kernel-ark/drivers/base/node.c
Roel Kluin 4750498099 mm: get_nid_for_pfn() returns int
get_nid_for_pfn() returns int

Presumably the (nid < 0) case has never happened.

We do know that it is happening on one system while creating a symlink for
a memory section so it should also happen on the same system if
unregister_mem_sect_under_nodes() were called to remove the same symlink.

The test was actually added in response to a problem with an earlier
version reported by Yasunori Goto where one or more of the leading pages
of a memory section on the 2nd node of one of his systems was
uninitialized because I believe they coincided with a memory hole.

That earlier version did not ignore uninitialized pages and determined
the nid by considering only the 1st page of each memory section.  This
caused the symlink to the 1st memory section on the 2nd node to be
incorrectly created in /sys/devices/system/node/node0 instead of
/sys/devices/system/node/node1.  The problem was fixed by adding the
test to skip over uninitialized pages.

I suspect we have not seen any reports of the non-removal
of a symlink due to the incorrect declaration of the nid
variable in unregister_mem_sect_under_nodes() because
  - systems where a memory section could have an uninitialized
    range of leading pages are probably rare.
  - memory remove is probably not done very frequently on the
    systems that are capable of demonstrating the problem.
  - lingering symlink(s) that should have been removed may
    have simply gone unnoticed.

[garyhade@us.ibm.com: wrote changelog]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10 15:55:10 -07:00

477 lines
12 KiB
C

/*
* drivers/base/node.c - basic Node class support
*/
#include <linux/sysdev.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/cpumask.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/swap.h>
static struct sysdev_class node_class = {
.name = "node",
};
static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
{
struct node *node_dev = to_node(dev);
node_to_cpumask_ptr(mask, node_dev->sysdev.id);
int len;
/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
len = type?
cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
buf[len++] = '\n';
buf[len] = '\0';
return len;
}
static inline ssize_t node_read_cpumask(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
return node_read_cpumap(dev, 0, buf);
}
static inline ssize_t node_read_cpulist(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
return node_read_cpumap(dev, 1, buf);
}
static SYSDEV_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL);
static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
#define K(x) ((x) << (PAGE_SHIFT - 10))
static ssize_t node_read_meminfo(struct sys_device * dev,
struct sysdev_attribute *attr, char * buf)
{
int n;
int nid = dev->id;
struct sysinfo i;
si_meminfo_node(&i, nid);
n = sprintf(buf, "\n"
"Node %d MemTotal: %8lu kB\n"
"Node %d MemFree: %8lu kB\n"
"Node %d MemUsed: %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"
#ifdef CONFIG_UNEVICTABLE_LRU
"Node %d Unevictable: %8lu kB\n"
"Node %d Mlocked: %8lu kB\n"
#endif
#ifdef CONFIG_HIGHMEM
"Node %d HighTotal: %8lu kB\n"
"Node %d HighFree: %8lu kB\n"
"Node %d LowTotal: %8lu kB\n"
"Node %d LowFree: %8lu kB\n"
#endif
"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 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 Slab: %8lu kB\n"
"Node %d SReclaimable: %8lu kB\n"
"Node %d SUnreclaim: %8lu kB\n",
nid, K(i.totalram),
nid, K(i.freeram),
nid, K(i.totalram - i.freeram),
nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
node_page_state(nid, NR_ACTIVE_FILE)),
nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
node_page_state(nid, NR_INACTIVE_FILE)),
nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
#ifdef CONFIG_UNEVICTABLE_LRU
nid, K(node_page_state(nid, NR_UNEVICTABLE)),
nid, K(node_page_state(nid, NR_MLOCK)),
#endif
#ifdef CONFIG_HIGHMEM
nid, K(i.totalhigh),
nid, K(i.freehigh),
nid, K(i.totalram - i.totalhigh),
nid, K(i.freeram - i.freehigh),
#endif
nid, K(node_page_state(nid, NR_FILE_DIRTY)),
nid, K(node_page_state(nid, NR_WRITEBACK)),
nid, K(node_page_state(nid, NR_FILE_PAGES)),
nid, K(node_page_state(nid, NR_FILE_MAPPED)),
nid, K(node_page_state(nid, NR_ANON_PAGES)),
nid, K(node_page_state(nid, NR_PAGETABLE)),
nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
nid, K(node_page_state(nid, NR_BOUNCE)),
nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
n += hugetlb_report_node_meminfo(nid, buf + n);
return n;
}
#undef K
static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
static ssize_t node_read_numastat(struct sys_device * dev,
struct sysdev_attribute *attr, char * buf)
{
return sprintf(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",
node_page_state(dev->id, NUMA_HIT),
node_page_state(dev->id, NUMA_MISS),
node_page_state(dev->id, NUMA_FOREIGN),
node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
node_page_state(dev->id, NUMA_LOCAL),
node_page_state(dev->id, NUMA_OTHER));
}
static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
static ssize_t node_read_distance(struct sys_device * dev,
struct sysdev_attribute *attr, char * buf)
{
int nid = dev->id;
int len = 0;
int i;
/* buf currently PAGE_SIZE, need ~4 chars per node */
BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2);
for_each_online_node(i)
len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
len += sprintf(buf + len, "\n");
return len;
}
static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
/*
* register_node - Setup a sysfs device for a node.
* @num - Node number to use when creating the device.
*
* Initialize and register the node device.
*/
int register_node(struct node *node, int num, struct node *parent)
{
int error;
node->sysdev.id = num;
node->sysdev.cls = &node_class;
error = sysdev_register(&node->sysdev);
if (!error){
sysdev_create_file(&node->sysdev, &attr_cpumap);
sysdev_create_file(&node->sysdev, &attr_cpulist);
sysdev_create_file(&node->sysdev, &attr_meminfo);
sysdev_create_file(&node->sysdev, &attr_numastat);
sysdev_create_file(&node->sysdev, &attr_distance);
scan_unevictable_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)
{
sysdev_remove_file(&node->sysdev, &attr_cpumap);
sysdev_remove_file(&node->sysdev, &attr_cpulist);
sysdev_remove_file(&node->sysdev, &attr_meminfo);
sysdev_remove_file(&node->sysdev, &attr_numastat);
sysdev_remove_file(&node->sysdev, &attr_distance);
scan_unevictable_unregister_node(node);
sysdev_unregister(&node->sysdev);
}
struct node node_devices[MAX_NUMNODES];
/*
* register cpu under node
*/
int register_cpu_under_node(unsigned int cpu, unsigned int nid)
{
if (node_online(nid)) {
struct sys_device *obj = get_cpu_sysdev(cpu);
if (!obj)
return 0;
return sysfs_create_link(&node_devices[nid].sysdev.kobj,
&obj->kobj,
kobject_name(&obj->kobj));
}
return 0;
}
int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
{
if (node_online(nid)) {
struct sys_device *obj = get_cpu_sysdev(cpu);
if (obj)
sysfs_remove_link(&node_devices[nid].sysdev.kobj,
kobject_name(&obj->kobj));
}
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
#define page_initialized(page) (page->lru.next)
static int get_nid_for_pfn(unsigned long pfn)
{
struct page *page;
if (!pfn_valid_within(pfn))
return -1;
page = pfn_to_page(pfn);
if (!page_initialized(page))
return -1;
return pfn_to_nid(pfn);
}
/* register memory section under specified node if it spans that node */
int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
{
unsigned long pfn, sect_start_pfn, sect_end_pfn;
if (!mem_blk)
return -EFAULT;
if (!node_online(nid))
return 0;
sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
int page_nid;
page_nid = get_nid_for_pfn(pfn);
if (page_nid < 0)
continue;
if (page_nid != nid)
continue;
return sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
&mem_blk->sysdev.kobj,
kobject_name(&mem_blk->sysdev.kobj));
}
/* mem section does not span the specified node */
return 0;
}
/* unregister memory section under all nodes that it spans */
int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
{
nodemask_t unlinked_nodes;
unsigned long pfn, sect_start_pfn, sect_end_pfn;
if (!mem_blk)
return -EFAULT;
nodes_clear(unlinked_nodes);
sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
int nid;
nid = get_nid_for_pfn(pfn);
if (nid < 0)
continue;
if (!node_online(nid))
continue;
if (node_test_and_set(nid, unlinked_nodes))
continue;
sysfs_remove_link(&node_devices[nid].sysdev.kobj,
kobject_name(&mem_blk->sysdev.kobj));
}
return 0;
}
static int link_mem_sections(int nid)
{
unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
unsigned long pfn;
int err = 0;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
unsigned long section_nr = pfn_to_section_nr(pfn);
struct mem_section *mem_sect;
struct memory_block *mem_blk;
int ret;
if (!present_section_nr(section_nr))
continue;
mem_sect = __nr_to_section(section_nr);
mem_blk = find_memory_block(mem_sect);
ret = register_mem_sect_under_node(mem_blk, nid);
if (!err)
err = ret;
/* discard ref obtained in find_memory_block() */
kobject_put(&mem_blk->sysdev.kobj);
}
return err;
}
#else
static int link_mem_sections(int nid) { return 0; }
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
int register_one_node(int nid)
{
int error = 0;
int cpu;
if (node_online(nid)) {
int p_node = parent_node(nid);
struct node *parent = NULL;
if (p_node != nid)
parent = &node_devices[p_node];
error = register_node(&node_devices[nid], nid, parent);
/* link cpu under this node */
for_each_present_cpu(cpu) {
if (cpu_to_node(cpu) == nid)
register_cpu_under_node(cpu, nid);
}
/* link memory sections under this node */
error = link_mem_sections(nid);
}
return error;
}
void unregister_one_node(int nid)
{
unregister_node(&node_devices[nid]);
}
/*
* node states attributes
*/
static ssize_t print_nodes_state(enum node_states state, char *buf)
{
int n;
n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
if (n > 0 && PAGE_SIZE > n + 1) {
*(buf + n++) = '\n';
*(buf + n++) = '\0';
}
return n;
}
static ssize_t print_nodes_possible(struct sysdev_class *class, char *buf)
{
return print_nodes_state(N_POSSIBLE, buf);
}
static ssize_t print_nodes_online(struct sysdev_class *class, char *buf)
{
return print_nodes_state(N_ONLINE, buf);
}
static ssize_t print_nodes_has_normal_memory(struct sysdev_class *class,
char *buf)
{
return print_nodes_state(N_NORMAL_MEMORY, buf);
}
static ssize_t print_nodes_has_cpu(struct sysdev_class *class, char *buf)
{
return print_nodes_state(N_CPU, buf);
}
static SYSDEV_CLASS_ATTR(possible, 0444, print_nodes_possible, NULL);
static SYSDEV_CLASS_ATTR(online, 0444, print_nodes_online, NULL);
static SYSDEV_CLASS_ATTR(has_normal_memory, 0444, print_nodes_has_normal_memory,
NULL);
static SYSDEV_CLASS_ATTR(has_cpu, 0444, print_nodes_has_cpu, NULL);
#ifdef CONFIG_HIGHMEM
static ssize_t print_nodes_has_high_memory(struct sysdev_class *class,
char *buf)
{
return print_nodes_state(N_HIGH_MEMORY, buf);
}
static SYSDEV_CLASS_ATTR(has_high_memory, 0444, print_nodes_has_high_memory,
NULL);
#endif
struct sysdev_class_attribute *node_state_attr[] = {
&attr_possible,
&attr_online,
&attr_has_normal_memory,
#ifdef CONFIG_HIGHMEM
&attr_has_high_memory,
#endif
&attr_has_cpu,
};
static int node_states_init(void)
{
int i;
int err = 0;
for (i = 0; i < NR_NODE_STATES; i++) {
int ret;
ret = sysdev_class_create_file(&node_class, node_state_attr[i]);
if (!err)
err = ret;
}
return err;
}
static int __init register_node_type(void)
{
int ret;
ret = sysdev_class_register(&node_class);
if (!ret)
ret = node_states_init();
/*
* 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);