change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/kernel/time/tick-common.c
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@@ -1,15 +1,11 @@
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+// SPDX-License-Identifier: GPL-2.0
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 /*
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- * linux/kernel/time/tick-common.c
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- *
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  * This file contains the base functions to manage periodic tick
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  * related events.
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  *
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  * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
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  * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
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  * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
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- *
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- * This code is licenced under the GPL version 2. For details see
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- * kernel-base/COPYING.
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  */
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 #include <linux/cpu.h>
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 #include <linux/err.h>
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@@ -21,6 +17,7 @@
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 #include <linux/sched.h>
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 #include <linux/module.h>
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 #include <trace/events/power.h>
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+#include <trace/hooks/sched.h>
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 #include <asm/irq_regs.h>
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23
 
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@@ -34,7 +31,6 @@
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  * Tick next event: keeps track of the tick time
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  */
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 ktime_t tick_next_period;
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-ktime_t tick_period;
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 /*
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  * tick_do_timer_cpu is a timer core internal variable which holds the CPU NR
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@@ -51,6 +47,14 @@
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  *    procedure also covers cpu hotplug.
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  */
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 int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
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+#ifdef CONFIG_NO_HZ_FULL
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+/*
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+ * tick_do_timer_boot_cpu indicates the boot CPU temporarily owns
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+ * tick_do_timer_cpu and it should be taken over by an eligible secondary
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+ * when one comes online.
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+ */
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+static int tick_do_timer_boot_cpu __read_mostly = -1;
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+#endif
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 /*
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  * Debugging: see timer_list.c
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@@ -80,14 +84,17 @@
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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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+		tick_next_period = ktime_add_ns(tick_next_period, TICK_NSEC);
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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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 		update_wall_time();
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+		trace_android_vh_jiffies_update(NULL);
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 	}
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 	update_process_times(user_mode(get_irq_regs()));
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@@ -121,7 +128,7 @@
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 		 * Setup the next period for devices, which do not have
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 		 * periodic mode:
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 		 */
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-		next = ktime_add(next, tick_period);
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+		next = ktime_add_ns(next, TICK_NSEC);
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 		if (!clockevents_program_event(dev, next, false))
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 			return;
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@@ -154,23 +161,43 @@
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 	    !tick_broadcast_oneshot_active()) {
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 		clockevents_switch_state(dev, CLOCK_EVT_STATE_PERIODIC);
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 	} else {
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-		unsigned long seq;
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+		unsigned int seq;
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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_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
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 		for (;;) {
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 			if (!clockevents_program_event(dev, next, false))
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 				return;
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-			next = ktime_add(next, tick_period);
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+			next = ktime_add_ns(next, TICK_NSEC);
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 		}
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 	}
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 }
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+
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+#ifdef CONFIG_NO_HZ_FULL
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+static void giveup_do_timer(void *info)
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+{
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+	int cpu = *(unsigned int *)info;
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+
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+	WARN_ON(tick_do_timer_cpu != smp_processor_id());
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+
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+	tick_do_timer_cpu = cpu;
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+}
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+
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+static void tick_take_do_timer_from_boot(void)
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+{
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+	int cpu = smp_processor_id();
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+	int from = tick_do_timer_boot_cpu;
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+
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+	if (from >= 0 && from != cpu)
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+		smp_call_function_single(from, giveup_do_timer, &cpu, 1);
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+}
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+#endif
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 /*
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  * Setup the tick device
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@@ -191,12 +218,24 @@
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 		 * this cpu:
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 		 */
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 		if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
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-			if (!tick_nohz_full_cpu(cpu))
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-				tick_do_timer_cpu = cpu;
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-			else
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-				tick_do_timer_cpu = TICK_DO_TIMER_NONE;
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+			tick_do_timer_cpu = cpu;
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 			tick_next_period = ktime_get();
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-			tick_period = NSEC_PER_SEC / HZ;
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+#ifdef CONFIG_NO_HZ_FULL
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+			/*
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+			 * The boot CPU may be nohz_full, in which case set
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+			 * tick_do_timer_boot_cpu so the first housekeeping
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+			 * secondary that comes up will take do_timer from
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+			 * us.
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+			 */
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+			if (tick_nohz_full_cpu(cpu))
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+				tick_do_timer_boot_cpu = cpu;
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+
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+		} else if (tick_do_timer_boot_cpu != -1 &&
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+						!tick_nohz_full_cpu(cpu)) {
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+			tick_take_do_timer_from_boot();
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+			tick_do_timer_boot_cpu = -1;
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+			WARN_ON(tick_do_timer_cpu != cpu);
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+#endif
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 		}
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 		/*
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@@ -338,7 +377,7 @@
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 	/*
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 	 * Can the new device be used as a broadcast device ?
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 	 */
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-	tick_install_broadcast_device(newdev);
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+	tick_install_broadcast_device(newdev, cpu);
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 }
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 /**