Commit 54a43d54 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds

numa: add a sysctl for numa_balancing

Add a working sysctl to enable/disable automatic numa memory balancing
at runtime.

This allows us to track down performance problems with this feature and
is generally a good idea.

This was possible earlier through debugfs, but only with special
debugging options set.  Also fix the boot message.

[akpm@linux-foundation.org: s/sched_numa_balancing/sysctl_numa_balancing/]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5e270e25
......@@ -99,4 +99,8 @@ extern int sched_rt_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
extern int sysctl_numa_balancing(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
#endif /* _SCHED_SYSCTL_H */
......@@ -1770,7 +1770,29 @@ void set_numabalancing_state(bool enabled)
numabalancing_enabled = enabled;
}
#endif /* CONFIG_SCHED_DEBUG */
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_PROC_SYSCTL
int sysctl_numa_balancing(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table t;
int err;
int state = numabalancing_enabled;
if (write && !capable(CAP_SYS_ADMIN))
return -EPERM;
t = *table;
t.data = &state;
err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
if (err < 0)
return err;
if (write)
set_numabalancing_state(state);
return err;
}
#endif
#endif
/*
* fork()/clone()-time setup:
......
......@@ -389,6 +389,15 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "numa_balancing",
.data = NULL, /* filled in by handler */
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = sysctl_numa_balancing,
.extra1 = &zero,
.extra2 = &one,
},
#endif /* CONFIG_NUMA_BALANCING */
#endif /* CONFIG_SCHED_DEBUG */
{
......
......@@ -2668,7 +2668,7 @@ static void __init check_numabalancing_enable(void)
if (nr_node_ids > 1 && !numabalancing_override) {
printk(KERN_INFO "Enabling automatic NUMA balancing. "
"Configure with numa_balancing= or sysctl");
"Configure with numa_balancing= or the kernel.numa_balancing sysctl");
set_numabalancing_state(numabalancing_default);
}
}
......
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