[PATCH] Deinline a few functions in mmap.c

From: Denys Vlasenko
Date: Sat Jul 05 2008 - 12:37:44 EST

__vma_link_file and expand_downwards functions are not small,
yeat they are marked inline. They probably had one callsite
sometime in the past, but now they have more.
In order to prevent similar thing, I also deinlined
expand_upwards, despite it having only pne callsite.
Nowadays gcc auto-inlines such static functions anyway.
In find_extend_vma, I removed one extra level of indirection.

Patch is deliberately generated with -U $BIGNUM to make
it easier to see that functions are big.

Result:

# size */*/mmap.o */vmlinux
text data bss dec hex filename
9514 188 16 9718 25f6 0.org/mm/mmap.o
9237 188 16 9441 24e1 deinline/mm/mmap.o
6124402 858996 389480 7372878 70804e 0.org/vmlinux
6124113 858996 389480 7372589 707f2d deinline/vmlinux

Signed-off-by: Denys Vlasenko <vda.linux@xxxxxxxxxxxxxx>
--
vda

--- 0.org/mm/mmap.c Wed Jul 2 00:40:52 2008
+++ deinline/mm/mmap.c Sat Jul 5 16:19:30 2008
@@ -389,41 +389,41 @@
if (prev) {
vma->vm_next = prev->vm_next;
prev->vm_next = vma;
} else {
mm->mmap = vma;
if (rb_parent)
vma->vm_next = rb_entry(rb_parent,
struct vm_area_struct, vm_rb);
else
vma->vm_next = NULL;
}
}

void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
struct rb_node **rb_link, struct rb_node *rb_parent)
{
rb_link_node(&vma->vm_rb, rb_parent, rb_link);
rb_insert_color(&vma->vm_rb, &mm->mm_rb);
}

-static inline void __vma_link_file(struct vm_area_struct *vma)
+static void __vma_link_file(struct vm_area_struct *vma)
{
struct file * file;

file = vma->vm_file;
if (file) {
struct address_space *mapping = file->f_mapping;

if (vma->vm_flags & VM_DENYWRITE)
atomic_dec(&file->f_path.dentry->d_inode->i_writecount);
if (vma->vm_flags & VM_SHARED)
mapping->i_mmap_writable++;

flush_dcache_mmap_lock(mapping);
if (unlikely(vma->vm_flags & VM_NONLINEAR))
vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
else
vma_prio_tree_insert(vma, &mapping->i_mmap);
flush_dcache_mmap_unlock(mapping);
}
}
@@ -1558,41 +1558,41 @@
* Overcommit.. This must be the final test, as it will
* update security statistics.
*/
if (security_vm_enough_memory(grow))
return -ENOMEM;

/* Ok, everything looks good - let it rip */
mm->total_vm += grow;
if (vma->vm_flags & VM_LOCKED)
mm->locked_vm += grow;
vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow);
return 0;
}

#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64)
/*
* PA-RISC uses this for its stack; IA64 for its Register Backing Store.
* vma is the last one with address > vma->vm_end. Have to extend vma.
*/
#ifndef CONFIG_IA64
-static inline
+static
#endif
int expand_upwards(struct vm_area_struct *vma, unsigned long address)
{
int error;

if (!(vma->vm_flags & VM_GROWSUP))
return -EFAULT;

/*
* We must make sure the anon_vma is allocated
* so that the anon_vma locking is not a noop.
*/
if (unlikely(anon_vma_prepare(vma)))
return -ENOMEM;
anon_vma_lock(vma);

/*
* vma->vm_start/vm_end cannot change under us because the caller
* is required to hold the mmap_sem in read mode. We need the
* anon_vma lock to serialize against concurrent expand_stacks.
@@ -1608,41 +1608,41 @@

/* Somebody else might have raced and expanded it already */
if (address > vma->vm_end) {
unsigned long size, grow;

size = address - vma->vm_start;
grow = (address - vma->vm_end) >> PAGE_SHIFT;

error = acct_stack_growth(vma, size, grow);
if (!error)
vma->vm_end = address;
}
anon_vma_unlock(vma);
return error;
}
#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */

/*
* vma is the first one with address < vma->vm_start. Have to extend vma.
*/
-static inline int expand_downwards(struct vm_area_struct *vma,
+static int expand_downwards(struct vm_area_struct *vma,
unsigned long address)
{
int error;

/*
* We must make sure the anon_vma is allocated
* so that the anon_vma locking is not a noop.
*/
if (unlikely(anon_vma_prepare(vma)))
return -ENOMEM;

address &= PAGE_MASK;
error = security_file_mmap(NULL, 0, 0, 0, address, 1);
if (error)
return error;

anon_vma_lock(vma);

/*
* vma->vm_start/vm_end cannot change under us because the caller
@@ -1670,68 +1670,68 @@
int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address)
{
return expand_downwards(vma, address);
}

#ifdef CONFIG_STACK_GROWSUP
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{
return expand_upwards(vma, address);
}

struct vm_area_struct *
find_extend_vma(struct mm_struct *mm, unsigned long addr)
{
struct vm_area_struct *vma, *prev;

addr &= PAGE_MASK;
vma = find_vma_prev(mm, addr, &prev);
if (vma && (vma->vm_start <= addr))
return vma;
- if (!prev || expand_stack(prev, addr))
+ if (!prev || expand_upwards(prev, addr))
return NULL;
if (prev->vm_flags & VM_LOCKED)
make_pages_present(addr, prev->vm_end);
return prev;
}
#else
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{
return expand_downwards(vma, address);
}

struct vm_area_struct *
find_extend_vma(struct mm_struct * mm, unsigned long addr)
{
struct vm_area_struct * vma;
unsigned long start;

addr &= PAGE_MASK;
vma = find_vma(mm,addr);
if (!vma)
return NULL;
if (vma->vm_start <= addr)
return vma;
if (!(vma->vm_flags & VM_GROWSDOWN))
return NULL;
start = vma->vm_start;
- if (expand_stack(vma, addr))
+ if (expand_downwards(vma, addr))
return NULL;
if (vma->vm_flags & VM_LOCKED)
make_pages_present(addr, start);
return vma;
}
#endif

/*
* Ok - we have the memory areas we should free on the vma list,
* so release them, and do the vma updates.
*
* Called with the mm semaphore held.
*/
static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
{
/* Update high watermark before we lower total_vm */
update_hiwater_vm(mm);
do {
long nrpages = vma_pages(vma);

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