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authorAndi Kleen <ak@linux.intel.com>2014-01-23 15:53:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:51 -0800
commit54a43d54988a3731d644fdeb7a1d6f46b4ac64c7 (patch)
tree87dc618d08b23d042e3ea01b3acbc56a0358cbdb
parent5e270e254885893f8c82ab9b91caa648af3690df (diff)
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: Andi Kleen <ak@linux.intel.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/sched/sysctl.h4
-rw-r--r--kernel/sched/core.c24
-rw-r--r--kernel/sysctl.c9
-rw-r--r--mm/mempolicy.c2
4 files changed, 37 insertions, 2 deletions
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 31e0193cb0c5..b13cf430764f 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -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 */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4d6964e49711..7fea865a810d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -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:
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 332cefcdb04b..693eac39c202 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -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 */
{
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0cd2c4d4e270..947293e76533 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -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);
}
}