sched: revert the revert of: weight calculations (a7be37ac) · Commits · 戴 / test

kernel/sched.c

+3 −6

Original line number	Original line	Diff line number	Diff line
	@@ -1342,6 +1342,9 @@ static void __resched_task(struct task_struct *p, int tif_bit)
	*/		*/
	#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))		#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))

			/*
			* delta *= weight / lw
			*/
	static unsigned long		static unsigned long
	calc_delta_mine(unsigned long delta_exec, unsigned long weight,		calc_delta_mine(unsigned long delta_exec, unsigned long weight,
	struct load_weight *lw)		struct load_weight *lw)
	@@ -1369,12 +1372,6 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
	return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);		return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
	}		}

	static inline unsigned long
	calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
	{
	return calc_delta_mine(delta_exec, NICE_0_LOAD, lw);
	}

	static inline void update_load_add(struct load_weight *lw, unsigned long inc)		static inline void update_load_add(struct load_weight *lw, unsigned long inc)
	{		{
	lw->weight += inc;		lw->weight += inc;

kernel/sched_fair.c

+72 −33

Original line number	Original line	Diff line number	Diff line
	@@ -333,6 +333,34 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
	}		}
	#endif		#endif

			/*
			* delta *= w / rw
			*/
			static inline unsigned long
			calc_delta_weight(unsigned long delta, struct sched_entity *se)
			{
			for_each_sched_entity(se) {
			delta = calc_delta_mine(delta,
			se->load.weight, &cfs_rq_of(se)->load);
			}

			return delta;
			}

			/*
			* delta *= rw / w
			*/
			static inline unsigned long
			calc_delta_fair(unsigned long delta, struct sched_entity *se)
			{
			for_each_sched_entity(se) {
			delta = calc_delta_mine(delta,
			cfs_rq_of(se)->load.weight, &se->load);
			}

			return delta;
			}

	/*		/*
	* The idea is to set a period in which each task runs once.		* The idea is to set a period in which each task runs once.
	*		*
	@@ -362,47 +390,54 @@ static u64 __sched_period(unsigned long nr_running)
	*/		*/
	static u64 sched_slice(struct cfs_rq cfs_rq, struct sched_entity se)		static u64 sched_slice(struct cfs_rq cfs_rq, struct sched_entity se)
	{		{
	u64 slice = __sched_period(cfs_rq->nr_running);		return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);

	for_each_sched_entity(se) {
	cfs_rq = cfs_rq_of(se);

	slice *= se->load.weight;
	do_div(slice, cfs_rq->load.weight);
	}


	return slice;
	}		}

	/*		/*
	* We calculate the vruntime slice of a to be inserted task		* We calculate the vruntime slice of a to be inserted task
	*		*
	* vs = s/w = p/rw		* vs = s*rw/w = p
	*/		*/
	static u64 sched_vslice_add(struct cfs_rq cfs_rq, struct sched_entity se)		static u64 sched_vslice_add(struct cfs_rq cfs_rq, struct sched_entity se)
	{		{
	unsigned long nr_running = cfs_rq->nr_running;		unsigned long nr_running = cfs_rq->nr_running;
	unsigned long weight;
	u64 vslice;

	if (!se->on_rq)		if (!se->on_rq)
	nr_running++;		nr_running++;

	vslice = __sched_period(nr_running);		return __sched_period(nr_running);
			}

			/*
			* The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
			* that it favours >=0 over <0.
			*
			* -20 \|
			* \|
			* 0 --------+-------
			* .'
			* 19 .'
			*
			*/
			static unsigned long
			calc_delta_asym(unsigned long delta, struct sched_entity *se)
			{
			struct load_weight lw = {
			.weight = NICE_0_LOAD,
			.inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
			};

	for_each_sched_entity(se) {		for_each_sched_entity(se) {
	cfs_rq = cfs_rq_of(se);		struct load_weight *se_lw = &se->load;

	weight = cfs_rq->load.weight;		if (se->load.weight < NICE_0_LOAD)
	if (!se->on_rq)		se_lw = &lw;
	weight += se->load.weight;

	vslice *= NICE_0_LOAD;		delta = calc_delta_mine(delta,
	do_div(vslice, weight);		cfs_rq_of(se)->load.weight, se_lw);
	}		}

	return vslice;		return delta;
	}		}

	/*		/*
	@@ -419,11 +454,7 @@ __update_curr(struct cfs_rq cfs_rq, struct sched_entity curr,

	curr->sum_exec_runtime += delta_exec;		curr->sum_exec_runtime += delta_exec;
	schedstat_add(cfs_rq, exec_clock, delta_exec);		schedstat_add(cfs_rq, exec_clock, delta_exec);
	delta_exec_weighted = delta_exec;		delta_exec_weighted = calc_delta_fair(delta_exec, curr);
	if (unlikely(curr->load.weight != NICE_0_LOAD)) {
	delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
	&curr->load);
	}
	curr->vruntime += delta_exec_weighted;		curr->vruntime += delta_exec_weighted;
	}		}

	@@ -609,8 +640,17 @@ place_entity(struct cfs_rq cfs_rq, struct sched_entity se, int initial)

	if (!initial) {		if (!initial) {
	/* sleeps upto a single latency don't count. */		/* sleeps upto a single latency don't count. */
	if (sched_feat(NEW_FAIR_SLEEPERS))		if (sched_feat(NEW_FAIR_SLEEPERS)) {
	vruntime -= sysctl_sched_latency;		unsigned long thresh = sysctl_sched_latency;

			/*
			* convert the sleeper threshold into virtual time
			*/
			if (sched_feat(NORMALIZED_SLEEPER))
			thresh = calc_delta_fair(thresh, se);

			vruntime -= thresh;
			}

	/* ensure we never gain time by being placed backwards. */		/* ensure we never gain time by being placed backwards. */
	vruntime = max_vruntime(se->vruntime, vruntime);		vruntime = max_vruntime(se->vruntime, vruntime);
	@@ -1111,11 +1151,10 @@ static unsigned long wakeup_gran(struct sched_entity *se)
	unsigned long gran = sysctl_sched_wakeup_granularity;		unsigned long gran = sysctl_sched_wakeup_granularity;

	/*		/*
	* More easily preempt - nice tasks, while not making		* More easily preempt - nice tasks, while not making it harder for
	* it harder for + nice tasks.		* + nice tasks.
	*/		*/
	if (unlikely(se->load.weight > NICE_0_LOAD))		gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
	gran = calc_delta_fair(gran, &se->load);

	return gran;		return gran;
	}		}

kernel/sched_features.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)		SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
			SCHED_FEAT(NORMALIZED_SLEEPER, 1)
	SCHED_FEAT(WAKEUP_PREEMPT, 1)		SCHED_FEAT(WAKEUP_PREEMPT, 1)
	SCHED_FEAT(START_DEBIT, 1)		SCHED_FEAT(START_DEBIT, 1)
	SCHED_FEAT(AFFINE_WAKEUPS, 1)		SCHED_FEAT(AFFINE_WAKEUPS, 1)

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