sched_rt: don't start timer when rt bandwidth disabled

[safe/jmp/linux-2.6] / kernel / itimer.c

diff --git a/kernel/itimer.c b/kernel/itimer.c
index a2dc375..58762f7 100644 (file)
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -7,7 +7,6 @@
 /* These are all the functions necessary to implement itimers */
 
 #include <linux/mm.h>
-#include <linux/smp_lock.h>
 #include <linux/interrupt.h>
 #include <linux/syscalls.h>
 #include <linux/time.h>
@@ -56,17 +55,15 @@ int do_getitimer(int which, struct itimerval *value)
                spin_unlock_irq(&tsk->sighand->siglock);
                break;
        case ITIMER_VIRTUAL:
-               read_lock(&tasklist_lock);
                spin_lock_irq(&tsk->sighand->siglock);
                cval = tsk->signal->it_virt_expires;
                cinterval = tsk->signal->it_virt_incr;
                if (!cputime_eq(cval, cputime_zero)) {
-                       struct task_struct *t = tsk;
-                       cputime_t utime = tsk->signal->utime;
-                       do {
-                               utime = cputime_add(utime, t->utime);
-                               t = next_thread(t);
-                       } while (t != tsk);
+                       struct task_cputime cputime;
+                       cputime_t utime;
+
+                       thread_group_cputimer(tsk, &cputime);
+                       utime = cputime.utime;
                        if (cputime_le(cval, utime)) { /* about to fire */
                                cval = jiffies_to_cputime(1);
                        } else {
@@ -74,25 +71,19 @@ int do_getitimer(int which, struct itimerval *value)
                        }
                }
                spin_unlock_irq(&tsk->sighand->siglock);
-               read_unlock(&tasklist_lock);
                cputime_to_timeval(cval, &value->it_value);
                cputime_to_timeval(cinterval, &value->it_interval);
                break;
        case ITIMER_PROF:
-               read_lock(&tasklist_lock);
                spin_lock_irq(&tsk->sighand->siglock);
                cval = tsk->signal->it_prof_expires;
                cinterval = tsk->signal->it_prof_incr;
                if (!cputime_eq(cval, cputime_zero)) {
-                       struct task_struct *t = tsk;
-                       cputime_t ptime = cputime_add(tsk->signal->utime,
-                                                     tsk->signal->stime);
-                       do {
-                               ptime = cputime_add(ptime,
-                                                   cputime_add(t->utime,
-                                                               t->stime));
-                               t = next_thread(t);
-                       } while (t != tsk);
+                       struct task_cputime times;
+                       cputime_t ptime;
+
+                       thread_group_cputimer(tsk, &times);
+                       ptime = cputime_add(times.utime, times.stime);
                        if (cputime_le(cval, ptime)) { /* about to fire */
                                cval = jiffies_to_cputime(1);
                        } else {
@@ -100,7 +91,6 @@ int do_getitimer(int which, struct itimerval *value)
                        }
                }
                spin_unlock_irq(&tsk->sighand->siglock);
-               read_unlock(&tasklist_lock);
                cputime_to_timeval(cval, &value->it_value);
                cputime_to_timeval(cinterval, &value->it_interval);
                break;
@@ -110,7 +100,7 @@ int do_getitimer(int which, struct itimerval *value)
        return 0;
 }
 
-asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
+SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
 {
        int error = -EFAULT;
        struct itimerval get_buffer;
@@ -128,21 +118,22 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 /*
  * The timer is automagically restarted, when interval != 0
  */
-int it_real_fn(void *data)
+enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 {
-       struct task_struct *tsk = (struct task_struct *) data;
-
-       send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
+       struct signal_struct *sig =
+               container_of(timer, struct signal_struct, real_timer);
 
-       if (tsk->signal->it_real_incr.tv64 != 0) {
-               hrtimer_forward(&tsk->signal->real_timer,
-                              tsk->signal->it_real_incr);
+       kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
 
-               return HRTIMER_RESTART;
-       }
        return HRTIMER_NORESTART;
 }
 
+/*
+ * Returns true if the timeval is in canonical form
+ */
+#define timeval_valid(t) \
+       (((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
+
 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 {
        struct task_struct *tsk = current;
@@ -150,6 +141,13 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
        ktime_t expires;
        cputime_t cval, cinterval, nval, ninterval;
 
+       /*
+        * Validate the timevals in value.
+        */
+       if (!timeval_valid(&value->it_value) ||
+           !timeval_valid(&value->it_interval))
+               return -EINVAL;
+
        switch (which) {
        case ITIMER_REAL:
 again:
@@ -165,17 +163,19 @@ again:
                        spin_unlock_irq(&tsk->sighand->siglock);
                        goto again;
                }
-               tsk->signal->it_real_incr =
-                       timeval_to_ktime(value->it_interval);
                expires = timeval_to_ktime(value->it_value);
-               if (expires.tv64 != 0)
-                       hrtimer_start(timer, expires, HRTIMER_REL);
+               if (expires.tv64 != 0) {
+                       tsk->signal->it_real_incr =
+                               timeval_to_ktime(value->it_interval);
+                       hrtimer_start(timer, expires, HRTIMER_MODE_REL);
+               } else
+                       tsk->signal->it_real_incr.tv64 = 0;
+
                spin_unlock_irq(&tsk->sighand->siglock);
                break;
        case ITIMER_VIRTUAL:
                nval = timeval_to_cputime(&value->it_value);
                ninterval = timeval_to_cputime(&value->it_interval);
-               read_lock(&tasklist_lock);
                spin_lock_irq(&tsk->sighand->siglock);
                cval = tsk->signal->it_virt_expires;
                cinterval = tsk->signal->it_virt_incr;
@@ -190,7 +190,6 @@ again:
                tsk->signal->it_virt_expires = nval;
                tsk->signal->it_virt_incr = ninterval;
                spin_unlock_irq(&tsk->sighand->siglock);
-               read_unlock(&tasklist_lock);
                if (ovalue) {
                        cputime_to_timeval(cval, &ovalue->it_value);
                        cputime_to_timeval(cinterval, &ovalue->it_interval);
@@ -199,7 +198,6 @@ again:
        case ITIMER_PROF:
                nval = timeval_to_cputime(&value->it_value);
                ninterval = timeval_to_cputime(&value->it_interval);
-               read_lock(&tasklist_lock);
                spin_lock_irq(&tsk->sighand->siglock);
                cval = tsk->signal->it_prof_expires;
                cinterval = tsk->signal->it_prof_incr;
@@ -214,7 +212,6 @@ again:
                tsk->signal->it_prof_expires = nval;
                tsk->signal->it_prof_incr = ninterval;
                spin_unlock_irq(&tsk->sighand->siglock);
-               read_unlock(&tasklist_lock);
                if (ovalue) {
                        cputime_to_timeval(cval, &ovalue->it_value);
                        cputime_to_timeval(cinterval, &ovalue->it_interval);
@@ -263,9 +260,8 @@ unsigned int alarm_setitimer(unsigned int seconds)
        return it_old.it_value.tv_sec;
 }
 
-asmlinkage long sys_setitimer(int which,
-                             struct itimerval __user *value,
-                             struct itimerval __user *ovalue)
+SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
+               struct itimerval __user *, ovalue)
 {
        struct itimerval set_buffer, get_buffer;
        int error;
@@ -281,6 +277,6 @@ asmlinkage long sys_setitimer(int which,
                return error;
 
        if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
-               return -EFAULT; 
+               return -EFAULT;
        return 0;
 }