rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments

[safe/jmp/linux-2.6] / include / linux / sched.h

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1bc6fae..855fd0d 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -92,7 +92,6 @@ struct sched_param {
 
 #include <asm/processor.h>
 
-struct mem_cgroup;
 struct exec_domain;
 struct futex_pi_state;
 struct robust_list_head;
@@ -210,7 +209,7 @@ extern unsigned long long time_sync_thresh;
                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 #define task_contributes_to_load(task) \
                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
-                                (task->flags & PF_FROZEN) == 0)
+                                (task->flags & PF_FREEZING) == 0)
 
 #define __set_task_state(tsk, state_value)             \
        do { (tsk)->state = (state_value); } while (0)
@@ -350,8 +349,20 @@ extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
 struct nsproxy;
 struct user_namespace;
 
-/* Maximum number of active map areas.. This is a random (large) number */
-#define DEFAULT_MAX_MAP_COUNT  65536
+/*
+ * Default maximum number of active map areas, this limits the number of vmas
+ * per mm struct. Users can overwrite this number by sysctl but there is a
+ * problem.
+ *
+ * When a program's coredump is generated as ELF format, a section is created
+ * per a vma. In ELF, the number of sections is represented in unsigned short.
+ * This means the number of sections should be smaller than 65535 at coredump.
+ * Because the kernel adds some informative sections to a image of program at
+ * generating coredump, we need some margin. The number of extra sections is
+ * 1-3 now and depends on arch. We use "5" as safe margin, here.
+ */
+#define MAPCOUNT_ELF_CORE_MARGIN       (5)
+#define DEFAULT_MAX_MAP_COUNT  (USHORT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
 
 extern int sysctl_max_map_count;
 
@@ -487,6 +498,15 @@ struct task_cputime {
                .sum_exec_runtime = 0,                          \
        }
 
+/*
+ * Disable preemption until the scheduler is running.
+ * Reset by start_kernel()->sched_init()->init_idle().
+ *
+ * We include PREEMPT_ACTIVE to avoid cond_resched() from working
+ * before the scheduler is active -- see should_resched().
+ */
+#define INIT_PREEMPT_COUNT     (1 + PREEMPT_ACTIVE)
+
 /**
  * struct thread_group_cputimer - thread group interval timer counts
  * @cputime:           thread group interval timers.
@@ -674,7 +694,7 @@ struct user_struct {
        struct task_group *tg;
 #ifdef CONFIG_SYSFS
        struct kobject kobj;
-       struct work_struct work;
+       struct delayed_work work;
 #endif
 #endif
 
@@ -1143,6 +1163,8 @@ struct sched_rt_entity {
 #endif
 };
 
+struct rcu_node;
+
 struct task_struct {
        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
        void *stack;
@@ -1185,10 +1207,12 @@ struct task_struct {
        unsigned int policy;
        cpumask_t cpus_allowed;
 
-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU
        int rcu_read_lock_nesting;
-       int rcu_flipctr_idx;
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
+       char rcu_read_unlock_special;
+       struct rcu_node *rcu_blocked_node;
+       struct list_head rcu_node_entry;
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
        struct sched_info sched_info;
@@ -1660,6 +1684,7 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define PF_MEMALLOC    0x00000800      /* Allocating memory */
 #define PF_FLUSHER     0x00001000      /* responsible for disk writeback */
 #define PF_USED_MATH   0x00002000      /* if unset the fpu must be initialized before use */
+#define PF_FREEZING    0x00004000      /* freeze in progress. do not account to load */
 #define PF_NOFREEZE    0x00008000      /* this thread should not be frozen */
 #define PF_FROZEN      0x00010000      /* frozen for system suspend */
 #define PF_FSTRANS     0x00020000      /* inside a filesystem transaction */
@@ -1702,6 +1727,28 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
 #define used_math() tsk_used_math(current)
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
+#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
+#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
+#define RCU_READ_UNLOCK_GOT_QS  (1 << 2) /* CPU has responded to RCU core. */
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+       p->rcu_read_lock_nesting = 0;
+       p->rcu_read_unlock_special = 0;
+       p->rcu_blocked_node = NULL;
+       INIT_LIST_HEAD(&p->rcu_node_entry);
+}
+
+#else
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+}
+
+#endif
+
 #ifdef CONFIG_SMP
 extern int set_cpus_allowed_ptr(struct task_struct *p,
                                const struct cpumask *new_mask);
@@ -1879,9 +1926,6 @@ extern struct pid_namespace init_pid_ns;
 /*
  * find a task by one of its numerical ids
  *
- * find_task_by_pid_type_ns():
- *      it is the most generic call - it finds a task by all id,
- *      type and namespace specified
  * find_task_by_pid_ns():
  *      finds a task by its pid in the specified namespace
  * find_task_by_vpid():
@@ -1890,9 +1934,6 @@ extern struct pid_namespace init_pid_ns;
  * see also find_vpid() etc in include/linux/pid.h
  */
 
-extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
-               struct pid_namespace *ns);
-
 extern struct task_struct *find_task_by_vpid(pid_t nr);
 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
                struct pid_namespace *ns);