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Commit c89a8bad authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[PATCH] move madvise implementation into madvise.c 

Patch from Christoph Hellwig moves the madvise implementation out of
filemap.c and into its own .c file.  No other changes are made.
parent c4be9fc7
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Showing with 342 additions and 332 deletions
mm/Makefile
View file @ c89a8bad
......@@ -16,6 +16,6 @@ obj-y := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \
vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \
page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \
shmem.o highmem.o mempool.o msync.o mincore.o readahead.o \
pdflush.o page-writeback.o rmap.o
pdflush.o page-writeback.o rmap.o madvise.o
include $(TOPDIR)/Rules.make
mm/filemap.c
View file @ c89a8bad
......@@ -1482,337 +1482,7 @@ int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
return 0;
}
static inline void setup_read_behavior(struct vm_area_struct * vma,
int behavior)
{
VM_ClearReadHint(vma);
switch(behavior) {
case MADV_SEQUENTIAL:
vma->vm_flags |= VM_SEQ_READ;
break;
case MADV_RANDOM:
vma->vm_flags |= VM_RAND_READ;
break;
default:
break;
}
return;
}
static long madvise_fixup_start(struct vm_area_struct * vma,
unsigned long end, int behavior)
{
struct vm_area_struct * n;
struct mm_struct * mm = vma->vm_mm;
n = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!n)
return -EAGAIN;
*n = *vma;
n->vm_end = end;
setup_read_behavior(n, behavior);
n->vm_raend = 0;
if (n->vm_file)
get_file(n->vm_file);
if (n->vm_ops && n->vm_ops->open)
n->vm_ops->open(n);
vma->vm_pgoff += (end - vma->vm_start) >> PAGE_SHIFT;
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_start = end;
__insert_vm_struct(mm, n);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
static long madvise_fixup_end(struct vm_area_struct * vma,
unsigned long start, int behavior)
{
struct vm_area_struct * n;
struct mm_struct * mm = vma->vm_mm;
n = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!n)
return -EAGAIN;
*n = *vma;
n->vm_start = start;
n->vm_pgoff += (n->vm_start - vma->vm_start) >> PAGE_SHIFT;
setup_read_behavior(n, behavior);
n->vm_raend = 0;
if (n->vm_file)
get_file(n->vm_file);
if (n->vm_ops && n->vm_ops->open)
n->vm_ops->open(n);
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_end = start;
__insert_vm_struct(mm, n);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
static long madvise_fixup_middle(struct vm_area_struct * vma,
unsigned long start, unsigned long end, int behavior)
{
struct vm_area_struct * left, * right;
struct mm_struct * mm = vma->vm_mm;
left = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!left)
return -EAGAIN;
right = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!right) {
kmem_cache_free(vm_area_cachep, left);
return -EAGAIN;
}
*left = *vma;
*right = *vma;
left->vm_end = start;
right->vm_start = end;
right->vm_pgoff += (right->vm_start - left->vm_start) >> PAGE_SHIFT;
left->vm_raend = 0;
right->vm_raend = 0;
if (vma->vm_file)
atomic_add(2, &vma->vm_file->f_count);
if (vma->vm_ops && vma->vm_ops->open) {
vma->vm_ops->open(left);
vma->vm_ops->open(right);
}
vma->vm_pgoff += (start - vma->vm_start) >> PAGE_SHIFT;
vma->vm_raend = 0;
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_start = start;
vma->vm_end = end;
setup_read_behavior(vma, behavior);
__insert_vm_struct(mm, left);
__insert_vm_struct(mm, right);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
/*
* We can potentially split a vm area into separate
* areas, each area with its own behavior.
*/
static long madvise_behavior(struct vm_area_struct * vma,
unsigned long start, unsigned long end, int behavior)
{
int error = 0;
/* This caps the number of vma's this process can own */
if (vma->vm_mm->map_count > MAX_MAP_COUNT)
return -ENOMEM;
if (start == vma->vm_start) {
if (end == vma->vm_end) {
setup_read_behavior(vma, behavior);
vma->vm_raend = 0;
} else
error = madvise_fixup_start(vma, end, behavior);
} else {
if (end == vma->vm_end)
error = madvise_fixup_end(vma, start, behavior);
else
error = madvise_fixup_middle(vma, start, end, behavior);
}
return error;
}
/*
* Schedule all required I/O operations, then run the disk queue
* to make sure they are started. Do not wait for completion.
*/
static long madvise_willneed(struct vm_area_struct * vma,
unsigned long start, unsigned long end)
{
long error = -EBADF;
struct file * file;
unsigned long size, rlim_rss;
/* Doesn't work if there's no mapped file. */
if (!vma->vm_file)
return error;
file = vma->vm_file;
size = (file->f_dentry->d_inode->i_size + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (end > vma->vm_end)
end = vma->vm_end;
end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
/* Make sure this doesn't exceed the process's max rss. */
error = -EIO;
rlim_rss = current->rlim ? current->rlim[RLIMIT_RSS].rlim_cur :
LONG_MAX; /* default: see resource.h */
if ((vma->vm_mm->rss + (end - start)) > rlim_rss)
return error;
do_page_cache_readahead(file, start, end - start);
return 0;
}
/*
* Application no longer needs these pages. If the pages are dirty,
* it's OK to just throw them away. The app will be more careful about
* data it wants to keep. Be sure to free swap resources too. The
* zap_page_range call sets things up for refill_inactive to actually free
* these pages later if no one else has touched them in the meantime,
* although we could add these pages to a global reuse list for
* refill_inactive to pick up before reclaiming other pages.
*
* NB: This interface discards data rather than pushes it out to swap,
* as some implementations do. This has performance implications for
* applications like large transactional databases which want to discard
* pages in anonymous maps after committing to backing store the data
* that was kept in them. There is no reason to write this data out to
* the swap area if the application is discarding it.
*
* An interface that causes the system to free clean pages and flush
* dirty pages is already available as msync(MS_INVALIDATE).
*/
static long madvise_dontneed(struct vm_area_struct * vma,
unsigned long start, unsigned long end)
{
if (vma->vm_flags & VM_LOCKED)
return -EINVAL;
zap_page_range(vma, start, end - start);
return 0;
}
static long madvise_vma(struct vm_area_struct * vma, unsigned long start,
unsigned long end, int behavior)
{
long error = -EBADF;
switch (behavior) {
case MADV_NORMAL:
case MADV_SEQUENTIAL:
case MADV_RANDOM:
error = madvise_behavior(vma, start, end, behavior);
break;
case MADV_WILLNEED:
error = madvise_willneed(vma, start, end);
break;
case MADV_DONTNEED:
error = madvise_dontneed(vma, start, end);
break;
default:
error = -EINVAL;
break;
}
return error;
}
/*
* The madvise(2) system call.
*
* Applications can use madvise() to advise the kernel how it should
* handle paging I/O in this VM area. The idea is to help the kernel
* use appropriate read-ahead and caching techniques. The information
* provided is advisory only, and can be safely disregarded by the
* kernel without affecting the correct operation of the application.
*
* behavior values:
* MADV_NORMAL - the default behavior is to read clusters. This
* results in some read-ahead and read-behind.
* MADV_RANDOM - the system should read the minimum amount of data
* on any access, since it is unlikely that the appli-
* cation will need more than what it asks for.
* MADV_SEQUENTIAL - pages in the given range will probably be accessed
* once, so they can be aggressively read ahead, and
* can be freed soon after they are accessed.
* MADV_WILLNEED - the application is notifying the system to read
* some pages ahead.
* MADV_DONTNEED - the application is finished with the given range,
* so the kernel can free resources associated with it.
*
* return values:
* zero - success
* -EINVAL - start + len < 0, start is not page-aligned,
* "behavior" is not a valid value, or application
* is attempting to release locked or shared pages.
* -ENOMEM - addresses in the specified range are not currently
* mapped, or are outside the AS of the process.
* -EIO - an I/O error occurred while paging in data.
* -EBADF - map exists, but area maps something that isn't a file.
* -EAGAIN - a kernel resource was temporarily unavailable.
*/
asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior)
{
unsigned long end;
struct vm_area_struct * vma;
int unmapped_error = 0;
int error = -EINVAL;
down_write(&current->mm->mmap_sem);
if (start & ~PAGE_MASK)
goto out;
len = (len + ~PAGE_MASK) & PAGE_MASK;
end = start + len;
if (end < start)
goto out;
error = 0;
if (end == start)
goto out;
/*
* If the interval [start,end) covers some unmapped address
* ranges, just ignore them, but return -ENOMEM at the end.
*/
vma = find_vma(current->mm, start);
for (;;) {
/* Still start < end. */
error = -ENOMEM;
if (!vma)
goto out;
/* Here start < vma->vm_end. */
if (start < vma->vm_start) {
unmapped_error = -ENOMEM;
start = vma->vm_start;
}
/* Here vma->vm_start <= start < vma->vm_end. */
if (end <= vma->vm_end) {
if (start < end) {
error = madvise_vma(vma, start, end,
behavior);
if (error)
goto out;
}
error = unmapped_error;
goto out;
}
/* Here vma->vm_start <= start < vma->vm_end < end. */
error = madvise_vma(vma, start, vma->vm_end, behavior);
if (error)
goto out;
start = vma->vm_end;
vma = vma->vm_next;
}
out:
up_write(&current->mm->mmap_sem);
return error;
}
static inline
struct page *__read_cache_page(struct address_space *mapping,
static inline struct page *__read_cache_page(struct address_space *mapping,
unsigned long index,
int (*filler)(void *,struct page*),
void *data)
......
mm/madvise.c 0 → 100644
View file @ c89a8bad
/*
* linux/mm/madvise.c
*
* Copyright (C) 1999 Linus Torvalds
*/
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
static inline void setup_read_behavior(struct vm_area_struct * vma,
int behavior)
{
VM_ClearReadHint(vma);
switch (behavior) {
case MADV_SEQUENTIAL:
vma->vm_flags |= VM_SEQ_READ;
break;
case MADV_RANDOM:
vma->vm_flags |= VM_RAND_READ;
break;
default:
break;
}
}
static long madvise_fixup_start(struct vm_area_struct * vma,
unsigned long end, int behavior)
{
struct vm_area_struct * n;
struct mm_struct * mm = vma->vm_mm;
n = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!n)
return -EAGAIN;
*n = *vma;
n->vm_end = end;
setup_read_behavior(n, behavior);
n->vm_raend = 0;
if (n->vm_file)
get_file(n->vm_file);
if (n->vm_ops && n->vm_ops->open)
n->vm_ops->open(n);
vma->vm_pgoff += (end - vma->vm_start) >> PAGE_SHIFT;
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_start = end;
__insert_vm_struct(mm, n);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
static long madvise_fixup_end(struct vm_area_struct * vma,
unsigned long start, int behavior)
{
struct vm_area_struct * n;
struct mm_struct * mm = vma->vm_mm;
n = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!n)
return -EAGAIN;
*n = *vma;
n->vm_start = start;
n->vm_pgoff += (n->vm_start - vma->vm_start) >> PAGE_SHIFT;
setup_read_behavior(n, behavior);
n->vm_raend = 0;
if (n->vm_file)
get_file(n->vm_file);
if (n->vm_ops && n->vm_ops->open)
n->vm_ops->open(n);
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_end = start;
__insert_vm_struct(mm, n);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
static long madvise_fixup_middle(struct vm_area_struct * vma, unsigned long start,
unsigned long end, int behavior)
{
struct vm_area_struct * left, * right;
struct mm_struct * mm = vma->vm_mm;
left = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!left)
return -EAGAIN;
right = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!right) {
kmem_cache_free(vm_area_cachep, left);
return -EAGAIN;
}
*left = *vma;
*right = *vma;
left->vm_end = start;
right->vm_start = end;
right->vm_pgoff += (right->vm_start - left->vm_start) >> PAGE_SHIFT;
left->vm_raend = 0;
right->vm_raend = 0;
if (vma->vm_file)
atomic_add(2, &vma->vm_file->f_count);
if (vma->vm_ops && vma->vm_ops->open) {
vma->vm_ops->open(left);
vma->vm_ops->open(right);
}
vma->vm_pgoff += (start - vma->vm_start) >> PAGE_SHIFT;
vma->vm_raend = 0;
lock_vma_mappings(vma);
spin_lock(&mm->page_table_lock);
vma->vm_start = start;
vma->vm_end = end;
setup_read_behavior(vma, behavior);
__insert_vm_struct(mm, left);
__insert_vm_struct(mm, right);
spin_unlock(&mm->page_table_lock);
unlock_vma_mappings(vma);
return 0;
}
/*
* We can potentially split a vm area into separate
* areas, each area with its own behavior.
*/
static long madvise_behavior(struct vm_area_struct * vma, unsigned long start,
unsigned long end, int behavior)
{
int error = 0;
/* This caps the number of vma's this process can own */
if (vma->vm_mm->map_count > MAX_MAP_COUNT)
return -ENOMEM;
if (start == vma->vm_start) {
if (end == vma->vm_end) {
setup_read_behavior(vma, behavior);
vma->vm_raend = 0;
} else
error = madvise_fixup_start(vma, end, behavior);
} else {
if (end == vma->vm_end)
error = madvise_fixup_end(vma, start, behavior);
else
error = madvise_fixup_middle(vma, start, end, behavior);
}
return error;
}
/*
* Schedule all required I/O operations, then run the disk queue
* to make sure they are started. Do not wait for completion.
*/
static long madvise_willneed(struct vm_area_struct * vma,
unsigned long start, unsigned long end)
{
long error = -EBADF;
struct file * file;
unsigned long size, rlim_rss;
/* Doesn't work if there's no mapped file. */
if (!vma->vm_file)
return error;
file = vma->vm_file;
size = (file->f_dentry->d_inode->i_size + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (end > vma->vm_end)
end = vma->vm_end;
end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
/* Make sure this doesn't exceed the process's max rss. */
error = -EIO;
rlim_rss = current->rlim ? current->rlim[RLIMIT_RSS].rlim_cur :
LONG_MAX; /* default: see resource.h */
if ((vma->vm_mm->rss + (end - start)) > rlim_rss)
return error;
do_page_cache_readahead(file, start, end - start);
return 0;
}
/*
* Application no longer needs these pages. If the pages are dirty,
* it's OK to just throw them away. The app will be more careful about
* data it wants to keep. Be sure to free swap resources too. The
* zap_page_range call sets things up for refill_inactive to actually free
* these pages later if no one else has touched them in the meantime,
* although we could add these pages to a global reuse list for
* refill_inactive to pick up before reclaiming other pages.
*
* NB: This interface discards data rather than pushes it out to swap,
* as some implementations do. This has performance implications for
* applications like large transactional databases which want to discard
* pages in anonymous maps after committing to backing store the data
* that was kept in them. There is no reason to write this data out to
* the swap area if the application is discarding it.
*
* An interface that causes the system to free clean pages and flush
* dirty pages is already available as msync(MS_INVALIDATE).
*/
static long madvise_dontneed(struct vm_area_struct * vma,
unsigned long start, unsigned long end)
{
if (vma->vm_flags & VM_LOCKED)
return -EINVAL;
zap_page_range(vma, start, end - start);
return 0;
}
static long madvise_vma(struct vm_area_struct * vma, unsigned long start,
unsigned long end, int behavior)
{
long error = -EBADF;
switch (behavior) {
case MADV_NORMAL:
case MADV_SEQUENTIAL:
case MADV_RANDOM:
error = madvise_behavior(vma, start, end, behavior);
break;
case MADV_WILLNEED:
error = madvise_willneed(vma, start, end);
break;
case MADV_DONTNEED:
error = madvise_dontneed(vma, start, end);
break;
default:
error = -EINVAL;
break;
}
return error;
}
/*
* The madvise(2) system call.
*
* Applications can use madvise() to advise the kernel how it should
* handle paging I/O in this VM area. The idea is to help the kernel
* use appropriate read-ahead and caching techniques. The information
* provided is advisory only, and can be safely disregarded by the
* kernel without affecting the correct operation of the application.
*
* behavior values:
* MADV_NORMAL - the default behavior is to read clusters. This
* results in some read-ahead and read-behind.
* MADV_RANDOM - the system should read the minimum amount of data
* on any access, since it is unlikely that the appli-
* cation will need more than what it asks for.
* MADV_SEQUENTIAL - pages in the given range will probably be accessed
* once, so they can be aggressively read ahead, and
* can be freed soon after they are accessed.
* MADV_WILLNEED - the application is notifying the system to read
* some pages ahead.
* MADV_DONTNEED - the application is finished with the given range,
* so the kernel can free resources associated with it.
*
* return values:
* zero - success
* -EINVAL - start + len < 0, start is not page-aligned,
* "behavior" is not a valid value, or application
* is attempting to release locked or shared pages.
* -ENOMEM - addresses in the specified range are not currently
* mapped, or are outside the AS of the process.
* -EIO - an I/O error occurred while paging in data.
* -EBADF - map exists, but area maps something that isn't a file.
* -EAGAIN - a kernel resource was temporarily unavailable.
*/
asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior)
{
unsigned long end;
struct vm_area_struct * vma;
int unmapped_error = 0;
int error = -EINVAL;
down_write(&current->mm->mmap_sem);
if (start & ~PAGE_MASK)
goto out;
len = (len + ~PAGE_MASK) & PAGE_MASK;
end = start + len;
if (end < start)
goto out;
error = 0;
if (end == start)
goto out;
/*
* If the interval [start,end) covers some unmapped address
* ranges, just ignore them, but return -ENOMEM at the end.
*/
vma = find_vma(current->mm, start);
for (;;) {
/* Still start < end. */
error = -ENOMEM;
if (!vma)
goto out;
/* Here start < vma->vm_end. */
if (start < vma->vm_start) {
unmapped_error = -ENOMEM;
start = vma->vm_start;
}
/* Here vma->vm_start <= start < vma->vm_end. */
if (end <= vma->vm_end) {
if (start < end) {
error = madvise_vma(vma, start, end,
behavior);
if (error)
goto out;
}
error = unmapped_error;
goto out;
}
/* Here vma->vm_start <= start < vma->vm_end < end. */
error = madvise_vma(vma, start, vma->vm_end, behavior);
if (error)
goto out;
start = vma->vm_end;
vma = vma->vm_next;
}
out:
up_write(&current->mm->mmap_sem);
return error;
}
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