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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: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik 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: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-63-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mel Gorman 2013-10-07 11:29:40 +01:00 committed by Ingo Molnar
parent de1c9ce6f0
commit 989348b5fc
1 changed files with 22 additions and 31 deletions
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53
kernel/sched/fair.c
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@ -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)
if (!p->numa_group || !p->numa_group->total_faults)
return 0;
total_faults = atomic_long_read(&p->numa_group->total_faults);
if (!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++;
@ -1543,15 +1535,15 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
if (!join)
return;
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]);
}
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);
for (i = 0; i < 2*nr_node_ids; i++) {
my_grp->faults[i] -= p->numa_faults[i];
grp->faults[i] += p->numa_faults[i];
}
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--;
grp->nr_tasks++;
@ -1571,12 +1563,11 @@ void task_numa_free(struct task_struct *p)
void *numa_faults = p->numa_faults;
if (grp) {
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);
spin_lock(&grp->lock);
for (i = 0; i < 2*nr_node_ids; i++)
grp->faults[i] -= p->numa_faults[i];
grp->total_faults -= p->total_numa_faults;
list_del(&p->numa_entry);
grp->nr_tasks--;
spin_unlock(&grp->lock);