locking, sched: Annotate thread_group_cputimer as raw

The thread_group_cputimer lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index d14e058..08ffab0 100644 (file)
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -42,7 +42,7 @@ extern struct fs_struct init_fs;
        .cputimer       = {                                             \
                .cputime = INIT_CPUTIME,                                \
                .running = 0,                                           \
-               .lock = __SPIN_LOCK_UNLOCKED(sig.cputimer.lock),        \
+               .lock = __RAW_SPIN_LOCK_UNLOCKED(sig.cputimer.lock),    \
        },                                                              \
        .cred_guard_mutex =                                             \
                 __MUTEX_INITIALIZER(sig.cred_guard_mutex),             \

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4ac2c05..e672236 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -510,7 +510,7 @@ struct task_cputime {
 struct thread_group_cputimer {
        struct task_cputime cputime;
        int running;
-       spinlock_t lock;
+       raw_spinlock_t lock;
 };
 
 #include <linux/rwsem.h>
@@ -2566,7 +2566,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
 
 static inline void thread_group_cputime_init(struct signal_struct *sig)
 {
-       spin_lock_init(&sig->cputimer.lock);
+       raw_spin_lock_init(&sig->cputimer.lock);
 }
 
 /*

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 58f405b..41440cc 100644 (file)
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -274,7 +274,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
        struct task_cputime sum;
        unsigned long flags;
 
-       spin_lock_irqsave(&cputimer->lock, flags);
+       raw_spin_lock_irqsave(&cputimer->lock, flags);
        if (!cputimer->running) {
                cputimer->running = 1;
                /*
@@ -287,7 +287,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
                update_gt_cputime(&cputimer->cputime, &sum);
        }
        *times = cputimer->cputime;
-       spin_unlock_irqrestore(&cputimer->lock, flags);
+       raw_spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
 /*
@@ -997,9 +997,9 @@ static void stop_process_timers(struct signal_struct *sig)
        struct thread_group_cputimer *cputimer = &sig->cputimer;
        unsigned long flags;
 
-       spin_lock_irqsave(&cputimer->lock, flags);
+       raw_spin_lock_irqsave(&cputimer->lock, flags);
        cputimer->running = 0;
-       spin_unlock_irqrestore(&cputimer->lock, flags);
+       raw_spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
 static u32 onecputick;
@@ -1289,9 +1289,9 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
        if (sig->cputimer.running) {
                struct task_cputime group_sample;
 
-               spin_lock(&sig->cputimer.lock);
+               raw_spin_lock(&sig->cputimer.lock);
                group_sample = sig->cputimer.cputime;
-               spin_unlock(&sig->cputimer.lock);
+               raw_spin_unlock(&sig->cputimer.lock);
 
                if (task_cputime_expired(&group_sample, &sig->cputime_expires))
                        return 1;

diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 331e01b..87f9e36 100644 (file)
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -282,10 +282,10 @@ static inline void account_group_user_time(struct task_struct *tsk,
        if (!cputimer->running)
                return;
 
-       spin_lock(&cputimer->lock);
+       raw_spin_lock(&cputimer->lock);
        cputimer->cputime.utime =
                cputime_add(cputimer->cputime.utime, cputime);
-       spin_unlock(&cputimer->lock);
+       raw_spin_unlock(&cputimer->lock);
 }
 
 /**
@@ -306,10 +306,10 @@ static inline void account_group_system_time(struct task_struct *tsk,
        if (!cputimer->running)
                return;
 
-       spin_lock(&cputimer->lock);
+       raw_spin_lock(&cputimer->lock);
        cputimer->cputime.stime =
                cputime_add(cputimer->cputime.stime, cputime);
-       spin_unlock(&cputimer->lock);
+       raw_spin_unlock(&cputimer->lock);
 }
 
 /**
@@ -330,7 +330,7 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
        if (!cputimer->running)
                return;
 
-       spin_lock(&cputimer->lock);
+       raw_spin_lock(&cputimer->lock);
        cputimer->cputime.sum_exec_runtime += ns;
-       spin_unlock(&cputimer->lock);
+       raw_spin_unlock(&cputimer->lock);
 }