Commit 989348b5 authored by Mel Gorman's avatar Mel Gorman Committed by Ingo Molnar
Browse files

sched/numa: Use unsigned longs for numa group fault stats 



As Peter says "If you're going to hold locks you can also do away with all
that atomic_long_*() nonsense". Lock aquisition moved slightly to protect
the updates.

Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-63-git-send-email-mgorman@suse.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent de1c9ce6

kernel/sched/fair.c

+20 −29
Original line number Diff line number Diff line
@@ -916,8 +916,8 @@ struct numa_group { 
	struct list_head task_list;



	struct rcu_head rcu;

	atomic_long_t total_faults;

	atomic_long_t faults[0];

	unsigned long total_faults;

	unsigned long faults[0];

};



pid_t task_numa_group_id(struct task_struct *p)
@@ -944,8 +944,7 @@ static inline unsigned long group_faults(struct task_struct *p, int nid) 
	if (!p->numa_group)

		return 0;



	return atomic_long_read(&p->numa_group->faults[2*nid]) +

	       atomic_long_read(&p->numa_group->faults[2*nid+1]);

	return p->numa_group->faults[2*nid] + p->numa_group->faults[2*nid+1];

}



/*
@@ -971,17 +970,10 @@ static inline unsigned long task_weight(struct task_struct *p, int nid) 


static inline unsigned long group_weight(struct task_struct *p, int nid)

{

	unsigned long total_faults;



	if (!p->numa_group)

		return 0;



	total_faults = atomic_long_read(&p->numa_group->total_faults);



	if (!total_faults)

	if (!p->numa_group || !p->numa_group->total_faults)

		return 0;



	return 1000 * group_faults(p, nid) / total_faults;

	return 1000 * group_faults(p, nid) / p->numa_group->total_faults;

}



static unsigned long weighted_cpuload(const int cpu);
@@ -1397,9 +1389,9 @@ static void task_numa_placement(struct task_struct *p) 
			p->total_numa_faults += diff;

			if (p->numa_group) {

				/* safe because we can only change our own group */

				atomic_long_add(diff, &p->numa_group->faults[i]);

				atomic_long_add(diff, &p->numa_group->total_faults);

				group_faults += atomic_long_read(&p->numa_group->faults[i]);

				p->numa_group->faults[i] += diff;

				p->numa_group->total_faults += diff;

				group_faults += p->numa_group->faults[i];

			}

		}
@@ -1475,7 +1467,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, 


	if (unlikely(!p->numa_group)) {

		unsigned int size = sizeof(struct numa_group) +

				    2*nr_node_ids*sizeof(atomic_long_t);

				    2*nr_node_ids*sizeof(unsigned long);



		grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);

		if (!grp)
@@ -1487,9 +1479,9 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, 
		grp->gid = p->pid;



		for (i = 0; i < 2*nr_node_ids; i++)

			atomic_long_set(&grp->faults[i], p->numa_faults[i]);

			grp->faults[i] = p->numa_faults[i];



		atomic_long_set(&grp->total_faults, p->total_numa_faults);

		grp->total_faults = p->total_numa_faults;



		list_add(&p->numa_entry, &grp->task_list);

		grp->nr_tasks++;
@@ -1543,14 +1535,14 @@ unlock: 
	if (!join)

		return;



	double_lock(&my_grp->lock, &grp->lock);



	for (i = 0; i < 2*nr_node_ids; i++) {

		atomic_long_sub(p->numa_faults[i], &my_grp->faults[i]);

		atomic_long_add(p->numa_faults[i], &grp->faults[i]);

		my_grp->faults[i] -= p->numa_faults[i];

		grp->faults[i] += p->numa_faults[i];

	}

	atomic_long_sub(p->total_numa_faults, &my_grp->total_faults);

	atomic_long_add(p->total_numa_faults, &grp->total_faults);



	double_lock(&my_grp->lock, &grp->lock);

	my_grp->total_faults -= p->total_numa_faults;

	grp->total_faults += p->total_numa_faults;



	list_move(&p->numa_entry, &grp->task_list);

	my_grp->nr_tasks--;
@@ -1571,12 +1563,11 @@ void task_numa_free(struct task_struct *p) 
	void *numa_faults = p->numa_faults;



	if (grp) {

		spin_lock(&grp->lock);

		for (i = 0; i < 2*nr_node_ids; i++)

			atomic_long_sub(p->numa_faults[i], &grp->faults[i]);



		atomic_long_sub(p->total_numa_faults, &grp->total_faults);

			grp->faults[i] -= p->numa_faults[i];

		grp->total_faults -= p->total_numa_faults;



		spin_lock(&grp->lock);

		list_del(&p->numa_entry);

		grp->nr_tasks--;

		spin_unlock(&grp->lock);

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