itimers: Merge ITIMER_VIRT and ITIMER_PROF

Both cpu itimers have same data flow in the few places, this
patch make unification of code related with VIRT and PROF
itimers.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 46 insertions, 52 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index bece7c0b67b2..9b2d5e4dc8c4 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -14,11 +14,11 @@
  */
 void update_rlimit_cpu(unsigned long rlim_new)
 {
-        cputime_t cputime;
+        cputime_t cputime = secs_to_cputime(rlim_new);
+        struct signal_struct *const sig = current->signal;
 
-        cputime = secs_to_cputime(rlim_new);
-        if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
-            cputime_gt(current->signal->it_prof_expires, cputime)) {
+        if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
+            cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
                 spin_lock_irq(&current->sighand->siglock);
                 set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
                 spin_unlock_irq(&current->sighand->siglock);
@@ -613,6 +613,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                                 break;
                         }
                 } else {
+                        struct signal_struct *const sig = p->signal;
+                        union cpu_time_count *exp = &timer->it.cpu.expires;
+
                         /*
                          * For a process timer, set the cached expiration time.
                          */
@@ -620,30 +623,27 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                         default:
                                 BUG();
                         case CPUCLOCK_VIRT:
-                                if (!cputime_eq(p->signal->it_virt_expires,
+                                if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires,
                                                 cputime_zero) &&
-                                    cputime_lt(p->signal->it_virt_expires,
-                                               timer->it.cpu.expires.cpu))
+                                    cputime_lt(sig->it[CPUCLOCK_VIRT].expires,
+                                               exp->cpu))
                                         break;
-                                p->signal->cputime_expires.virt_exp =
-                                        timer->it.cpu.expires.cpu;
+                                sig->cputime_expires.virt_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_PROF:
-                                if (!cputime_eq(p->signal->it_prof_expires,
+                                if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires,
                                                 cputime_zero) &&
-                                    cputime_lt(p->signal->it_prof_expires,
-                                               timer->it.cpu.expires.cpu))
+                                    cputime_lt(sig->it[CPUCLOCK_PROF].expires,
+                                               exp->cpu))
                                         break;
-                                i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+                                i = sig->rlim[RLIMIT_CPU].rlim_cur;
                                 if (i != RLIM_INFINITY &&
-                                    i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+                                    i <= cputime_to_secs(exp->cpu))
                                         break;
-                                p->signal->cputime_expires.prof_exp =
-                                        timer->it.cpu.expires.cpu;
+                                sig->cputime_expires.prof_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_SCHED:
-                                p->signal->cputime_expires.sched_exp =
-                                        timer->it.cpu.expires.sched;
+                                sig->cputime_expires.sched_exp = exp->sched;
                                 break;
                         }
                 }
@@ -1070,6 +1070,27 @@ static void stop_process_timers(struct task_struct *tsk)
         spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+                             cputime_t *expires, cputime_t cur_time, int signo)
+{
+        if (cputime_eq(it->expires, cputime_zero))
+                return;
+
+        if (cputime_ge(cur_time, it->expires)) {
+                it->expires = it->incr;
+                if (!cputime_eq(it->expires, cputime_zero))
+                        it->expires = cputime_add(it->expires, cur_time);
+
+                __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+        }
+
+        if (!cputime_eq(it->expires, cputime_zero) &&
+            (cputime_eq(*expires, cputime_zero) ||
+             cputime_lt(it->expires, *expires))) {
+                *expires = it->expires;
+        }
+}
+
 /*
  * Check for any per-thread CPU timers that have fired and move them
  * off the tsk->*_timers list onto the firing list.  Per-thread timers
@@ -1089,10 +1110,10 @@ static void check_process_timers(struct task_struct *tsk,
          * Don't sample the current process CPU clocks if there are no timers.
          */
         if (list_empty(&timers[CPUCLOCK_PROF]) &&
-            cputime_eq(sig->it_prof_expires, cputime_zero) &&
+            cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
             sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
             list_empty(&timers[CPUCLOCK_VIRT]) &&
-            cputime_eq(sig->it_virt_expires, cputime_zero) &&
+            cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
             list_empty(&timers[CPUCLOCK_SCHED])) {
                 stop_process_timers(tsk);
                 return;
@@ -1152,38 +1173,11 @@ static void check_process_timers(struct task_struct *tsk,
         /*
          * Check for the special case process timers.
          */
-        if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-                if (cputime_ge(ptime, sig->it_prof_expires)) {
-                        /* ITIMER_PROF fires and reloads.  */
-                        sig->it_prof_expires = sig->it_prof_incr;
-                        if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-                                sig->it_prof_expires = cputime_add(
-                                        sig->it_prof_expires, ptime);
-                        }
-                        __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
-                }
-                if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
-                    (cputime_eq(prof_expires, cputime_zero) ||
-                     cputime_lt(sig->it_prof_expires, prof_expires))) {
-                        prof_expires = sig->it_prof_expires;
-                }
-        }
-        if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-                if (cputime_ge(utime, sig->it_virt_expires)) {
-                        /* ITIMER_VIRTUAL fires and reloads.  */
-                        sig->it_virt_expires = sig->it_virt_incr;
-                        if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-                                sig->it_virt_expires = cputime_add(
-                                        sig->it_virt_expires, utime);
-                        }
-                        __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
-                }
-                if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
-                    (cputime_eq(virt_expires, cputime_zero) ||
-                     cputime_lt(sig->it_virt_expires, virt_expires))) {
-                        virt_expires = sig->it_virt_expires;
-                }
-        }
+        check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+                         SIGPROF);
+        check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+                         SIGVTALRM);
+
         if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
                 unsigned long psecs = cputime_to_secs(ptime);
                 cputime_t x;