1 files changed, 22 insertions, 12 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4cae9b81a1f8..2127e959e0f4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -293,6 +293,9 @@ extern void sched_show_task(struct task_struct *p);
 extern void softlockup_tick(void);
 extern void touch_softlockup_watchdog(void);
 extern void touch_all_softlockup_watchdogs(void);
+extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
+                                    struct file *filp, void __user *buffer,
+                                    size_t *lenp, loff_t *ppos);
 extern unsigned int  softlockup_panic;
 extern unsigned long sysctl_hung_task_check_count;
 extern unsigned long sysctl_hung_task_timeout_secs;
@@ -440,6 +443,7 @@ struct pacct_struct {
  * @utime:              time spent in user mode, in &cputime_t units
  * @stime:              time spent in kernel mode, in &cputime_t units
  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
+ * @lock:               lock for fields in this struct
  *
  * This structure groups together three kinds of CPU time that are
  * tracked for threads and thread groups.  Most things considering
@@ -450,6 +454,7 @@ struct task_cputime {
         cputime_t utime;
         cputime_t stime;
         unsigned long long sum_exec_runtime;
+        spinlock_t lock;
 };
 /* Alternate field names when used to cache expirations. */
 #define prof_exp        stime
@@ -465,7 +470,7 @@ struct task_cputime {
  * used for thread group CPU clock calculations.
  */
 struct thread_group_cputime {
-        struct task_cputime *totals;
+        struct task_cputime totals;
 };
 
 /*
@@ -626,7 +631,6 @@ struct user_struct {
         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 #endif
 #ifdef CONFIG_EPOLL
-        atomic_t epoll_devs;    /* The number of epoll descriptors currently open */
         atomic_t epoll_watches; /* The number of file descriptors currently watched */
 #endif
 #ifdef CONFIG_POSIX_MQUEUE
@@ -2180,24 +2184,30 @@ static inline int spin_needbreak(spinlock_t *lock)
  * Thread group CPU time accounting.
  */
 
-extern int thread_group_cputime_alloc(struct task_struct *);
-extern void thread_group_cputime(struct task_struct *, struct task_cputime *);
-
-static inline void thread_group_cputime_init(struct signal_struct *sig)
+static inline
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
 {
-        sig->cputime.totals = NULL;
+        struct task_cputime *totals = &tsk->signal->cputime.totals;
+        unsigned long flags;
+
+        spin_lock_irqsave(&totals->lock, flags);
+        *times = *totals;
+        spin_unlock_irqrestore(&totals->lock, flags);
 }
 
-static inline int thread_group_cputime_clone_thread(struct task_struct *curr)
+static inline void thread_group_cputime_init(struct signal_struct *sig)
 {
-        if (curr->signal->cputime.totals)
-                return 0;
-        return thread_group_cputime_alloc(curr);
+        sig->cputime.totals = (struct task_cputime){
+                .utime = cputime_zero,
+                .stime = cputime_zero,
+                .sum_exec_runtime = 0,
+        };
+
+        spin_lock_init(&sig->cputime.totals.lock);
 }
 
 static inline void thread_group_cputime_free(struct signal_struct *sig)
 {
-        free_percpu(sig->cputime.totals);
 }
 
 /*