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Subject[PATCH resend4 3/3] itimers: simplify arm_timer() code a bit
Don't update values in expiration cache when new ones are equal. Add
expire_le() helper to simplify code. Make similar control flow on all
arm_timer() function.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
kernel/posix-cpu-timers.c | 46 ++++++++++++++++++++++----------------------
1 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index b60d644..ce16e22 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -541,6 +541,13 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
now);
}

+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+ if (!cputime_eq(expires, cputime_zero) && cputime_le(expires, new_exp))
+ return 1;
+ return 0;
+}
+
/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
@@ -585,31 +592,28 @@ 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_le(p->cputime_expires.prof_exp,
+ exp->cpu))
+ break;
+ 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_le(p->cputime_expires.virt_exp,
+ exp->cpu))
+ break;
+ 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 =
- nt->expires.sched;
+ if (p->cputime_expires.sched_exp == 0 &&
+ p->cputime_expires.sched_exp <= exp->sched)
+ break;
+ p->cputime_expires.sched_exp = exp->sched;
break;
}
} else {
@@ -623,17 +627,13 @@ 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;
--
1.5.5.6


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