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authorStanislaw Gruszka <sgruszka@redhat.com>2009-07-29 10:15:28 (GMT)
committerIngo Molnar <mingo@elte.hu>2009-08-03 12:48:36 (GMT)
commitd1e3b6d195770bd422e3229b88edfc154b6a27dd (patch)
tree153a0bb49967c4d489a510c9e673d07f4e560a6c
parent8356b5f9c424e5831715abbce747197c30d1fd71 (diff)
downloadlinux-d1e3b6d195770bd422e3229b88edfc154b6a27dd.tar.xz
itimers: Simplify arm_timer() code a bit
Don't update values in expiration cache when new ones are equal. Add expire_le() and expire_gt() helpers to simplify the code. 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: <1248862529-6063-4-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/posix-cpu-timers.c44
1 files changed, 23 insertions, 21 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index b60d644..69c9237435 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -541,6 +541,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
now);
}
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+ return cputime_eq(expires, cputime_zero) ||
+ cputime_gt(expires, new_exp);
+}
+
+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+ return !cputime_eq(expires, cputime_zero) &&
+ cputime_le(expires, new_exp);
+}
/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
@@ -585,31 +596,26 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ union cpu_time_count *exp = &nt->expires;
+
switch (CPUCLOCK_WHICH(timer->it_clock)) {
default:
BUG();
case CPUCLOCK_PROF:
- if (cputime_eq(p->cputime_expires.prof_exp,
- cputime_zero) ||
- cputime_gt(p->cputime_expires.prof_exp,
- nt->expires.cpu))
- p->cputime_expires.prof_exp =
- nt->expires.cpu;
+ if (expires_gt(p->cputime_expires.prof_exp,
+ exp->cpu))
+ p->cputime_expires.prof_exp = exp->cpu;
break;
case CPUCLOCK_VIRT:
- if (cputime_eq(p->cputime_expires.virt_exp,
- cputime_zero) ||
- cputime_gt(p->cputime_expires.virt_exp,
- nt->expires.cpu))
- p->cputime_expires.virt_exp =
- nt->expires.cpu;
+ if (expires_gt(p->cputime_expires.virt_exp,
+ exp->cpu))
+ p->cputime_expires.virt_exp = exp->cpu;
break;
case CPUCLOCK_SCHED:
if (p->cputime_expires.sched_exp == 0 ||
- p->cputime_expires.sched_exp >
- nt->expires.sched)
+ p->cputime_expires.sched_exp > exp->sched)
p->cputime_expires.sched_exp =
- nt->expires.sched;
+ exp->sched;
break;
}
} else {
@@ -623,17 +629,13 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
default:
BUG();
case CPUCLOCK_VIRT:
- if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires,
- cputime_zero) &&
- cputime_lt(sig->it[CPUCLOCK_VIRT].expires,
+ if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
exp->cpu))
break;
sig->cputime_expires.virt_exp = exp->cpu;
break;
case CPUCLOCK_PROF:
- if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires,
- cputime_zero) &&
- cputime_lt(sig->it[CPUCLOCK_PROF].expires,
+ if (expires_le(sig->it[CPUCLOCK_PROF].expires,
exp->cpu))
break;
i = sig->rlim[RLIMIT_CPU].rlim_cur;