From 54a43d54988a3731d644fdeb7a1d6f46b4ac64c7 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 23 Jan 2014 15:53:13 -0800 Subject: [PATCH] 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 Acked-by: Mel Gorman Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sched/sysctl.h | 4 ++++ kernel/sched/core.c | 24 +++++++++++++++++++++++- kernel/sysctl.c | 9 +++++++++ mm/mempolicy.c | 2 +- 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); } }