[PATCH] simplify k_getrusage()

Factor out common code for different RUSAGE_xxx cases.

Don't take ->sighand->siglock in RUSAGE_SELF case, suggested by Ravikiran G
Thirumalai <kiran@scalex86.org>.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/sys.c b/kernel/sys.c
index 218937e837dcb08b3c7c473e46c1ae5153beb4dd..b6941e06d5d507a141a135294c8d29e62ddd59d3 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1692,7 +1692,10 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
        if (unlikely(!p->signal))
                return;
 
+       utime = stime = cputime_zero;
+
        switch (who) {
+               case RUSAGE_BOTH:
                case RUSAGE_CHILDREN:
                        spin_lock_irqsave(&p->sighand->siglock, flags);
                        utime = p->signal->cutime;
@@ -1702,22 +1705,11 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
                        r->ru_minflt = p->signal->cmin_flt;
                        r->ru_majflt = p->signal->cmaj_flt;
                        spin_unlock_irqrestore(&p->sighand->siglock, flags);
-                       cputime_to_timeval(utime, &r->ru_utime);
-                       cputime_to_timeval(stime, &r->ru_stime);
-                       break;
+
+                       if (who == RUSAGE_CHILDREN)
+                               break;
+
                case RUSAGE_SELF:
-                       spin_lock_irqsave(&p->sighand->siglock, flags);
-                       utime = stime = cputime_zero;
-                       goto sum_group;
-               case RUSAGE_BOTH:
-                       spin_lock_irqsave(&p->sighand->siglock, flags);
-                       utime = p->signal->cutime;
-                       stime = p->signal->cstime;
-                       r->ru_nvcsw = p->signal->cnvcsw;
-                       r->ru_nivcsw = p->signal->cnivcsw;
-                       r->ru_minflt = p->signal->cmin_flt;
-                       r->ru_majflt = p->signal->cmaj_flt;
-               sum_group:
                        utime = cputime_add(utime, p->signal->utime);
                        stime = cputime_add(stime, p->signal->stime);
                        r->ru_nvcsw += p->signal->nvcsw;
@@ -1734,13 +1726,14 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
                                r->ru_majflt += t->maj_flt;
                                t = next_thread(t);
                        } while (t != p);
-                       spin_unlock_irqrestore(&p->sighand->siglock, flags);
-                       cputime_to_timeval(utime, &r->ru_utime);
-                       cputime_to_timeval(stime, &r->ru_stime);
                        break;
+
                default:
                        BUG();
        }
+
+       cputime_to_timeval(utime, &r->ru_utime);
+       cputime_to_timeval(stime, &r->ru_stime);
 }
 
 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)