Commit 5803ffa8 authored by Yipeng Zou's avatar Yipeng Zou
Browse files

smart_grid: introducing rebuild_affinity_domain 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9OJK9


CVE: NA

----------------------------------------

Here are many scenarios we tested with smart_grid, we found that the
first domain level is key to the benchmark.

The reason is that there are many things such as interrupt affinity,
memory affinity factor that can have a big impact on the test.

Before this patch, the first domain level is unchangeable after
creation.

This patch introduce the 'cpu.rebuild_affinity_domain' to dynamically
reconfigure all domain levels.

Typical use cases:

echo $cpu_id > cpu.rebuild_affinity_domain

The cpu_id means which cpu we want to set first level.

If we set cpu_id = 34, we can see some change like:

 ----------------                       -----------------
| level 0 (0-31) |                     | level 0 (32-63) |
 ----------------                       -----------------
         v                                   v
 -------------------                    ------------------
|  level 1 (0-63)   |                  |  level 1 (0-63)  |
 -------------------                    ------------------
           v                  -->              v
 ---------------------                  --------------------
|   level 2 (0-95)    |                |   level 2 (0-95)   |
 ---------------------                  --------------------
             v                                   v
 ------------------------               ----------------------
|    level 3 (0-127)     |             |    level 3 (0-127)   |
 ------------------------               ----------------------

There are number of constraints on the rebuild feature:

1. Only rebuild domain while auto mode disabled.
   (cpu.dynamic_affinity_mode == 1)
2. Only rebuild on active and housekeeping cpu.
   (Offline and isolate CPUs are forbidden)
3. This file is write only.

Signed-off-by: default avatarYipeng Zou <zouyipeng@huawei.com>
parent 34c4be6c

kernel/sched/core.c

+13 −0
Original line number Diff line number Diff line
@@ -9690,6 +9690,15 @@ static int cpu_affinity_stat_show(struct seq_file *sf, void *v) 


	return 0;

}



static int cpu_rebuild_affinity_domain_u64(struct cgroup_subsys_state *css,

					   struct cftype *cftype,

					   u64 cpu)

{

	struct task_group *tg = css_tg(css);



	return tg_rebuild_affinity_domains(cpu, tg->auto_affinity);

}

#endif /* CONFIG_QOS_SCHED_SMART_GRID */



#ifdef CONFIG_QOS_SCHED
@@ -9873,6 +9882,10 @@ static struct cftype cpu_legacy_files[] = { 
		.name = "affinity_stat",

		.seq_show = cpu_affinity_stat_show,

	},

	{

		.name = "rebuild_affinity_domain",

		.write_u64 = cpu_rebuild_affinity_domain_u64,

	},

#endif

#ifdef CONFIG_CFS_BANDWIDTH

	{

kernel/sched/fair.c

+43 −0
Original line number Diff line number Diff line
@@ -6242,6 +6242,49 @@ static void destroy_auto_affinity(struct task_group *tg) 
	kfree(tg->auto_affinity);

	tg->auto_affinity = NULL;

}



int tg_rebuild_affinity_domains(int cpu, struct auto_affinity *auto_affi)

{

	int ret = 0;

	int level = 0;

	struct sched_domain *tmp;



	if (unlikely(!auto_affi))

		return -EPERM;



	mutex_lock(&smart_grid_used_mutex);

	raw_spin_lock_irq(&auto_affi->lock);

	/* Only build domain while auto mode disabled */

	if (auto_affi->mode) {

		ret = -EPERM;

		goto unlock_all;

	}



	/* Only build on active and housekeeping cpu */

	if (!cpu_active(cpu) || !housekeeping_cpu(cpu, HK_FLAG_DOMAIN)) {

		ret = -EINVAL;

		goto unlock_all;

	}



	for_each_domain(cpu, tmp) {

		if (!auto_affi->ad.domains[level] || !auto_affi->ad.domains_orig[level])

			continue;



		/* rebuild domain[,_orig] and reset schedstat counter */

		cpumask_copy(auto_affi->ad.domains[level], sched_domain_span(tmp));

		cpumask_copy(auto_affi->ad.domains_orig[level], auto_affi->ad.domains[level]);

		__schedstat_set(auto_affi->ad.stay_cnt[level], 0);

		level++;

	}



	/* trigger to update smart grid zone */

	sched_grid_zone_update(false);



unlock_all:

	raw_spin_unlock_irq(&auto_affi->lock);

	mutex_unlock(&smart_grid_used_mutex);

	return ret;

}

#else

static void destroy_auto_affinity(struct task_group *tg) {}

kernel/sched/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -580,6 +580,7 @@ extern void start_auto_affinity(struct auto_affinity *auto_affi); 
extern void stop_auto_affinity(struct auto_affinity *auto_affi);

extern int init_auto_affinity(struct task_group *tg);

extern void tg_update_affinity_domains(int cpu, int online);

extern int tg_rebuild_affinity_domains(int cpu, struct auto_affinity *auto_affi);



#else

static inline int init_auto_affinity(struct task_group *tg)