This patch adds Kconfig options and kernel parameters to allow the enabling and disabling of automatic NUMA balancing. The existance of such a switch was and is very important when debugging problems related to transparent hugepages and we should have the same for automatic NUMA placement.
Signed-off-by: Mel Gorman <[email protected]> --- Documentation/kernel-parameters.txt | 3 +++ include/linux/sched.h | 4 +++ init/Kconfig | 8 ++++++ kernel/sched/core.c | 48 ++++++++++++++++++++++++----------- kernel/sched/fair.c | 3 +++ kernel/sched/features.h | 6 +++-- mm/mempolicy.c | 46 +++++++++++++++++++++++++++++++++ 7 files changed, 101 insertions(+), 17 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9776f06..d984acb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -403,6 +403,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. atkbd.softrepeat= [HW] Use software keyboard repeat + balancenuma= [KNL,X86] Enable or disable automatic NUMA balancing. + Allowed values are enable and disable + baycom_epp= [HW,AX25] Format: <io>,<mode> diff --git a/include/linux/sched.h b/include/linux/sched.h index 1068afd..2669bdd 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1563,10 +1563,14 @@ struct task_struct { #ifdef CONFIG_BALANCE_NUMA extern void task_numa_fault(int node, int pages, bool migrated); +extern void set_balancenuma_state(bool enabled); #else static inline void task_numa_fault(int node, int pages, bool migrated) { } +static inline void set_balancenuma_state(bool enabled) +{ +} #endif /* diff --git a/init/Kconfig b/init/Kconfig index 6897a05..4cccc00f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -720,6 +720,14 @@ config ARCH_USES_NUMA_PROT_NONE depends on ARCH_WANTS_PROT_NUMA_PROT_NONE depends on BALANCE_NUMA +config BALANCE_NUMA_DEFAULT_ENABLED + bool "Automatically enable NUMA aware memory/task placement" + default y + depends on BALANCE_NUMA + help + If set, autonumic NUMA balancing will be enabled if running on a NUMA + machine. + config BALANCE_NUMA bool "Memory placement aware NUMA scheduler" default n diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a59d869..4841f4f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -192,23 +192,10 @@ static void sched_feat_disable(int i) { }; static void sched_feat_enable(int i) { }; #endif /* HAVE_JUMP_LABEL */ -static ssize_t -sched_feat_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) +static int sched_feat_set(char *cmp) { - char buf[64]; - char *cmp; - int neg = 0; int i; - - if (cnt > 63) - cnt = 63; - - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - - buf[cnt] = 0; - cmp = strstrip(buf); + int neg = 0; if (strncmp(cmp, "NO_", 3) == 0) { neg = 1; @@ -228,6 +215,27 @@ sched_feat_write(struct file *filp, const char __user *ubuf, } } + return i; +} + +static ssize_t +sched_feat_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[64]; + char *cmp; + int i; + + if (cnt > 63) + cnt = 63; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + cmp = strstrip(buf); + + i = sched_feat_set(cmp); if (i == __SCHED_FEAT_NR) return -EINVAL; @@ -1549,6 +1557,16 @@ static void __sched_fork(struct task_struct *p) #endif /* CONFIG_BALANCE_NUMA */ } +#ifdef CONFIG_BALANCE_NUMA +void set_balancenuma_state(bool enabled) +{ + if (enabled) + sched_feat_set("NUMA"); + else + sched_feat_set("NO_NUMA"); +} +#endif /* CONFIG_BALANCE_NUMA */ + /* * fork()/clone()-time setup: */ diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c1be907..b4bc459 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -811,6 +811,9 @@ void task_numa_fault(int node, int pages, bool migrated) { struct task_struct *p = current; + if (!sched_feat_numa(NUMA)) + return; + /* FIXME: Allocate task-specific structure for placement policy here */ /* diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 7cfd289..d402368 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -63,8 +63,10 @@ SCHED_FEAT(RT_RUNTIME_SHARE, true) SCHED_FEAT(LB_MIN, false) /* - * Apply the automatic NUMA scheduling policy + * Apply the automatic NUMA scheduling policy. Enabled automatically + * at runtime if running on a NUMA machine. Can be controlled via + * balancenuma= */ #ifdef CONFIG_BALANCE_NUMA -SCHED_FEAT(NUMA, true) +SCHED_FEAT(NUMA, false) #endif diff --git a/mm/mempolicy.c b/mm/mempolicy.c index fd20e28..56ad9bf 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2521,6 +2521,50 @@ void mpol_free_shared_policy(struct shared_policy *p) mutex_unlock(&p->mutex); } +#ifdef CONFIG_BALANCE_NUMA +static bool __initdata balancenuma_override; + +static void __init check_balancenuma_enable(void) +{ + bool balancenuma_default = false; + + if (IS_ENABLED(CONFIG_BALANCE_NUMA_DEFAULT_ENABLED)) + balancenuma_default = true; + + if (nr_node_ids > 1 && !balancenuma_override) { + printk(KERN_INFO "Enabling automatic NUMA balancing. " + "Configure with balancenuma= or sysctl"); + set_balancenuma_state(balancenuma_default); + } +} + +static int __init setup_balancenuma(char *str) +{ + int ret = 0; + if (!str) + goto out; + balancenuma_override = true; + + if (!strcmp(str, "enable")) { + set_balancenuma_state(true); + ret = 1; + } else if (!strcmp(str, "disable")) { + set_balancenuma_state(false); + ret = 1; + } +out: + if (!ret) + printk(KERN_WARNING "Unable to parse balancenuma=\n"); + + return ret; +} +__setup("balancenuma=", setup_balancenuma); +#else +static inline void __init check_balancenuma_enable(void) +{ +} +#endif /* CONFIG_BALANCE_NUMA */ + /* assumes fs == KERNEL_DS */ void __init numa_policy_init(void) { @@ -2571,6 +2615,8 @@ void __init numa_policy_init(void) if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) printk("numa_policy_init: interleaving failed\n"); + + check_balancenuma_enable(); } /* Reset policy of current process to default */ -- 1.7.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
