mm: per-thread vma caching

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / linux / sched.h

diff --git a/include/linux/sched.h b/include/linux/sched.h
index a781dec..d7ca410 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -59,6 +59,10 @@ struct sched_param {
 
 #define SCHED_ATTR_SIZE_VER0   48      /* sizeof first published struct */
 
+#define VMACACHE_BITS 2
+#define VMACACHE_SIZE (1U << VMACACHE_BITS)
+#define VMACACHE_MASK (VMACACHE_SIZE - 1)
+
 /*
  * Extended scheduling parameters data structure.
  *
@@ -1228,6 +1232,9 @@ struct task_struct {
 #ifdef CONFIG_COMPAT_BRK
        unsigned brk_randomized:1;
 #endif
+       /* per-thread vma caching */
+       u32 vmacache_seqnum;
+       struct vm_area_struct *vmacache[VMACACHE_SIZE];
 #if defined(SPLIT_RSS_COUNTING)
        struct task_rss_stat    rss_stat;
 #endif
@@ -1688,6 +1695,24 @@ static inline pid_t task_tgid_vnr(struct task_struct *tsk)
 }
 
 
+static int pid_alive(const struct task_struct *p);
+static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
+{
+       pid_t pid = 0;
+
+       rcu_read_lock();
+       if (pid_alive(tsk))
+               pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
+       rcu_read_unlock();
+
+       return pid;
+}
+
+static inline pid_t task_ppid_nr(const struct task_struct *tsk)
+{
+       return task_ppid_nr_ns(tsk, &init_pid_ns);
+}
+
 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
                                        struct pid_namespace *ns)
 {
@@ -1727,7 +1752,7 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk)
  *
  * Return: 1 if the process is alive. 0 otherwise.
  */
-static inline int pid_alive(struct task_struct *p)
+static inline int pid_alive(const struct task_struct *p)
 {
        return p->pids[PIDTYPE_PID].pid != NULL;
 }