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linux-stable/drivers/base/node.c
Jiaqi Yan 44b8f8bf24 mm: memory-failure: add memory failure stats to sysfs 
Patch series "Introduce per NUMA node memory error statistics", v2.

Background
==========

In the RFC for Kernel Support of Memory Error Detection [1], one advantage
of software-based scanning over hardware patrol scrubber is the ability to
make statistics visible to system administrators.  The statistics include
2 categories:

* Memory error statistics, for example, how many memory error are
  encountered, how many of them are recovered by the kernel.  Note these
  memory errors are non-fatal to kernel: during the machine check
  exception (MCE) handling kernel already classified MCE's severity to be
  unnecessary to panic (but either action required or optional).

* Scanner statistics, for example how many times the scanner have fully
  scanned a NUMA node, how many errors are first detected by the scanner.

The memory error statistics are useful to userspace and actually not
specific to scanner detected memory errors, and are the focus of this
patchset.

Motivation
==========

Memory error stats are important to userspace but insufficient in kernel
today.  Datacenter administrators can better monitor a machine's memory
health with the visible stats.  For example, while memory errors are
inevitable on servers with 10+ TB memory, starting server maintenance when
there are only 1~2 recovered memory errors could be overreacting; in cloud
production environment maintenance usually means live migrate all the
workload running on the server and this usually causes nontrivial
disruption to the customer.  Providing insight into the scope of memory
errors on a system helps to determine the appropriate follow-up action. 
In addition, the kernel's existing memory error stats need to be
standardized so that userspace can reliably count on their usefulness.

Today kernel provides following memory error info to userspace, but they
are not sufficient or have disadvantages:
* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
  not per NUMA node stats though
* ras:memory_failure_event: only available after explicitly enabled
* /dev/mcelog provides many useful info about the MCEs, but doesn't
  capture how memory_failure recovered memory MCEs
* kernel logs: userspace needs to process log text

Exposing memory error stats is also a good start for the in-kernel memory
error detector.  Today the data source of memory error stats are either
direct memory error consumption, or hardware patrol scrubber detection
(either signaled as UCNA or SRAO).  Once in-kernel memory scanner is
implemented, it will be the main source as it is usually configured to
scan memory DIMMs constantly and faster than hardware patrol scrubber.

How Implemented
===============

As Naoya pointed out [2], exposing memory error statistics to userspace is
useful independent of software or hardware scanner.  Therefore we
implement the memory error statistics independent of the in-kernel memory
error detector.  It exposes the following per NUMA node memory error
counters:

  /sys/devices/system/node/node${X}/memory_failure/total
  /sys/devices/system/node/node${X}/memory_failure/recovered
  /sys/devices/system/node/node${X}/memory_failure/ignored
  /sys/devices/system/node/node${X}/memory_failure/failed
  /sys/devices/system/node/node${X}/memory_failure/delayed

These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively.  This approach can be
easier to extend for future use cases than /proc/meminfo, trace event, and
log.  The following math holds for the statistics:

* total = recovered + ignored + failed + delayed

These memory error stats are reset during machine boot.

The 1st commit introduces these sysfs entries.  The 2nd commit populates
memory error stats every time memory_failure attempts memory error
recovery.  The 3rd commit adds documentations for introduced stats.

[1] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#mc22959244f5388891c523882e61163c6e4d703af
[2] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#m52d8d7a333d8536bd7ce74253298858b1c0c0ac6


This patch (of 3):

Today kernel provides following memory error info to userspace, but each
has its own disadvantage

* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
  not per NUMA node stats though

* ras:memory_failure_event: only available after explicitly enabled

* /dev/mcelog provides many useful info about the MCEs, but
  doesn't capture how memory_failure recovered memory MCEs

* kernel logs: userspace needs to process log text

Exposes per NUMA node memory error stats as sysfs entries:

  /sys/devices/system/node/node${X}/memory_failure/total
  /sys/devices/system/node/node${X}/memory_failure/recovered
  /sys/devices/system/node/node${X}/memory_failure/ignored
  /sys/devices/system/node/node${X}/memory_failure/failed
  /sys/devices/system/node/node${X}/memory_failure/delayed

These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively.  The following math
holds for the statistics:

* total = recovered + ignored + failed + delayed

Link: https://lkml.kernel.org/r/20230120034622.2698268-1-jiaqiyan@google.com
Link: https://lkml.kernel.org/r/20230120034622.2698268-2-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:28 -08:00

969 lines
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// 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>
#include <linux/hugetlb.h>
static struct bus_type node_subsys = {
.name = "node",
.dev_name = "node",
};
static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
cpumask_var_t mask;
ssize_t n;
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_bitmask_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES);
static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
cpumask_var_t mask;
ssize_t n;
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_list_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES);
/**
* 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 int 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 int 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 int 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); \
} \
static 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;
device_initialize(dev);
dev->parent = &node->dev;
dev->release = node_cache_release;
if (dev_set_name(dev, "memory_side_cache"))
goto put_device;
if (device_add(dev))
goto put_device;
pm_runtime_no_callbacks(dev);
node->cache_dev = dev;
return;
put_device:
put_device(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;
device_initialize(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 put_device;
info->cache_attrs = *cache_attrs;
if (device_add(dev)) {
dev_warn(&node->dev, "failed to add cache level:%d\n",
cache_attrs->level);
goto put_device;
}
pm_runtime_no_callbacks(dev);
list_add_tail(&info->node, &node->cache_attrs);
return;
put_device:
put_device(dev);
}
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 SecPageTables: %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, K(node_page_state(pgdat, NR_SECONDARY_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)
{
fold_vm_numa_events();
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_event_state(dev->id, NUMA_HIT),
sum_zone_numa_event_state(dev->id, NUMA_MISS),
sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
sum_zone_numa_event_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
fold_vm_numa_events();
for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
len += sysfs_emit_at(buf, len, "%s %lu\n",
numa_stat_name(i),
sum_zone_numa_event_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_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
NULL
};
static struct bin_attribute *node_dev_bin_attrs[] = {
&bin_attr_cpumap,
&bin_attr_cpulist,
NULL
};
static const struct attribute_group node_dev_group = {
.attrs = node_dev_attrs,
.bin_attrs = node_dev_bin_attrs
};
static const struct attribute_group *node_dev_groups[] = {
&node_dev_group,
#ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
&arch_node_dev_group,
#endif
#ifdef CONFIG_MEMORY_FAILURE
&memory_failure_attr_group,
#endif
NULL
};
static void node_device_release(struct device *dev)
{
kfree(to_node(dev));
}
/*
* 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);
compaction_unregister_node(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 int 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
static int __ref get_nid_for_pfn(unsigned long pfn)
{
#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,
enum meminit_context context)
{
int ret;
memory_block_add_nid(mem_blk, nid, context);
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, MEMINIT_EARLY);
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, MEMINIT_HOTPLUG);
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 register_memory_blocks_under_node(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;
}
#endif /* CONFIG_MEMORY_HOTPLUG */
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);
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 const 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,
};
void __init node_dev_init(void)
{
int ret, i;
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)
panic("%s() failed to register subsystem: %d\n", __func__, ret);
/*
* Create all node devices, which will properly link the node
* to applicable memory block devices and already created cpu devices.
*/
for_each_online_node(i) {
ret = register_one_node(i);
if (ret)
panic("%s() failed to add node: %d\n", __func__, ret);
}
}
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