Merge branch 'timers/nohz-posix-timers-v2' of... (a166fcf0) · Commits · e / devices / android_kernel_xiaomi_markw

include/linux/posix-timers.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -122,6 +122,8 @@ void run_posix_cpu_timers(struct task_struct *task);
		void posix_cpu_timers_exit(struct task_struct *task);
		void posix_cpu_timers_exit_group(struct task_struct *task);

		bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk);

		void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
		cputime_t newval, cputime_t oldval);

include/linux/tick.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -160,9 +160,13 @@ static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
		#ifdef CONFIG_NO_HZ_FULL
		extern void tick_nohz_init(void);
		extern int tick_nohz_full_cpu(int cpu);
		extern void tick_nohz_full_kick(void);
		extern void tick_nohz_full_kick_all(void);
		#else
		static inline void tick_nohz_init(void) { }
		static inline int tick_nohz_full_cpu(int cpu) { return 0; }
		static inline void tick_nohz_full_kick(void) { }
		static inline void tick_nohz_full_kick_all(void) { }
		#endif

kernel/posix-cpu-timers.c

+60 −16

Original line number	Diff line number	Diff line
		@@ -10,6 +10,8 @@
		#include <linux/kernel_stat.h>
		#include <trace/events/timer.h>
		#include <linux/random.h>
		#include <linux/tick.h>
		#include <linux/workqueue.h>

		/*
		* Called after updating RLIMIT_CPU to run cpu timer and update
		@@ -153,6 +155,21 @@ static void bump_cpu_timer(struct k_itimer *timer,
		}
		}

		/**
		* task_cputime_zero - Check a task_cputime struct for all zero fields.
		*
		* @cputime: The struct to compare.
		*
		* Checks @cputime to see if all fields are zero. Returns true if all fields
		* are zero, false if any field is nonzero.
		*/
		static inline int task_cputime_zero(const struct task_cputime *cputime)
		{
		if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
		return 1;
		return 0;
		}

		static inline cputime_t prof_ticks(struct task_struct *p)
		{
		cputime_t utime, stime;
		@@ -636,6 +653,37 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
		return 0;
		}

		#ifdef CONFIG_NO_HZ_FULL
		static void nohz_kick_work_fn(struct work_struct *work)
		{
		tick_nohz_full_kick_all();
		}

		static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);

		/*
		* We need the IPIs to be sent from sane process context.
		* The posix cpu timers are always set with irqs disabled.
		*/
		static void posix_cpu_timer_kick_nohz(void)
		{
		schedule_work(&nohz_kick_work);
		}

		bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
		{
		if (!task_cputime_zero(&tsk->cputime_expires))
		return true;

		if (tsk->signal->cputimer.running)
		return true;

		return false;
		}
		#else
		static inline void posix_cpu_timer_kick_nohz(void) { }
		#endif

		/*
		* Guts of sys_timer_settime for CPU timers.
		* This is called with the timer locked and interrupts disabled.
		@@ -794,6 +842,8 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
		sample_to_timespec(timer->it_clock,
		old_incr, &old->it_interval);
		}
		if (!ret)
		posix_cpu_timer_kick_nohz();
		return ret;
		}

		@@ -1008,21 +1058,6 @@ static void check_cpu_itimer(struct task_struct tsk, struct cpu_itimer it,
		}
		}

		/**
		* task_cputime_zero - Check a task_cputime struct for all zero fields.
		*
		* @cputime: The struct to compare.
		*
		* Checks @cputime to see if all fields are zero. Returns true if all fields
		* are zero, false if any field is nonzero.
		*/
		static inline int task_cputime_zero(const struct task_cputime *cputime)
		{
		if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
		return 1;
		return 0;
		}

		/*
		* Check for any per-thread CPU timers that have fired and move them
		* off the tsk->*_timers list onto the firing list. Per-thread timers
		@@ -1336,6 +1371,13 @@ void run_posix_cpu_timers(struct task_struct *tsk)
		cpu_timer_fire(timer);
		spin_unlock(&timer->it_lock);
		}

		/*
		* In case some timers were rescheduled after the queue got emptied,
		* wake up full dynticks CPUs.
		*/
		if (tsk->signal->cputimer.running)
		posix_cpu_timer_kick_nohz();
		}

		/*
		@@ -1366,7 +1408,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
		}

		if (!*newval)
		return;
		goto out;
		*newval += now.cpu;
		}

		@@ -1384,6 +1426,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
		tsk->signal->cputime_expires.virt_exp = *newval;
		break;
		}
		out:
		posix_cpu_timer_kick_nohz();
		}

		static int do_cpu_nanosleep(const clockid_t which_clock, int flags,

kernel/time/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -111,6 +111,7 @@ config NO_HZ_FULL
		select RCU_USER_QS
		select RCU_NOCB_CPU
		select CONTEXT_TRACKING_FORCE
		select IRQ_WORK
		help
		Adaptively try to shutdown the tick whenever possible, even when
		the CPU is running tasks. Typically this requires running a single

kernel/time/tick-sched.c

+51 −0

Original line number	Diff line number	Diff line
		@@ -147,6 +147,57 @@ static void tick_sched_handle(struct tick_sched ts, struct pt_regs regs)
		static cpumask_var_t nohz_full_mask;
		bool have_nohz_full_mask;

		/*
		* Re-evaluate the need for the tick on the current CPU
		* and restart it if necessary.
		*/
		static void tick_nohz_full_check(void)
		{
		/*
		* STUB for now, will be filled with the full tick stop/restart
		* infrastructure patches
		*/
		}

		static void nohz_full_kick_work_func(struct irq_work *work)
		{
		tick_nohz_full_check();
		}

		static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
		.func = nohz_full_kick_work_func,
		};

		/*
		* Kick the current CPU if it's full dynticks in order to force it to
		* re-evaluate its dependency on the tick and restart it if necessary.
		*/
		void tick_nohz_full_kick(void)
		{
		if (tick_nohz_full_cpu(smp_processor_id()))
		irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
		}

		static void nohz_full_kick_ipi(void *info)
		{
		tick_nohz_full_check();
		}

		/*
		* Kick all full dynticks CPUs in order to force these to re-evaluate
		* their dependency on the tick and restart it if necessary.
		*/
		void tick_nohz_full_kick_all(void)
		{
		if (!have_nohz_full_mask)
		return;

		preempt_disable();
		smp_call_function_many(nohz_full_mask,
		nohz_full_kick_ipi, NULL, false);
		preempt_enable();
		}

		int tick_nohz_full_cpu(int cpu)
		{
		if (!have_nohz_full_mask)