Re: [PATCH 5/6] hugetlb: add per node hstate attributes

[Mel Gorman <mel@csn.ul.ie>]

On Wed, Sep 09, 2009 at 12:31:58PM -0400, Lee Schermerhorn wrote:
> [PATCH 5/6] hugetlb:  register per node hugepages attributes
> 
> V6:  + Use NUMA_NO_NODE for unspecified node id throughout hugetlb.c
>        to indicate that we didn't get there via a per node attribute.
>        Drop redundant "NO_NODEID_SPECIFIED" definition.
>      + handle movement of defaulting of nodes_allowed up to
>        set_max_huge_pages()
> 

ppc64 doesn't define NUMA_NO_NODE so this fails to build. Maybe move the
definition to include/linux/node.h as a pre-requisite patch?

> This patch adds the per huge page size control/query attributes
> to the per node sysdevs:
> 
> /sys/devices/system/node/node<ID>/hugepages/hugepages-<size>/
> 	nr_hugepages       - r/w
> 	free_huge_pages    - r/o
> 	surplus_huge_pages - r/o
> 
> The patch attempts to re-use/share as much of the existing
> global hstate attribute initialization and handling, and the
> "nodes_allowed" constraint processing as possible.
> Calling set_max_huge_pages() with no node indicates a change to
> global hstate parameters.  In this case, any non-default task
> mempolicy will be used to generate the nodes_allowed mask.  A
> valid node id indicates an update to that node's hstate 
> parameters, and the count argument specifies the target count
> for the specified node.  From this info, we compute the target
> global count for the hstate and construct a nodes_allowed node
> mask contain only the specified node.
> 
> Setting the node specific nr_hugepages via the per node attribute
> effectively ignores any task mempolicy or cpuset constraints.
> 
> With this patch:
> 
> (me):ls /sys/devices/system/node/node0/hugepages/hugepages-2048kB
> ./  ../  free_hugepages  nr_hugepages  surplus_hugepages
> 
> Starting from:
> Node 0 HugePages_Total:     0
> Node 0 HugePages_Free:      0
> Node 0 HugePages_Surp:      0
> Node 1 HugePages_Total:     0
> Node 1 HugePages_Free:      0
> Node 1 HugePages_Surp:      0
> Node 2 HugePages_Total:     0
> Node 2 HugePages_Free:      0
> Node 2 HugePages_Surp:      0
> Node 3 HugePages_Total:     0
> Node 3 HugePages_Free:      0
> Node 3 HugePages_Surp:      0
> vm.nr_hugepages = 0
> 
> Allocate 16 persistent huge pages on node 2:
> (me):echo 16 >/sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages
> 
> [Note that this is equivalent to:
> 	numactl -m 2 hugeadmin --pool-pages-min 2M:+16
> ]
> 
> Yields:
> Node 0 HugePages_Total:     0
> Node 0 HugePages_Free:      0
> Node 0 HugePages_Surp:      0
> Node 1 HugePages_Total:     0
> Node 1 HugePages_Free:      0
> Node 1 HugePages_Surp:      0
> Node 2 HugePages_Total:    16
> Node 2 HugePages_Free:     16
> Node 2 HugePages_Surp:      0
> Node 3 HugePages_Total:     0
> Node 3 HugePages_Free:      0
> Node 3 HugePages_Surp:      0
> vm.nr_hugepages = 16
> 
> Global controls work as expected--reduce pool to 8 persistent huge pages:
> (me):echo 8 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
> 
> Node 0 HugePages_Total:     0
> Node 0 HugePages_Free:      0
> Node 0 HugePages_Surp:      0
> Node 1 HugePages_Total:     0
> Node 1 HugePages_Free:      0
> Node 1 HugePages_Surp:      0
> Node 2 HugePages_Total:     8
> Node 2 HugePages_Free:      8
> Node 2 HugePages_Surp:      0
> Node 3 HugePages_Total:     0
> Node 3 HugePages_Free:      0
> Node 3 HugePages_Surp:      0
> 
> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
> Acked-by: Mel Gorman <mel@csn.ul.ie>
> 
>  drivers/base/node.c  |   33 +++++++
>  include/linux/node.h |    8 +
>  mm/hugetlb.c         |  240 ++++++++++++++++++++++++++++++++++++++++++++-------
>  3 files changed, 251 insertions(+), 30 deletions(-)
> 
> Index: linux-2.6.31-rc7-mmotm-090827-1651/drivers/base/node.c
> ===================================================================
> --- linux-2.6.31-rc7-mmotm-090827-1651.orig/drivers/base/node.c	2009-09-09 11:57:26.000000000 -0400
> +++ linux-2.6.31-rc7-mmotm-090827-1651/drivers/base/node.c	2009-09-09 11:57:37.000000000 -0400
> @@ -177,6 +177,37 @@ static ssize_t node_read_distance(struct
>  }
>  static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
>  
> +/*
> + * hugetlbfs per node attributes registration interface:
> + * When/if hugetlb[fs] subsystem initializes [sometime after this module],
> + * it will register it's per node attributes for all nodes on-line at that
> + * point.  It will also call register_hugetlbfs_with_node(), below, to
> + * register it's attribute registration functions with this node driver.
> + * Once these hooks have been initialized, the node driver will call into
> + * the hugetlb module to [un]register attributes for hot-plugged nodes.
> + */
> +NODE_REGISTRATION_FUNC __hugetlb_register_node;
> +NODE_REGISTRATION_FUNC __hugetlb_unregister_node;
> +
> +static inline void hugetlb_register_node(struct node *node)
> +{
> +	if (__hugetlb_register_node)
> +		__hugetlb_register_node(node);
> +}
> +
> +static inline void hugetlb_unregister_node(struct node *node)
> +{
> +	if (__hugetlb_unregister_node)
> +		__hugetlb_unregister_node(node);
> +}
> +
> +void register_hugetlbfs_with_node(NODE_REGISTRATION_FUNC doregister,
> +				  NODE_REGISTRATION_FUNC unregister)
> +{
> +	__hugetlb_register_node   = doregister;
> +	__hugetlb_unregister_node = unregister;
> +}
> +
>  
>  /*
>   * register_node - Setup a sysfs device for a node.
> @@ -200,6 +231,7 @@ int register_node(struct node *node, int
>  		sysdev_create_file(&node->sysdev, &attr_distance);
>  
>  		scan_unevictable_register_node(node);
> +		hugetlb_register_node(node);
>  	}
>  	return error;
>  }
> @@ -220,6 +252,7 @@ void unregister_node(struct node *node)
>  	sysdev_remove_file(&node->sysdev, &attr_distance);
>  
>  	scan_unevictable_unregister_node(node);
> +	hugetlb_unregister_node(node);
>  
>  	sysdev_unregister(&node->sysdev);
>  }
> Index: linux-2.6.31-rc7-mmotm-090827-1651/mm/hugetlb.c
> ===================================================================
> --- linux-2.6.31-rc7-mmotm-090827-1651.orig/mm/hugetlb.c	2009-09-09 11:57:36.000000000 -0400
> +++ linux-2.6.31-rc7-mmotm-090827-1651/mm/hugetlb.c	2009-09-09 11:57:37.000000000 -0400
> @@ -24,6 +24,7 @@
>  #include <asm/io.h>
>  
>  #include <linux/hugetlb.h>
> +#include <linux/node.h>
>  #include "internal.h"
>  
>  const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
> @@ -1243,7 +1244,8 @@ static int adjust_pool_surplus(struct hs
>  }
>  
>  #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
> -static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
> +static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
> +								int nid)
>  {
>  	unsigned long min_count, ret;
>  	nodemask_t *nodes_allowed;
> @@ -1251,7 +1253,17 @@ static unsigned long set_max_huge_pages(
>  	if (h->order >= MAX_ORDER)
>  		return h->max_huge_pages;
>  
> -	nodes_allowed = alloc_nodemask_of_mempolicy();
> +	if (nid == NUMA_NO_NODE) {
> +		nodes_allowed = alloc_nodemask_of_mempolicy();
> +	} else {
> +		/*
> +		 * incoming 'count' is for node 'nid' only, so
> +		 * adjust count to global, but restrict alloc/free
> +		 * to the specified node.
> +		 */
> +		count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
> +		nodes_allowed = alloc_nodemask_of_node(nid);
> +	}
>  	if (!nodes_allowed) {
>  		printk(KERN_WARNING "%s unable to allocate nodes allowed mask "
>  			"for huge page allocation.  Falling back to default.\n",
> @@ -1334,51 +1346,71 @@ out:
>  static struct kobject *hugepages_kobj;
>  static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
>  
> -static struct hstate *kobj_to_hstate(struct kobject *kobj)
> +static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);
> +
> +static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
>  {
>  	int i;
> +
>  	for (i = 0; i < HUGE_MAX_HSTATE; i++)
> -		if (hstate_kobjs[i] == kobj)
> +		if (hstate_kobjs[i] == kobj) {
> +			if (nidp)
> +				*nidp = NUMA_NO_NODE;
>  			return &hstates[i];
> -	BUG();
> -	return NULL;
> +		}
> +
> +	return kobj_to_node_hstate(kobj, nidp);
>  }
>  
>  static ssize_t nr_hugepages_show(struct kobject *kobj,
>  					struct kobj_attribute *attr, char *buf)
>  {
> -	struct hstate *h = kobj_to_hstate(kobj);
> -	return sprintf(buf, "%lu\n", h->nr_huge_pages);
> +	struct hstate *h;
> +	unsigned long nr_huge_pages;
> +	int nid;
> +
> +	h = kobj_to_hstate(kobj, &nid);
> +	if (nid == NUMA_NO_NODE)
> +		nr_huge_pages = h->nr_huge_pages;
> +	else
> +		nr_huge_pages = h->nr_huge_pages_node[nid];
> +
> +	return sprintf(buf, "%lu\n", nr_huge_pages);
>  }
> +
>  static ssize_t nr_hugepages_store(struct kobject *kobj,
> -		struct kobj_attribute *attr, const char *buf, size_t count)
> +		struct kobj_attribute *attr, const char *buf, size_t len)
>  {
> +	unsigned long count;
> +	struct hstate *h;
> +	int nid;
>  	int err;
> -	unsigned long input;
> -	struct hstate *h = kobj_to_hstate(kobj);
>  
> -	err = strict_strtoul(buf, 10, &input);
> +	err = strict_strtoul(buf, 10, &count);
>  	if (err)
>  		return 0;
>  
> -	h->max_huge_pages = set_max_huge_pages(h, input);
> +	h = kobj_to_hstate(kobj, &nid);
> +	h->max_huge_pages = set_max_huge_pages(h, count, nid);
>  
> -	return count;
> +	return len;
>  }
>  HSTATE_ATTR(nr_hugepages);
>  
>  static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
>  					struct kobj_attribute *attr, char *buf)
>  {
> -	struct hstate *h = kobj_to_hstate(kobj);
> +	struct hstate *h = kobj_to_hstate(kobj, NULL);
> +
>  	return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
>  }
> +
>  static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
>  		struct kobj_attribute *attr, const char *buf, size_t count)
>  {
>  	int err;
>  	unsigned long input;
> -	struct hstate *h = kobj_to_hstate(kobj);
> +	struct hstate *h = kobj_to_hstate(kobj, NULL);
>  
>  	err = strict_strtoul(buf, 10, &input);
>  	if (err)
> @@ -1395,15 +1427,24 @@ HSTATE_ATTR(nr_overcommit_hugepages);
>  static ssize_t free_hugepages_show(struct kobject *kobj,
>  					struct kobj_attribute *attr, char *buf)
>  {
> -	struct hstate *h = kobj_to_hstate(kobj);
> -	return sprintf(buf, "%lu\n", h->free_huge_pages);
> +	struct hstate *h;
> +	unsigned long free_huge_pages;
> +	int nid;
> +
> +	h = kobj_to_hstate(kobj, &nid);
> +	if (nid == NUMA_NO_NODE)
> +		free_huge_pages = h->free_huge_pages;
> +	else
> +		free_huge_pages = h->free_huge_pages_node[nid];
> +
> +	return sprintf(buf, "%lu\n", free_huge_pages);
>  }
>  HSTATE_ATTR_RO(free_hugepages);
>  
>  static ssize_t resv_hugepages_show(struct kobject *kobj,
>  					struct kobj_attribute *attr, char *buf)
>  {
> -	struct hstate *h = kobj_to_hstate(kobj);
> +	struct hstate *h = kobj_to_hstate(kobj, NULL);
>  	return sprintf(buf, "%lu\n", h->resv_huge_pages);
>  }
>  HSTATE_ATTR_RO(resv_hugepages);
> @@ -1411,8 +1452,17 @@ HSTATE_ATTR_RO(resv_hugepages);
>  static ssize_t surplus_hugepages_show(struct kobject *kobj,
>  					struct kobj_attribute *attr, char *buf)
>  {
> -	struct hstate *h = kobj_to_hstate(kobj);
> -	return sprintf(buf, "%lu\n", h->surplus_huge_pages);
> +	struct hstate *h;
> +	unsigned long surplus_huge_pages;
> +	int nid;
> +
> +	h = kobj_to_hstate(kobj, &nid);
> +	if (nid == NUMA_NO_NODE)
> +		surplus_huge_pages = h->surplus_huge_pages;
> +	else
> +		surplus_huge_pages = h->surplus_huge_pages_node[nid];
> +
> +	return sprintf(buf, "%lu\n", surplus_huge_pages);
>  }
>  HSTATE_ATTR_RO(surplus_hugepages);
>  
> @@ -1429,19 +1479,21 @@ static struct attribute_group hstate_att
>  	.attrs = hstate_attrs,
>  };
>  
> -static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
> +static int __init hugetlb_sysfs_add_hstate(struct hstate *h,
> +				struct kobject *parent,
> +				struct kobject **hstate_kobjs,
> +				struct attribute_group *hstate_attr_group)
>  {
>  	int retval;
> +	int hi = h - hstates;
>  
> -	hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
> -							hugepages_kobj);
> -	if (!hstate_kobjs[h - hstates])
> +	hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
> +	if (!hstate_kobjs[hi])
>  		return -ENOMEM;
>  
> -	retval = sysfs_create_group(hstate_kobjs[h - hstates],
> -							&hstate_attr_group);
> +	retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
>  	if (retval)
> -		kobject_put(hstate_kobjs[h - hstates]);
> +		kobject_put(hstate_kobjs[hi]);
>  
>  	return retval;
>  }
> @@ -1456,17 +1508,143 @@ static void __init hugetlb_sysfs_init(vo
>  		return;
>  
>  	for_each_hstate(h) {
> -		err = hugetlb_sysfs_add_hstate(h);
> +		err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
> +					 hstate_kobjs, &hstate_attr_group);
>  		if (err)
>  			printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
>  								h->name);
>  	}
>  }
>  
> +#ifdef CONFIG_NUMA
> +
> +struct node_hstate {
> +	struct kobject		*hugepages_kobj;
> +	struct kobject		*hstate_kobjs[HUGE_MAX_HSTATE];
> +};
> +struct node_hstate node_hstates[MAX_NUMNODES];
> +
> +static struct attribute *per_node_hstate_attrs[] = {
> +	&nr_hugepages_attr.attr,
> +	&free_hugepages_attr.attr,
> +	&surplus_hugepages_attr.attr,
> +	NULL,
> +};
> +
> +static struct attribute_group per_node_hstate_attr_group = {
> +	.attrs = per_node_hstate_attrs,
> +};
> +
> +static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
> +{
> +	int nid;
> +
> +	for (nid = 0; nid < nr_node_ids; nid++) {
> +		struct node_hstate *nhs = &node_hstates[nid];
> +		int i;
> +		for (i = 0; i < HUGE_MAX_HSTATE; i++)
> +			if (nhs->hstate_kobjs[i] == kobj) {
> +				if (nidp)
> +					*nidp = nid;
> +				return &hstates[i];
> +			}
> +	}
> +
> +	BUG();
> +	return NULL;
> +}
> +
> +void hugetlb_unregister_node(struct node *node)
> +{
> +	struct hstate *h;
> +	struct node_hstate *nhs = &node_hstates[node->sysdev.id];
> +
> +	if (!nhs->hugepages_kobj)
> +		return;
> +
> +	for_each_hstate(h)
> +		if (nhs->hstate_kobjs[h - hstates]) {
> +			kobject_put(nhs->hstate_kobjs[h - hstates]);
> +			nhs->hstate_kobjs[h - hstates] = NULL;
> +		}
> +
> +	kobject_put(nhs->hugepages_kobj);
> +	nhs->hugepages_kobj = NULL;
> +}
> +
> +static void hugetlb_unregister_all_nodes(void)
> +{
> +	int nid;
> +
> +	for (nid = 0; nid < nr_node_ids; nid++)
> +		hugetlb_unregister_node(&node_devices[nid]);
> +
> +	register_hugetlbfs_with_node(NULL, NULL);
> +}
> +
> +void hugetlb_register_node(struct node *node)
> +{
> +	struct hstate *h;
> +	struct node_hstate *nhs = &node_hstates[node->sysdev.id];
> +	int err;
> +
> +	if (nhs->hugepages_kobj)
> +		return;		/* already allocated */
> +
> +	nhs->hugepages_kobj = kobject_create_and_add("hugepages",
> +							&node->sysdev.kobj);
> +	if (!nhs->hugepages_kobj)
> +		return;
> +
> +	for_each_hstate(h) {
> +		err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
> +						nhs->hstate_kobjs,
> +						&per_node_hstate_attr_group);
> +		if (err) {
> +			printk(KERN_ERR "Hugetlb: Unable to add hstate %s"
> +					" for node %d\n",
> +						h->name, node->sysdev.id);
> +			hugetlb_unregister_node(node);
> +			break;
> +		}
> +	}
> +}
> +
> +static void hugetlb_register_all_nodes(void)
> +{
> +	int nid;
> +
> +	for (nid = 0; nid < nr_node_ids; nid++) {
> +		struct node *node = &node_devices[nid];
> +		if (node->sysdev.id == nid)
> +			hugetlb_register_node(node);
> +	}
> +
> +	register_hugetlbfs_with_node(hugetlb_register_node,
> +				     hugetlb_unregister_node);
> +}
> +#else	/* !CONFIG_NUMA */
> +
> +static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
> +{
> +	BUG();
> +	if (nidp)
> +		*nidp = -1;
> +	return NULL;
> +}
> +
> +static void hugetlb_unregister_all_nodes(void) { }
> +
> +static void hugetlb_register_all_nodes(void) { }
> +
> +#endif
> +
>  static void __exit hugetlb_exit(void)
>  {
>  	struct hstate *h;
>  
> +	hugetlb_unregister_all_nodes();
> +
>  	for_each_hstate(h) {
>  		kobject_put(hstate_kobjs[h - hstates]);
>  	}
> @@ -1501,6 +1679,8 @@ static int __init hugetlb_init(void)
>  
>  	hugetlb_sysfs_init();
>  
> +	hugetlb_register_all_nodes();
> +
>  	return 0;
>  }
>  module_init(hugetlb_init);
> @@ -1603,7 +1783,7 @@ int hugetlb_sysctl_handler(struct ctl_ta
>  	proc_doulongvec_minmax(table, write, buffer, length, ppos);
>  
>  	if (write)
> -		h->max_huge_pages = set_max_huge_pages(h, tmp);
> +		h->max_huge_pages = set_max_huge_pages(h, tmp, NUMA_NO_NODE);
>  
>  	return 0;
>  }
> Index: linux-2.6.31-rc7-mmotm-090827-1651/include/linux/node.h
> ===================================================================
> --- linux-2.6.31-rc7-mmotm-090827-1651.orig/include/linux/node.h	2009-09-09 11:57:26.000000000 -0400
> +++ linux-2.6.31-rc7-mmotm-090827-1651/include/linux/node.h	2009-09-09 11:57:37.000000000 -0400
> @@ -28,6 +28,7 @@ struct node {
>  
>  struct memory_block;
>  extern struct node node_devices[];
> +typedef  void (*NODE_REGISTRATION_FUNC)(struct node *);
>  
>  extern int register_node(struct node *, int, struct node *);
>  extern void unregister_node(struct node *node);
> @@ -39,6 +40,8 @@ extern int unregister_cpu_under_node(uns
>  extern int register_mem_sect_under_node(struct memory_block *mem_blk,
>  						int nid);
>  extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk);
> +extern void register_hugetlbfs_with_node(NODE_REGISTRATION_FUNC doregister,
> +					 NODE_REGISTRATION_FUNC unregister);
>  #else
>  static inline int register_one_node(int nid)
>  {
> @@ -65,6 +68,11 @@ static inline int unregister_mem_sect_un
>  {
>  	return 0;
>  }
> +
> +static inline void register_hugetlbfs_with_node(NODE_REGISTRATION_FUNC reg,
> +						NODE_REGISTRATION_FUNC unreg)
> +{
> +}
>  #endif
>  
>  #define to_node(sys_device) container_of(sys_device, struct node, sysdev)
> 

-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab