[PATCH 7/12] hugetlb: register per node hugepages attributes
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@xxxxxx>
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Reviewed-by: Andi Kleen <andi@xxxxxxxxxxxxxx>
---
Against: 2.6.31-mmotm-090925-1435
V2: remove dependency on kobject private bitfield. Search
global hstates then all per node hstates for kobject
match in attribute show/store functions.
V3: rebase atop the mempolicy-based hugepage alloc/free;
use custom "nodes_allowed" to restrict alloc/free to
a specific node via per node attributes. Per node
attribute overrides mempolicy. I.e., mempolicy only
applies to global attributes.
V5: Fix issues raised by Mel Gorman:
+ add !NUMA versions of hugetlb_[un]register_node()
+ rename 'hi' to 'i' in kobj_to_node_hstate()
+ rename (count, input) to (len, count) in nr_hugepages_store()
+ moved per node hugepages_kobj and hstate_kobjs[] from the
struct node [sysdev] to hugetlb.c private arrays.
+ changed registration mechanism so that hugetlbfs [a module]
register its attributes registration callbacks with the node
driver, eliminating the dependency between the node driver
and hugetlbfs. From it's init func, hugetlbfs will register
all on-line nodes' hugepage sysfs attributes along with
hugetlbfs' attributes register/unregister functions. The
node driver will use these functions to [un]register nodes
with hugetlbfs on node hot-plug.
+ replaced hugetlb.c private "nodes_allowed_from_node()" with
[new] generic "alloc_nodemask_of_node()".
V5a: + fix !NUMA register_hugetlbfs_with_node(): don't use
keyword 'do' as parameter name!
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()
V7: + add ifdefs + stubs to eliminate unneeded hugetlb registration
functions when HUGETLBFS not configured.
+ add some comments to per node hstate registration code in
hugetlb.c
V8: + folded in subsequent patch to reorganize sysctl and sysfs
attribute handlers to pass nodes_allowed mask t0
set_max_huge_pages()
V9: + fix rejects caused by new patch 5/11 -- NODEMASK_ALLOC() rework.
V10: + handle NODEMASK_ALLOC kmalloc failure in '_store_common'
drivers/base/node.c | 39 +++++++
include/linux/node.h | 11 ++
mm/hugetlb.c | 274 ++++++++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 298 insertions(+), 26 deletions(-)
Index: linux-2.6.31-mmotm-090925-1435/drivers/base/node.c
===================================================================
--- linux-2.6.31-mmotm-090925-1435.orig/drivers/base/node.c 2009-10-07 12:31:51.000000000 -0400
+++ linux-2.6.31-mmotm-090925-1435/drivers/base/node.c 2009-10-07 12:32:01.000000000 -0400
@@ -173,6 +173,43 @@ static ssize_t node_read_distance(struct
}
static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
+#ifdef CONFIG_HUGETLBFS
+/*
+ * hugetlbfs per node attributes registration interface:
+ * When/if hugetlb[fs] subsystem initializes [sometime after this module],
+ * it will register its per node attributes for all nodes online at that
+ * time. It will also call register_hugetlbfs_with_node(), below, to
+ * register its 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.
+ */
+static node_registration_func_t __hugetlb_register_node;
+static node_registration_func_t __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_t doregister,
+ node_registration_func_t unregister)
+{
+ __hugetlb_register_node = doregister;
+ __hugetlb_unregister_node = unregister;
+}
+#else
+static inline void hugetlb_register_node(struct node *node) {}
+
+static inline void hugetlb_unregister_node(struct node *node) {}
+#endif
+
/*
* register_node - Setup a sysfs device for a node.
@@ -196,6 +233,7 @@ 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;
}
@@ -216,6 +254,7 @@ 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-mmotm-090925-1435/mm/hugetlb.c
===================================================================
--- linux-2.6.31-mmotm-090925-1435.orig/mm/hugetlb.c 2009-10-07 12:31:59.000000000 -0400
+++ linux-2.6.31-mmotm-090925-1435/mm/hugetlb.c 2009-10-07 12:32:01.000000000 -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;
@@ -1320,39 +1321,71 @@ 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_common(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_common(bool obey_mempolicy,
struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t len)
{
int err;
+ int nid;
unsigned long count;
- struct hstate *h = kobj_to_hstate(kobj);
+ struct hstate *h;
NODEMASK_ALLOC(nodemask_t, nodes_allowed);
err = strict_strtoul(buf, 10, &count);
if (err)
return 0;
- if (!(obey_mempolicy && init_nodemask_of_mempolicy(nodes_allowed))) {
- NODEMASK_FREE(nodes_allowed);
- nodes_allowed = &node_online_map;
- }
+ h = kobj_to_hstate(kobj, &nid);
+ if (nid == NUMA_NO_NODE) {
+ /*
+ * global hstate attribute
+ */
+ if (!(obey_mempolicy &&
+ init_nodemask_of_mempolicy(nodes_allowed))) {
+ NODEMASK_FREE(nodes_allowed);
+ nodes_allowed = &node_states[N_HIGH_MEMORY];
+ }
+ } else if (nodes_allowed) {
+ /*
+ * per node hstate attribute: adjust count to global,
+ * but restrict alloc/free to the specified node.
+ */
+ count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
+ init_nodemask_of_node(nodes_allowed, nid);
+ } else
+ nodes_allowed = &node_states[N_HIGH_MEMORY];
+
h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
if (nodes_allowed != &node_online_map)
@@ -1398,7 +1431,7 @@ HSTATE_ATTR(nr_hugepages_mempolicy);
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,
@@ -1406,7 +1439,7 @@ static ssize_t nr_overcommit_hugepages_s
{
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)
@@ -1423,15 +1456,24 @@ 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);
@@ -1439,8 +1481,17 @@ 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);
@@ -1460,19 +1511,21 @@ 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;
}
@@ -1487,17 +1540,184 @@ 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
+
+/*
+ * node_hstate/s - associate per node hstate attributes, via their kobjects,
+ * with node sysdevs in node_devices[] using a parallel array. The array
+ * index of a node sysdev or _hstate == node id.
+ * This is here to avoid any static dependency of the node sysdev driver, in
+ * the base kernel, on the hugetlb module.
+ */
+struct node_hstate {
+ struct kobject *hugepages_kobj;
+ struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
+};
+struct node_hstate node_hstates[MAX_NUMNODES];
+
+/*
+ * A subset of global hstate attributes for node sysdevs
+ */
+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,
+};
+
+/*
+ * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj.
+ * Returns node id via non-NULL nidp.
+ */
+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;
+}
+
+/*
+ * Unregister hstate attributes from a single node sysdev.
+ * No-op if no hstate attributes attached.
+ */
+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;
+}
+
+/*
+ * hugetlb module exit: unregister hstate attributes from node sysdevs
+ * that have them.
+ */
+static void hugetlb_unregister_all_nodes(void)
+{
+ int nid;
+
+ /*
+ * disable node sysdev registrations.
+ */
+ register_hugetlbfs_with_node(NULL, NULL);
+
+ /*
+ * remove hstate attributes from any nodes that have them.
+ */
+ for (nid = 0; nid < nr_node_ids; nid++)
+ hugetlb_unregister_node(&node_devices[nid]);
+}
+
+/*
+ * Register hstate attributes for a single node sysdev.
+ * No-op if attributes already registered.
+ */
+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;
+ }
+ }
+}
+
+/*
+ * hugetlb init time: register hstate attributes for all registered
+ * node sysdevs. All on-line nodes should have registered their
+ * associated sysdev by the time the hugetlb module initializes.
+ */
+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);
+ }
+
+ /*
+ * Let the node sysdev driver know we're here so it can
+ * [un]register hstate attributes on node hotplug.
+ */
+ 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]);
}
@@ -1532,6 +1752,8 @@ static int __init hugetlb_init(void)
hugetlb_sysfs_init();
+ hugetlb_register_all_nodes();
+
return 0;
}
module_init(hugetlb_init);
Index: linux-2.6.31-mmotm-090925-1435/include/linux/node.h
===================================================================
--- linux-2.6.31-mmotm-090925-1435.orig/include/linux/node.h 2009-10-07 12:31:51.000000000 -0400
+++ linux-2.6.31-mmotm-090925-1435/include/linux/node.h 2009-10-07 12:32:01.000000000 -0400
@@ -28,6 +28,7 @@ struct node {
struct memory_block;
extern struct node node_devices[];
+typedef void (*node_registration_func_t)(struct node *);
extern int register_node(struct node *, int, struct node *);
extern void unregister_node(struct node *node);
@@ -39,6 +40,11 @@ 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);
+
+#ifdef CONFIG_HUGETLBFS
+extern void register_hugetlbfs_with_node(node_registration_func_t doregister,
+ node_registration_func_t unregister);
+#endif
#else
static inline int register_one_node(int nid)
{
@@ -65,6 +71,11 @@ static inline int unregister_mem_sect_un
{
return 0;
}
+
+static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
+ node_registration_func_t unreg)
+{
+}
#endif
#define to_node(sys_device) container_of(sys_device, struct node, sysdev)
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