160 lines
5.1 KiB
Diff
160 lines
5.1 KiB
Diff
Subject: timekeeping-split-jiffies-lock.patch
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Feb 2013 22:36:59 +0100
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patches-3.10.4-rt1.tar.xz
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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kernel/time/jiffies.c | 7 ++++---
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kernel/time/tick-common.c | 10 ++++++----
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kernel/time/tick-internal.h | 3 ++-
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kernel/time/tick-sched.c | 16 ++++++++++------
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kernel/time/timekeeping.c | 6 ++++--
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5 files changed, 26 insertions(+), 16 deletions(-)
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Index: linux-stable/kernel/time/jiffies.c
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===================================================================
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--- linux-stable.orig/kernel/time/jiffies.c
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+++ linux-stable/kernel/time/jiffies.c
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@@ -67,7 +67,8 @@ static struct clocksource clocksource_ji
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.shift = JIFFIES_SHIFT,
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};
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-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
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+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
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+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
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#if (BITS_PER_LONG < 64)
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u64 get_jiffies_64(void)
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@@ -76,9 +77,9 @@ u64 get_jiffies_64(void)
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u64 ret;
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do {
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- seq = read_seqbegin(&jiffies_lock);
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+ seq = read_seqcount_begin(&jiffies_seq);
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ret = jiffies_64;
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- } while (read_seqretry(&jiffies_lock, seq));
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+ } while (read_seqcount_retry(&jiffies_seq, seq));
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return ret;
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}
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EXPORT_SYMBOL(get_jiffies_64);
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Index: linux-stable/kernel/time/tick-common.c
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===================================================================
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--- linux-stable.orig/kernel/time/tick-common.c
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+++ linux-stable/kernel/time/tick-common.c
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@@ -63,13 +63,15 @@ int tick_is_oneshot_available(void)
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static void tick_periodic(int cpu)
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{
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if (tick_do_timer_cpu == cpu) {
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- write_seqlock(&jiffies_lock);
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+ raw_spin_lock(&jiffies_lock);
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+ write_seqcount_begin(&jiffies_seq);
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/* Keep track of the next tick event */
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tick_next_period = ktime_add(tick_next_period, tick_period);
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do_timer(1);
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- write_sequnlock(&jiffies_lock);
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+ write_seqcount_end(&jiffies_seq);
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+ raw_spin_unlock(&jiffies_lock);
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}
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update_process_times(user_mode(get_irq_regs()));
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@@ -130,9 +132,9 @@ void tick_setup_periodic(struct clock_ev
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ktime_t next;
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do {
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- seq = read_seqbegin(&jiffies_lock);
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+ seq = read_seqcount_begin(&jiffies_seq);
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next = tick_next_period;
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- } while (read_seqretry(&jiffies_lock, seq));
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+ } while (read_seqcount_retry(&jiffies_seq, seq));
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clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
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Index: linux-stable/kernel/time/tick-internal.h
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===================================================================
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--- linux-stable.orig/kernel/time/tick-internal.h
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+++ linux-stable/kernel/time/tick-internal.h
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@@ -4,7 +4,8 @@
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#include <linux/hrtimer.h>
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#include <linux/tick.h>
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-extern seqlock_t jiffies_lock;
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+extern raw_spinlock_t jiffies_lock;
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+extern seqcount_t jiffies_seq;
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#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
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Index: linux-stable/kernel/time/tick-sched.c
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===================================================================
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--- linux-stable.orig/kernel/time/tick-sched.c
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+++ linux-stable/kernel/time/tick-sched.c
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@@ -61,7 +61,8 @@ static void tick_do_update_jiffies64(kti
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return;
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/* Reevalute with jiffies_lock held */
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- write_seqlock(&jiffies_lock);
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+ raw_spin_lock(&jiffies_lock);
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+ write_seqcount_begin(&jiffies_seq);
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delta = ktime_sub(now, last_jiffies_update);
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if (delta.tv64 >= tick_period.tv64) {
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@@ -84,7 +85,8 @@ static void tick_do_update_jiffies64(kti
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/* Keep the tick_next_period variable up to date */
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tick_next_period = ktime_add(last_jiffies_update, tick_period);
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}
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- write_sequnlock(&jiffies_lock);
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+ write_seqcount_end(&jiffies_seq);
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+ raw_spin_unlock(&jiffies_lock);
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}
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/*
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@@ -94,12 +96,14 @@ static ktime_t tick_init_jiffy_update(vo
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{
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ktime_t period;
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- write_seqlock(&jiffies_lock);
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+ raw_spin_lock(&jiffies_lock);
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+ write_seqcount_begin(&jiffies_seq);
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/* Did we start the jiffies update yet ? */
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if (last_jiffies_update.tv64 == 0)
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last_jiffies_update = tick_next_period;
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period = last_jiffies_update;
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- write_sequnlock(&jiffies_lock);
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+ write_seqcount_end(&jiffies_seq);
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+ raw_spin_unlock(&jiffies_lock);
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return period;
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}
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@@ -547,11 +551,11 @@ static ktime_t tick_nohz_stop_sched_tick
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/* Read jiffies and the time when jiffies were updated last */
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do {
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- seq = read_seqbegin(&jiffies_lock);
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+ seq = read_seqcount_begin(&jiffies_seq);
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last_update = last_jiffies_update;
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last_jiffies = jiffies;
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time_delta = timekeeping_max_deferment();
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- } while (read_seqretry(&jiffies_lock, seq));
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+ } while (read_seqcount_retry(&jiffies_seq, seq));
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if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
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arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
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Index: linux-stable/kernel/time/timekeeping.c
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===================================================================
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--- linux-stable.orig/kernel/time/timekeeping.c
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+++ linux-stable/kernel/time/timekeeping.c
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@@ -1712,7 +1712,9 @@ EXPORT_SYMBOL(hardpps);
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*/
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void xtime_update(unsigned long ticks)
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{
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- write_seqlock(&jiffies_lock);
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+ raw_spin_lock(&jiffies_lock);
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+ write_seqcount_begin(&jiffies_seq);
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do_timer(ticks);
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- write_sequnlock(&jiffies_lock);
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+ write_seqcount_end(&jiffies_seq);
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+ raw_spin_unlock(&jiffies_lock);
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}
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