linux-stable/drivers/base/node.c
Shakeel Butt b603894248 mm: memcg: add swapcache stat for memcg v2
This patch adds swapcache stat for the cgroup v2.  The swapcache
represents the memory that is accounted against both the memory and the
swap limit of the cgroup.  The main motivation behind exposing the
swapcache stat is for enabling users to gracefully migrate from cgroup
v1's memsw counter to cgroup v2's memory and swap counters.

Cgroup v1's memsw limit allows users to limit the memory+swap usage of a
workload but without control on the exact proportion of memory and swap.
Cgroup v2 provides separate limits for memory and swap which enables more
control on the exact usage of memory and swap individually for the
workload.

With some little subtleties, the v1's memsw limit can be switched with the
sum of the v2's memory and swap limits.  However the alternative for memsw
usage is not yet available in cgroup v2.  Exposing per-cgroup swapcache
stat enables that alternative.  Adding the memory usage and swap usage and
subtracting the swapcache will approximate the memsw usage.  This will
help in the transparent migration of the workloads depending on memsw
usage and limit to v2' memory and swap counters.

The reasons these applications are still interested in this approximate
memsw usage are: (1) these applications are not really interested in two
separate memory and swap usage metrics.  A single usage metric is more
simple to use and reason about for them.

(2) The memsw usage metric hides the underlying system's swap setup from
the applications.  Applications with multiple instances running in a
datacenter with heterogeneous systems (some have swap and some don't) will
keep seeing a consistent view of their usage.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]

Link: https://lkml.kernel.org/r/20210108155813.2914586-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00

1073 lines
28 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Basic Node interface support
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
#include <linux/vmstat.h>
#include <linux/notifier.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/compaction.h>
#include <linux/cpumask.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/swap.h>
#include <linux/slab.h>
static struct bus_type node_subsys = {
.name = "node",
.dev_name = "node",
};
static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
{
ssize_t n;
cpumask_var_t mask;
struct node *node_dev = to_node(dev);
/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
n = cpumap_print_to_pagebuf(list, buf, mask);
free_cpumask_var(mask);
return n;
}
static inline ssize_t cpumap_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return node_read_cpumap(dev, false, buf);
}
static DEVICE_ATTR_RO(cpumap);
static inline ssize_t cpulist_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return node_read_cpumap(dev, true, buf);
}
static DEVICE_ATTR_RO(cpulist);
/**
* struct node_access_nodes - Access class device to hold user visible
* relationships to other nodes.
* @dev: Device for this memory access class
* @list_node: List element in the node's access list
* @access: The access class rank
* @hmem_attrs: Heterogeneous memory performance attributes
*/
struct node_access_nodes {
struct device dev;
struct list_head list_node;
unsigned access;
#ifdef CONFIG_HMEM_REPORTING
struct node_hmem_attrs hmem_attrs;
#endif
};
#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
static struct attribute *node_init_access_node_attrs[] = {
NULL,
};
static struct attribute *node_targ_access_node_attrs[] = {
NULL,
};
static const struct attribute_group initiators = {
.name = "initiators",
.attrs = node_init_access_node_attrs,
};
static const struct attribute_group targets = {
.name = "targets",
.attrs = node_targ_access_node_attrs,
};
static const struct attribute_group *node_access_node_groups[] = {
&initiators,
&targets,
NULL,
};
static void node_remove_accesses(struct node *node)
{
struct node_access_nodes *c, *cnext;
list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
list_del(&c->list_node);
device_unregister(&c->dev);
}
}
static void node_access_release(struct device *dev)
{
kfree(to_access_nodes(dev));
}
static struct node_access_nodes *node_init_node_access(struct node *node,
unsigned access)
{
struct node_access_nodes *access_node;
struct device *dev;
list_for_each_entry(access_node, &node->access_list, list_node)
if (access_node->access == access)
return access_node;
access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
if (!access_node)
return NULL;
access_node->access = access;
dev = &access_node->dev;
dev->parent = &node->dev;
dev->release = node_access_release;
dev->groups = node_access_node_groups;
if (dev_set_name(dev, "access%u", access))
goto free;
if (device_register(dev))
goto free_name;
pm_runtime_no_callbacks(dev);
list_add_tail(&access_node->list_node, &node->access_list);
return access_node;
free_name:
kfree_const(dev->kobj.name);
free:
kfree(access_node);
return NULL;
}
#ifdef CONFIG_HMEM_REPORTING
#define ACCESS_ATTR(name) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sysfs_emit(buf, "%u\n", \
to_access_nodes(dev)->hmem_attrs.name); \
} \
static DEVICE_ATTR_RO(name)
ACCESS_ATTR(read_bandwidth);
ACCESS_ATTR(read_latency);
ACCESS_ATTR(write_bandwidth);
ACCESS_ATTR(write_latency);
static struct attribute *access_attrs[] = {
&dev_attr_read_bandwidth.attr,
&dev_attr_read_latency.attr,
&dev_attr_write_bandwidth.attr,
&dev_attr_write_latency.attr,
NULL,
};
/**
* node_set_perf_attrs - Set the performance values for given access class
* @nid: Node identifier to be set
* @hmem_attrs: Heterogeneous memory performance attributes
* @access: The access class the for the given attributes
*/
void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
unsigned access)
{
struct node_access_nodes *c;
struct node *node;
int i;
if (WARN_ON_ONCE(!node_online(nid)))
return;
node = node_devices[nid];
c = node_init_node_access(node, access);
if (!c)
return;
c->hmem_attrs = *hmem_attrs;
for (i = 0; access_attrs[i] != NULL; i++) {
if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
"initiators")) {
pr_info("failed to add performance attribute to node %d\n",
nid);
break;
}
}
}
/**
* struct node_cache_info - Internal tracking for memory node caches
* @dev: Device represeting the cache level
* @node: List element for tracking in the node
* @cache_attrs:Attributes for this cache level
*/
struct node_cache_info {
struct device dev;
struct list_head node;
struct node_cache_attrs cache_attrs;
};
#define to_cache_info(device) container_of(device, struct node_cache_info, dev)
#define CACHE_ATTR(name, fmt) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sysfs_emit(buf, fmt "\n", \
to_cache_info(dev)->cache_attrs.name); \
} \
DEVICE_ATTR_RO(name);
CACHE_ATTR(size, "%llu")
CACHE_ATTR(line_size, "%u")
CACHE_ATTR(indexing, "%u")
CACHE_ATTR(write_policy, "%u")
static struct attribute *cache_attrs[] = {
&dev_attr_indexing.attr,
&dev_attr_size.attr,
&dev_attr_line_size.attr,
&dev_attr_write_policy.attr,
NULL,
};
ATTRIBUTE_GROUPS(cache);
static void node_cache_release(struct device *dev)
{
kfree(dev);
}
static void node_cacheinfo_release(struct device *dev)
{
struct node_cache_info *info = to_cache_info(dev);
kfree(info);
}
static void node_init_cache_dev(struct node *node)
{
struct device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return;
dev->parent = &node->dev;
dev->release = node_cache_release;
if (dev_set_name(dev, "memory_side_cache"))
goto free_dev;
if (device_register(dev))
goto free_name;
pm_runtime_no_callbacks(dev);
node->cache_dev = dev;
return;
free_name:
kfree_const(dev->kobj.name);
free_dev:
kfree(dev);
}
/**
* node_add_cache() - add cache attribute to a memory node
* @nid: Node identifier that has new cache attributes
* @cache_attrs: Attributes for the cache being added
*/
void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
{
struct node_cache_info *info;
struct device *dev;
struct node *node;
if (!node_online(nid) || !node_devices[nid])
return;
node = node_devices[nid];
list_for_each_entry(info, &node->cache_attrs, node) {
if (info->cache_attrs.level == cache_attrs->level) {
dev_warn(&node->dev,
"attempt to add duplicate cache level:%d\n",
cache_attrs->level);
return;
}
}
if (!node->cache_dev)
node_init_cache_dev(node);
if (!node->cache_dev)
return;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return;
dev = &info->dev;
dev->parent = node->cache_dev;
dev->release = node_cacheinfo_release;
dev->groups = cache_groups;
if (dev_set_name(dev, "index%d", cache_attrs->level))
goto free_cache;
info->cache_attrs = *cache_attrs;
if (device_register(dev)) {
dev_warn(&node->dev, "failed to add cache level:%d\n",
cache_attrs->level);
goto free_name;
}
pm_runtime_no_callbacks(dev);
list_add_tail(&info->node, &node->cache_attrs);
return;
free_name:
kfree_const(dev->kobj.name);
free_cache:
kfree(info);
}
static void node_remove_caches(struct node *node)
{
struct node_cache_info *info, *next;
if (!node->cache_dev)
return;
list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
list_del(&info->node);
device_unregister(&info->dev);
}
device_unregister(node->cache_dev);
}
static void node_init_caches(unsigned int nid)
{
INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
}
#else
static void node_init_caches(unsigned int nid) { }
static void node_remove_caches(struct node *node) { }
#endif
#define K(x) ((x) << (PAGE_SHIFT - 10))
static ssize_t node_read_meminfo(struct device *dev,
struct device_attribute *attr, char *buf)
{
int len = 0;
int nid = dev->id;
struct pglist_data *pgdat = NODE_DATA(nid);
struct sysinfo i;
unsigned long sreclaimable, sunreclaimable;
unsigned long swapcached = 0;
si_meminfo_node(&i, nid);
sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
#ifdef CONFIG_SWAP
swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
#endif
len = sysfs_emit_at(buf, len,
"Node %d MemTotal: %8lu kB\n"
"Node %d MemFree: %8lu kB\n"
"Node %d MemUsed: %8lu kB\n"
"Node %d SwapCached: %8lu kB\n"
"Node %d Active: %8lu kB\n"
"Node %d Inactive: %8lu kB\n"
"Node %d Active(anon): %8lu kB\n"
"Node %d Inactive(anon): %8lu kB\n"
"Node %d Active(file): %8lu kB\n"
"Node %d Inactive(file): %8lu kB\n"
"Node %d Unevictable: %8lu kB\n"
"Node %d Mlocked: %8lu kB\n",
nid, K(i.totalram),
nid, K(i.freeram),
nid, K(i.totalram - i.freeram),
nid, K(swapcached),
nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
node_page_state(pgdat, NR_ACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
node_page_state(pgdat, NR_INACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
#ifdef CONFIG_HIGHMEM
len += sysfs_emit_at(buf, len,
"Node %d HighTotal: %8lu kB\n"
"Node %d HighFree: %8lu kB\n"
"Node %d LowTotal: %8lu kB\n"
"Node %d LowFree: %8lu kB\n",
nid, K(i.totalhigh),
nid, K(i.freehigh),
nid, K(i.totalram - i.totalhigh),
nid, K(i.freeram - i.freehigh));
#endif
len += sysfs_emit_at(buf, len,
"Node %d Dirty: %8lu kB\n"
"Node %d Writeback: %8lu kB\n"
"Node %d FilePages: %8lu kB\n"
"Node %d Mapped: %8lu kB\n"
"Node %d AnonPages: %8lu kB\n"
"Node %d Shmem: %8lu kB\n"
"Node %d KernelStack: %8lu kB\n"
#ifdef CONFIG_SHADOW_CALL_STACK
"Node %d ShadowCallStack:%8lu kB\n"
#endif
"Node %d PageTables: %8lu kB\n"
"Node %d NFS_Unstable: %8lu kB\n"
"Node %d Bounce: %8lu kB\n"
"Node %d WritebackTmp: %8lu kB\n"
"Node %d KReclaimable: %8lu kB\n"
"Node %d Slab: %8lu kB\n"
"Node %d SReclaimable: %8lu kB\n"
"Node %d SUnreclaim: %8lu kB\n"
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
"Node %d AnonHugePages: %8lu kB\n"
"Node %d ShmemHugePages: %8lu kB\n"
"Node %d ShmemPmdMapped: %8lu kB\n"
"Node %d FileHugePages: %8lu kB\n"
"Node %d FilePmdMapped: %8lu kB\n"
#endif
,
nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
nid, K(node_page_state(pgdat, NR_WRITEBACK)),
nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
nid, K(i.sharedram),
nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
#ifdef CONFIG_SHADOW_CALL_STACK
nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
#endif
nid, K(node_page_state(pgdat, NR_PAGETABLE)),
nid, 0UL,
nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
nid, K(sreclaimable +
node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
nid, K(sreclaimable + sunreclaimable),
nid, K(sreclaimable),
nid, K(sunreclaimable)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
,
nid, K(node_page_state(pgdat, NR_ANON_THPS)),
nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
nid, K(node_page_state(pgdat, NR_FILE_THPS)),
nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
#endif
);
len += hugetlb_report_node_meminfo(buf, len, nid);
return len;
}
#undef K
static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
static ssize_t node_read_numastat(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf,
"numa_hit %lu\n"
"numa_miss %lu\n"
"numa_foreign %lu\n"
"interleave_hit %lu\n"
"local_node %lu\n"
"other_node %lu\n",
sum_zone_numa_state(dev->id, NUMA_HIT),
sum_zone_numa_state(dev->id, NUMA_MISS),
sum_zone_numa_state(dev->id, NUMA_FOREIGN),
sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
sum_zone_numa_state(dev->id, NUMA_LOCAL),
sum_zone_numa_state(dev->id, NUMA_OTHER));
}
static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
static ssize_t node_read_vmstat(struct device *dev,
struct device_attribute *attr, char *buf)
{
int nid = dev->id;
struct pglist_data *pgdat = NODE_DATA(nid);
int i;
int len = 0;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
len += sysfs_emit_at(buf, len, "%s %lu\n",
zone_stat_name(i),
sum_zone_node_page_state(nid, i));
#ifdef CONFIG_NUMA
for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
len += sysfs_emit_at(buf, len, "%s %lu\n",
numa_stat_name(i),
sum_zone_numa_state(nid, i));
#endif
for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
unsigned long pages = node_page_state_pages(pgdat, i);
if (vmstat_item_print_in_thp(i))
pages /= HPAGE_PMD_NR;
len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
pages);
}
return len;
}
static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
static ssize_t node_read_distance(struct device *dev,
struct device_attribute *attr, char *buf)
{
int nid = dev->id;
int len = 0;
int i;
/*
* buf is currently PAGE_SIZE in length and each node needs 4 chars
* at the most (distance + space or newline).
*/
BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
for_each_online_node(i) {
len += sysfs_emit_at(buf, len, "%s%d",
i ? " " : "", node_distance(nid, i));
}
len += sysfs_emit_at(buf, len, "\n");
return len;
}
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
static struct attribute *node_dev_attrs[] = {
&dev_attr_cpumap.attr,
&dev_attr_cpulist.attr,
&dev_attr_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
NULL
};
ATTRIBUTE_GROUPS(node_dev);
#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 online nodes with
* memory. 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 bool hugetlb_register_node(struct node *node)
{
if (__hugetlb_register_node &&
node_state(node->dev.id, N_MEMORY)) {
__hugetlb_register_node(node);
return true;
}
return false;
}
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
static void node_device_release(struct device *dev)
{
struct node *node = to_node(dev);
#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
/*
* We schedule the work only when a memory section is
* onlined/offlined on this node. When we come here,
* all the memory on this node has been offlined,
* so we won't enqueue new work to this work.
*
* The work is using node->node_work, so we should
* flush work before freeing the memory.
*/
flush_work(&node->node_work);
#endif
kfree(node);
}
/*
* register_node - Setup a sysfs device for a node.
* @num - Node number to use when creating the device.
*
* Initialize and register the node device.
*/
static int register_node(struct node *node, int num)
{
int error;
node->dev.id = num;
node->dev.bus = &node_subsys;
node->dev.release = node_device_release;
node->dev.groups = node_dev_groups;
error = device_register(&node->dev);
if (error)
put_device(&node->dev);
else {
hugetlb_register_node(node);
compaction_register_node(node);
}
return error;
}
/**
* unregister_node - unregister a node device
* @node: node going away
*
* Unregisters a node device @node. All the devices on the node must be
* unregistered before calling this function.
*/
void unregister_node(struct node *node)
{
hugetlb_unregister_node(node); /* no-op, if memoryless node */
node_remove_accesses(node);
node_remove_caches(node);
device_unregister(&node->dev);
}
struct node *node_devices[MAX_NUMNODES];
/*
* register cpu under node
*/
int register_cpu_under_node(unsigned int cpu, unsigned int nid)
{
int ret;
struct device *obj;
if (!node_online(nid))
return 0;
obj = get_cpu_device(cpu);
if (!obj)
return 0;
ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
&obj->kobj,
kobject_name(&obj->kobj));
if (ret)
return ret;
return sysfs_create_link(&obj->kobj,
&node_devices[nid]->dev.kobj,
kobject_name(&node_devices[nid]->dev.kobj));
}
/**
* register_memory_node_under_compute_node - link memory node to its compute
* node for a given access class.
* @mem_nid: Memory node number
* @cpu_nid: Cpu node number
* @access: Access class to register
*
* Description:
* For use with platforms that may have separate memory and compute nodes.
* This function will export node relationships linking which memory
* initiator nodes can access memory targets at a given ranked access
* class.
*/
int register_memory_node_under_compute_node(unsigned int mem_nid,
unsigned int cpu_nid,
unsigned access)
{
struct node *init_node, *targ_node;
struct node_access_nodes *initiator, *target;
int ret;
if (!node_online(cpu_nid) || !node_online(mem_nid))
return -ENODEV;
init_node = node_devices[cpu_nid];
targ_node = node_devices[mem_nid];
initiator = node_init_node_access(init_node, access);
target = node_init_node_access(targ_node, access);
if (!initiator || !target)
return -ENOMEM;
ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
&targ_node->dev.kobj,
dev_name(&targ_node->dev));
if (ret)
return ret;
ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
&init_node->dev.kobj,
dev_name(&init_node->dev));
if (ret)
goto err;
return 0;
err:
sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
dev_name(&targ_node->dev));
return ret;
}
int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
{
struct device *obj;
if (!node_online(nid))
return 0;
obj = get_cpu_device(cpu);
if (!obj)
return 0;
sysfs_remove_link(&node_devices[nid]->dev.kobj,
kobject_name(&obj->kobj));
sysfs_remove_link(&obj->kobj,
kobject_name(&node_devices[nid]->dev.kobj));
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
static int __ref get_nid_for_pfn(unsigned long pfn)
{
if (!pfn_valid_within(pfn))
return -1;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
if (system_state < SYSTEM_RUNNING)
return early_pfn_to_nid(pfn);
#endif
return pfn_to_nid(pfn);
}
static void do_register_memory_block_under_node(int nid,
struct memory_block *mem_blk)
{
int ret;
/*
* If this memory block spans multiple nodes, we only indicate
* the last processed node.
*/
mem_blk->nid = nid;
ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
&mem_blk->dev.kobj,
kobject_name(&mem_blk->dev.kobj));
if (ret && ret != -EEXIST)
dev_err_ratelimited(&node_devices[nid]->dev,
"can't create link to %s in sysfs (%d)\n",
kobject_name(&mem_blk->dev.kobj), ret);
ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
&node_devices[nid]->dev.kobj,
kobject_name(&node_devices[nid]->dev.kobj));
if (ret && ret != -EEXIST)
dev_err_ratelimited(&mem_blk->dev,
"can't create link to %s in sysfs (%d)\n",
kobject_name(&node_devices[nid]->dev.kobj),
ret);
}
/* register memory section under specified node if it spans that node */
static int register_mem_block_under_node_early(struct memory_block *mem_blk,
void *arg)
{
unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
int nid = *(int *)arg;
unsigned long pfn;
for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
int page_nid;
/*
* memory block could have several absent sections from start.
* skip pfn range from absent section
*/
if (!pfn_in_present_section(pfn)) {
pfn = round_down(pfn + PAGES_PER_SECTION,
PAGES_PER_SECTION) - 1;
continue;
}
/*
* We need to check if page belongs to nid only at the boot
* case because node's ranges can be interleaved.
*/
page_nid = get_nid_for_pfn(pfn);
if (page_nid < 0)
continue;
if (page_nid != nid)
continue;
do_register_memory_block_under_node(nid, mem_blk);
return 0;
}
/* mem section does not span the specified node */
return 0;
}
/*
* During hotplug we know that all pages in the memory block belong to the same
* node.
*/
static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
void *arg)
{
int nid = *(int *)arg;
do_register_memory_block_under_node(nid, mem_blk);
return 0;
}
/*
* Unregister a memory block device under the node it spans. Memory blocks
* with multiple nodes cannot be offlined and therefore also never be removed.
*/
void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
{
if (mem_blk->nid == NUMA_NO_NODE)
return;
sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
kobject_name(&mem_blk->dev.kobj));
sysfs_remove_link(&mem_blk->dev.kobj,
kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
}
void link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn,
enum meminit_context context)
{
walk_memory_blocks_func_t func;
if (context == MEMINIT_HOTPLUG)
func = register_mem_block_under_node_hotplug;
else
func = register_mem_block_under_node_early;
walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
(void *)&nid, func);
return;
}
#ifdef CONFIG_HUGETLBFS
/*
* Handle per node hstate attribute [un]registration on transistions
* to/from memoryless state.
*/
static void node_hugetlb_work(struct work_struct *work)
{
struct node *node = container_of(work, struct node, node_work);
/*
* We only get here when a node transitions to/from memoryless state.
* We can detect which transition occurred by examining whether the
* node has memory now. hugetlb_register_node() already check this
* so we try to register the attributes. If that fails, then the
* node has transitioned to memoryless, try to unregister the
* attributes.
*/
if (!hugetlb_register_node(node))
hugetlb_unregister_node(node);
}
static void init_node_hugetlb_work(int nid)
{
INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
}
static int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
struct memory_notify *mnb = arg;
int nid = mnb->status_change_nid;
switch (action) {
case MEM_ONLINE:
case MEM_OFFLINE:
/*
* offload per node hstate [un]registration to a work thread
* when transitioning to/from memoryless state.
*/
if (nid != NUMA_NO_NODE)
schedule_work(&node_devices[nid]->node_work);
break;
case MEM_GOING_ONLINE:
case MEM_GOING_OFFLINE:
case MEM_CANCEL_ONLINE:
case MEM_CANCEL_OFFLINE:
default:
break;
}
return NOTIFY_OK;
}
#endif /* CONFIG_HUGETLBFS */
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
#if !defined(CONFIG_MEMORY_HOTPLUG_SPARSE) || \
!defined(CONFIG_HUGETLBFS)
static inline int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
return NOTIFY_OK;
}
static void init_node_hugetlb_work(int nid) { }
#endif
int __register_one_node(int nid)
{
int error;
int cpu;
node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
if (!node_devices[nid])
return -ENOMEM;
error = register_node(node_devices[nid], nid);
/* link cpu under this node */
for_each_present_cpu(cpu) {
if (cpu_to_node(cpu) == nid)
register_cpu_under_node(cpu, nid);
}
INIT_LIST_HEAD(&node_devices[nid]->access_list);
/* initialize work queue for memory hot plug */
init_node_hugetlb_work(nid);
node_init_caches(nid);
return error;
}
void unregister_one_node(int nid)
{
if (!node_devices[nid])
return;
unregister_node(node_devices[nid]);
node_devices[nid] = NULL;
}
/*
* node states attributes
*/
struct node_attr {
struct device_attribute attr;
enum node_states state;
};
static ssize_t show_node_state(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct node_attr *na = container_of(attr, struct node_attr, attr);
return sysfs_emit(buf, "%*pbl\n",
nodemask_pr_args(&node_states[na->state]));
}
#define _NODE_ATTR(name, state) \
{ __ATTR(name, 0444, show_node_state, NULL), state }
static struct node_attr node_state_attr[] = {
[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
#endif
[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
N_GENERIC_INITIATOR),
};
static struct attribute *node_state_attrs[] = {
&node_state_attr[N_POSSIBLE].attr.attr,
&node_state_attr[N_ONLINE].attr.attr,
&node_state_attr[N_NORMAL_MEMORY].attr.attr,
#ifdef CONFIG_HIGHMEM
&node_state_attr[N_HIGH_MEMORY].attr.attr,
#endif
&node_state_attr[N_MEMORY].attr.attr,
&node_state_attr[N_CPU].attr.attr,
&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
NULL
};
static struct attribute_group memory_root_attr_group = {
.attrs = node_state_attrs,
};
static const struct attribute_group *cpu_root_attr_groups[] = {
&memory_root_attr_group,
NULL,
};
#define NODE_CALLBACK_PRI 2 /* lower than SLAB */
static int __init register_node_type(void)
{
int ret;
BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
if (!ret) {
static struct notifier_block node_memory_callback_nb = {
.notifier_call = node_memory_callback,
.priority = NODE_CALLBACK_PRI,
};
register_hotmemory_notifier(&node_memory_callback_nb);
}
/*
* Note: we're not going to unregister the node class if we fail
* to register the node state class attribute files.
*/
return ret;
}
postcore_initcall(register_node_type);