linux/fs/proc/task_mmu.c
Nick Piggin ad820c5dd4 [PATCH] smaps: shared fix
The point of the smaps "shared" is to count the number of pages that are
mapped by more than one process, according to Mauricio Lin.  However, smaps
uses page_count for this, so it will return a false positive for every page
that is mapped by just that one process, which is also in pagecache or
swapcache.  There are false positive situations for anonymous pages not in
swapcache as well: - page reclaim, migration - get_user_pages (eg.
direct-io, ptrace)

Use page_mapcount instead, to count the number of mappings to the page.

Use vm_normal_page so that weird things like /dev/mem aren't counted either.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06 18:40:45 -08:00

400 lines
9.3 KiB
C

#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/mempolicy.h>
#include <asm/elf.h>
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
#include "internal.h"
char *task_mem(struct mm_struct *mm, char *buffer)
{
unsigned long data, text, lib;
unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
/*
* Note: to minimize their overhead, mm maintains hiwater_vm and
* hiwater_rss only when about to *lower* total_vm or rss. Any
* collector of these hiwater stats must therefore get total_vm
* and rss too, which will usually be the higher. Barriers? not
* worth the effort, such snapshots can always be inconsistent.
*/
hiwater_vm = total_vm = mm->total_vm;
if (hiwater_vm < mm->hiwater_vm)
hiwater_vm = mm->hiwater_vm;
hiwater_rss = total_rss = get_mm_rss(mm);
if (hiwater_rss < mm->hiwater_rss)
hiwater_rss = mm->hiwater_rss;
data = mm->total_vm - mm->shared_vm - mm->stack_vm;
text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
buffer += sprintf(buffer,
"VmPeak:\t%8lu kB\n"
"VmSize:\t%8lu kB\n"
"VmLck:\t%8lu kB\n"
"VmHWM:\t%8lu kB\n"
"VmRSS:\t%8lu kB\n"
"VmData:\t%8lu kB\n"
"VmStk:\t%8lu kB\n"
"VmExe:\t%8lu kB\n"
"VmLib:\t%8lu kB\n"
"VmPTE:\t%8lu kB\n",
hiwater_vm << (PAGE_SHIFT-10),
(total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
mm->locked_vm << (PAGE_SHIFT-10),
hiwater_rss << (PAGE_SHIFT-10),
total_rss << (PAGE_SHIFT-10),
data << (PAGE_SHIFT-10),
mm->stack_vm << (PAGE_SHIFT-10), text, lib,
(PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
return buffer;
}
unsigned long task_vsize(struct mm_struct *mm)
{
return PAGE_SIZE * mm->total_vm;
}
int task_statm(struct mm_struct *mm, int *shared, int *text,
int *data, int *resident)
{
*shared = get_mm_counter(mm, file_rss);
*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
>> PAGE_SHIFT;
*data = mm->total_vm - mm->shared_vm;
*resident = *shared + get_mm_counter(mm, anon_rss);
return mm->total_vm;
}
int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
struct vm_area_struct * vma;
int result = -ENOENT;
struct task_struct *task = proc_task(inode);
struct mm_struct * mm = get_task_mm(task);
if (!mm)
goto out;
down_read(&mm->mmap_sem);
vma = mm->mmap;
while (vma) {
if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
break;
vma = vma->vm_next;
}
if (vma) {
*mnt = mntget(vma->vm_file->f_vfsmnt);
*dentry = dget(vma->vm_file->f_dentry);
result = 0;
}
up_read(&mm->mmap_sem);
mmput(mm);
out:
return result;
}
static void pad_len_spaces(struct seq_file *m, int len)
{
len = 25 + sizeof(void*) * 6 - len;
if (len < 1)
len = 1;
seq_printf(m, "%*c", len, ' ');
}
struct mem_size_stats
{
unsigned long resident;
unsigned long shared_clean;
unsigned long shared_dirty;
unsigned long private_clean;
unsigned long private_dirty;
};
static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats *mss)
{
struct task_struct *task = m->private;
struct vm_area_struct *vma = v;
struct mm_struct *mm = vma->vm_mm;
struct file *file = vma->vm_file;
int flags = vma->vm_flags;
unsigned long ino = 0;
dev_t dev = 0;
int len;
if (file) {
struct inode *inode = vma->vm_file->f_dentry->d_inode;
dev = inode->i_sb->s_dev;
ino = inode->i_ino;
}
seq_printf(m, "%08lx-%08lx %c%c%c%c %08lx %02x:%02x %lu %n",
vma->vm_start,
vma->vm_end,
flags & VM_READ ? 'r' : '-',
flags & VM_WRITE ? 'w' : '-',
flags & VM_EXEC ? 'x' : '-',
flags & VM_MAYSHARE ? 's' : 'p',
vma->vm_pgoff << PAGE_SHIFT,
MAJOR(dev), MINOR(dev), ino, &len);
/*
* Print the dentry name for named mappings, and a
* special [heap] marker for the heap:
*/
if (file) {
pad_len_spaces(m, len);
seq_path(m, file->f_vfsmnt, file->f_dentry, "\n");
} else {
if (mm) {
if (vma->vm_start <= mm->start_brk &&
vma->vm_end >= mm->brk) {
pad_len_spaces(m, len);
seq_puts(m, "[heap]");
} else {
if (vma->vm_start <= mm->start_stack &&
vma->vm_end >= mm->start_stack) {
pad_len_spaces(m, len);
seq_puts(m, "[stack]");
}
}
} else {
pad_len_spaces(m, len);
seq_puts(m, "[vdso]");
}
}
seq_putc(m, '\n');
if (mss)
seq_printf(m,
"Size: %8lu kB\n"
"Rss: %8lu kB\n"
"Shared_Clean: %8lu kB\n"
"Shared_Dirty: %8lu kB\n"
"Private_Clean: %8lu kB\n"
"Private_Dirty: %8lu kB\n",
(vma->vm_end - vma->vm_start) >> 10,
mss->resident >> 10,
mss->shared_clean >> 10,
mss->shared_dirty >> 10,
mss->private_clean >> 10,
mss->private_dirty >> 10);
if (m->count < m->size) /* vma is copied successfully */
m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
return 0;
}
static int show_map(struct seq_file *m, void *v)
{
return show_map_internal(m, v, NULL);
}
static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
struct mem_size_stats *mss)
{
pte_t *pte, ptent;
spinlock_t *ptl;
struct page *page;
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
ptent = *pte;
if (!pte_present(ptent))
continue;
mss->resident += PAGE_SIZE;
page = vm_normal_page(vma, addr, ptent);
if (!page)
continue;
if (page_mapcount(page) >= 2) {
if (pte_dirty(ptent))
mss->shared_dirty += PAGE_SIZE;
else
mss->shared_clean += PAGE_SIZE;
} else {
if (pte_dirty(ptent))
mss->private_dirty += PAGE_SIZE;
else
mss->private_clean += PAGE_SIZE;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(pte - 1, ptl);
cond_resched();
}
static inline void smaps_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
struct mem_size_stats *mss)
{
pmd_t *pmd;
unsigned long next;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
smaps_pte_range(vma, pmd, addr, next, mss);
} while (pmd++, addr = next, addr != end);
}
static inline void smaps_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
unsigned long addr, unsigned long end,
struct mem_size_stats *mss)
{
pud_t *pud;
unsigned long next;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
smaps_pmd_range(vma, pud, addr, next, mss);
} while (pud++, addr = next, addr != end);
}
static inline void smaps_pgd_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
struct mem_size_stats *mss)
{
pgd_t *pgd;
unsigned long next;
pgd = pgd_offset(vma->vm_mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
smaps_pud_range(vma, pgd, addr, next, mss);
} while (pgd++, addr = next, addr != end);
}
static int show_smap(struct seq_file *m, void *v)
{
struct vm_area_struct *vma = v;
struct mem_size_stats mss;
memset(&mss, 0, sizeof mss);
if (vma->vm_mm && !is_vm_hugetlb_page(vma))
smaps_pgd_range(vma, vma->vm_start, vma->vm_end, &mss);
return show_map_internal(m, v, &mss);
}
static void *m_start(struct seq_file *m, loff_t *pos)
{
struct task_struct *task = m->private;
unsigned long last_addr = m->version;
struct mm_struct *mm;
struct vm_area_struct *vma, *tail_vma;
loff_t l = *pos;
/*
* We remember last_addr rather than next_addr to hit with
* mmap_cache most of the time. We have zero last_addr at
* the beginning and also after lseek. We will have -1 last_addr
* after the end of the vmas.
*/
if (last_addr == -1UL)
return NULL;
mm = get_task_mm(task);
if (!mm)
return NULL;
tail_vma = get_gate_vma(task);
down_read(&mm->mmap_sem);
/* Start with last addr hint */
if (last_addr && (vma = find_vma(mm, last_addr))) {
vma = vma->vm_next;
goto out;
}
/*
* Check the vma index is within the range and do
* sequential scan until m_index.
*/
vma = NULL;
if ((unsigned long)l < mm->map_count) {
vma = mm->mmap;
while (l-- && vma)
vma = vma->vm_next;
goto out;
}
if (l != mm->map_count)
tail_vma = NULL; /* After gate vma */
out:
if (vma)
return vma;
/* End of vmas has been reached */
m->version = (tail_vma != NULL)? 0: -1UL;
up_read(&mm->mmap_sem);
mmput(mm);
return tail_vma;
}
static void m_stop(struct seq_file *m, void *v)
{
struct task_struct *task = m->private;
struct vm_area_struct *vma = v;
if (vma && vma != get_gate_vma(task)) {
struct mm_struct *mm = vma->vm_mm;
up_read(&mm->mmap_sem);
mmput(mm);
}
}
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
struct task_struct *task = m->private;
struct vm_area_struct *vma = v;
struct vm_area_struct *tail_vma = get_gate_vma(task);
(*pos)++;
if (vma && (vma != tail_vma) && vma->vm_next)
return vma->vm_next;
m_stop(m, v);
return (vma != tail_vma)? tail_vma: NULL;
}
struct seq_operations proc_pid_maps_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_map
};
struct seq_operations proc_pid_smaps_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_smap
};
#ifdef CONFIG_NUMA
extern int show_numa_map(struct seq_file *m, void *v);
struct seq_operations proc_pid_numa_maps_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_numa_map
};
#endif