Fix several points in objrmap's vma sorting:
1. It was adding all vmas, even private ones, to i_mmap_shared.
2. It was not quite sorting: list_add_tail is needed in all cases.
3. If vm_pgoff is changed on a file vma (as in vma_merge and split_vma)
we must unlink vma from list and relink while holding i_shared_sem:
move_vma_start to do this (holds page_table_lock too, as vma_merge
did and split_vma did not: I think nothing needs that, rip it out
if you like, but my guess was that you'd prefer the extra safety).
Sorry, no, this doesn't magically make it all a hundred times faster.
--- 2.5.67-mm1/mm/mmap.c Tue Apr 8 14:02:06 2003
+++ linux/mm/mmap.c Tue Apr 8 18:06:07 2003
@@ -321,16 +321,13 @@
else
vmhead = &mapping->i_mmap;
- list_for_each(vmlist, &mapping->i_mmap_shared) {
+ list_for_each(vmlist, vmhead) {
struct vm_area_struct *vmtemp;
vmtemp = list_entry(vmlist, struct vm_area_struct, shared);
if (vmtemp->vm_pgoff >= vma->vm_pgoff)
break;
}
- if (vmlist == vmhead)
- list_add_tail(&vma->shared, vmlist);
- else
- list_add(&vma->shared, vmlist);
+ list_add_tail(&vma->shared, vmlist);
}
}
@@ -366,6 +363,28 @@
validate_mm(mm);
}
+static void move_vma_start(struct vm_area_struct *vma, unsigned long addr)
+{
+ spinlock_t *lock = &vma->vm_mm->page_table_lock;
+ struct inode *inode = NULL;
+
+ if (vma->vm_file) {
+ inode = vma->vm_file->f_dentry->d_inode;
+ down(&inode->i_mapping->i_shared_sem);
+ }
+ spin_lock(lock);
+ if (inode)
+ __remove_shared_vm_struct(vma, inode);
+ /* If no vm_file, perhaps we should always keep vm_pgoff at 0?? */
+ vma->vm_pgoff += (long)(addr - vma->vm_start) >> PAGE_SHIFT;
+ vma->vm_start = addr;
+ if (inode) {
+ __vma_link_file(vma);
+ up(&inode->i_mapping->i_shared_sem);
+ }
+ spin_unlock(lock);
+}
+
/*
* Return true if we can merge this (vm_flags,file,vm_pgoff,size)
* in front of (at a lower virtual address and file offset than) the vma.
@@ -422,8 +441,6 @@
unsigned long end, unsigned long vm_flags,
struct file *file, unsigned long pgoff)
{
- spinlock_t * lock = &mm->page_table_lock;
-
if (!prev) {
prev = rb_entry(rb_parent, struct vm_area_struct, vm_rb);
goto merge_next;
@@ -435,6 +452,7 @@
if (prev->vm_end == addr &&
can_vma_merge_after(prev, vm_flags, file, pgoff)) {
struct vm_area_struct *next;
+ spinlock_t *lock = &mm->page_table_lock;
struct inode *inode = file ? file->f_dentry->d_inode : NULL;
int need_up = 0;
@@ -480,10 +498,7 @@
pgoff, (end - addr) >> PAGE_SHIFT))
return 0;
if (end == prev->vm_start) {
- spin_lock(lock);
- prev->vm_start = addr;
- prev->vm_pgoff -= (end - addr) >> PAGE_SHIFT;
- spin_unlock(lock);
+ move_vma_start(prev, addr);
return 1;
}
}
@@ -1203,8 +1218,7 @@
if (new_below) {
new->vm_end = addr;
- vma->vm_start = addr;
- vma->vm_pgoff += ((addr - new->vm_start) >> PAGE_SHIFT);
+ move_vma_start(vma, addr);
} else {
vma->vm_end = addr;
new->vm_start = addr;
-
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This archive was generated by hypermail 2b29 : Tue Apr 15 2003 - 22:00:15 EST