifdef CONFIG_HOTPLUG_CPU
 static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
                                      unsigned long flags);
@@ -378,5 +446,13 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
 static void rcu_preempt_send_cbs_to_online(void);
 static void __init __rcu_init_preempt(void);
 static void rcu_needs_cpu_flush(void);
+static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp);
+static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
+static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp,
+                                         cpumask_var_t cm);
+static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
+static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
+                                                struct rcu_node *rnp,
+                                                int rnp_index);
 
 #endif /* #ifndef RCU_TREE_NONCORE */