linux-kernel - [tip: timers/core] posix-timers: Consolidate timer setup

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Message-ID: <172235918845.2215.1121030540824757359.tip-bot2@tip-bot2>
Date: Tue, 30 Jul 2024 17:06:28 -0000
From: "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
 Frederic Weisbecker <frederic@...nel.org>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: timers/core] posix-timers: Consolidate timer setup

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     20f13385b5836d00d64698748565fc6d3ce9b419
Gitweb:        https://git.kernel.org/tip/20f13385b5836d00d64698748565fc6d3ce9b419
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Mon, 10 Jun 2024 18:42:30 +02:00
Committer:     Frederic Weisbecker <frederic@...nel.org>
CommitterDate: Mon, 29 Jul 2024 21:57:35 +02:00

posix-timers: Consolidate timer setup

hrtimer based and CPU timers have their own way to install the new interval
and to reset overrun and signal handling related data.

Create a helper function and do the same operation for all variants.

This also makes the handling of the interval consistent. It's only stored
when the timer is actually armed, i.e. timer->it_value != 0. Before that it
was stored unconditionally for posix CPU timers and conditionally for the
other posix timers.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/time/posix-cpu-timers.c | 15 +--------------
 kernel/time/posix-timers.c     | 25 +++++++++++++++++++------
 kernel/time/posix-timers.h     |  1 +
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 4107977..43cf3f6 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -714,21 +714,8 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	}
 
 	unlock_task_sighand(p, &flags);
-	/*
-	 * Install the new reload setting, and
-	 * set up the signal and overrun bookkeeping.
-	 */
-	timer->it_interval = timespec64_to_ktime(new->it_interval);
 
-	/*
-	 * This acts as a modification timestamp for the timer,
-	 * so any automatic reload attempt will punt on seeing
-	 * that we have reset the timer manually.
-	 */
-	timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
-		~REQUEUE_PENDING;
-	timer->it_overrun_last = 0;
-	timer->it_overrun = -1;
+	posix_timer_set_common(timer, new);
 
 	/*
 	 * If the new expiry time was already in the past the timer was not
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index fa75e94..679be90 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -856,6 +856,23 @@ static struct k_itimer *timer_wait_running(struct k_itimer *timer,
 	return lock_timer(timer_id, flags);
 }
 
+/*
+ * Set up the new interval and reset the signal delivery data
+ */
+void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_setting)
+{
+	if (new_setting->it_value.tv_sec || new_setting->it_value.tv_nsec)
+		timer->it_interval = timespec64_to_ktime(new_setting->it_interval);
+	else
+		timer->it_interval = 0;
+
+	/* Prevent reloading in case there is a signal pending */
+	timer->it_requeue_pending = (timer->it_requeue_pending + 2) & ~REQUEUE_PENDING;
+	/* Reset overrun accounting */
+	timer->it_overrun_last = 0;
+	timer->it_overrun = -1LL;
+}
+
 /* Set a POSIX.1b interval timer. */
 int common_timer_set(struct k_itimer *timr, int flags,
 		     struct itimerspec64 *new_setting,
@@ -878,16 +895,12 @@ int common_timer_set(struct k_itimer *timr, int flags,
 		return TIMER_RETRY;
 
 	timr->it_active = 0;
-	timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
-		~REQUEUE_PENDING;
-	timr->it_overrun_last = 0;
-	timr->it_overrun = -1LL;
+	posix_timer_set_common(timr, new_setting);
 
-	/* Switch off the timer when it_value is zero */
+	/* Keep timer disarmed when it_value is zero */
 	if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
 		return 0;
 
-	timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
 	expires = timespec64_to_ktime(new_setting->it_value);
 	if (flags & TIMER_ABSTIME)
 		expires = timens_ktime_to_host(timr->it_clock, expires);
diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h
index f32a2eb..630a77b 100644
--- a/kernel/time/posix-timers.h
+++ b/kernel/time/posix-timers.h
@@ -42,4 +42,5 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting);
 int common_timer_set(struct k_itimer *timr, int flags,
 		     struct itimerspec64 *new_setting,
 		     struct itimerspec64 *old_setting);
+void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_setting);
 int common_timer_del(struct k_itimer *timer);