linux-kernel - [tip:timers/posixtimers] itimers: Simplify arm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-d1e3b6d195770bd422e3229b88edfc154b6a27dd@git.kernel.org>
Date:	Mon, 3 Aug 2009 13:25:02 GMT
From:	tip-bot for Stanislaw Gruszka <sgruszka@...hat.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, paulus@...ba.org, hpa@...or.com,
	mingo@...hat.com, a.p.zijlstra@...llo.nl, benh@...nel.crashing.org,
	akpm@...ux-foundation.org, tglx@...utronix.de, oleg@...hat.com,
	sgruszka@...hat.com, mingo@...e.hu
Subject: [tip:timers/posixtimers] itimers: Simplify arm_timer() code a bit

Commit-ID:  d1e3b6d195770bd422e3229b88edfc154b6a27dd
Gitweb:     http://git.kernel.org/tip/d1e3b6d195770bd422e3229b88edfc154b6a27dd
Author:     Stanislaw Gruszka <sgruszka@...hat.com>
AuthorDate: Wed, 29 Jul 2009 12:15:28 +0200
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Mon, 3 Aug 2009 14:48:36 +0200

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@...hat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Acked-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
LKML-Reference: <1248862529-6063-4-git-send-email-sgruszka@...hat.com>
Signed-off-by: Ingo Molnar <mingo@...e.hu>


---
 kernel/posix-cpu-timers.c |   44 +++++++++++++++++++++++---------------------
 1 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index b60d644..69c9237 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;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/