[PATCH] Hugepage consolidation
A lot of the code in arch/*/mm/hugetlbpage.c is quite similar. This patch
attempts to consolidate a lot of the code across the arch's, putting the
combined version in mm/hugetlb.c. There are a couple of uglyish hacks in
order to covert all the hugepage archs, but the result is a very large
reduction in the total amount of code. It also means things like hugepage
lazy allocation could be implemented in one place, instead of six.
Tested, at least a little, on ppc64, i386 and x86_64.
Notes:
- this patch changes the meaning of set_huge_pte() to be more
analagous to set_pte()
- does SH4 need s special huge_ptep_get_and_clear()??
Acked-by: William Lee Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ppc64/mm/hugetlbpage.c b/arch/ppc64/mm/hugetlbpage.c
index d3bf86a..b4ab766 100644
--- a/arch/ppc64/mm/hugetlbpage.c
+++ b/arch/ppc64/mm/hugetlbpage.c
@@ -121,7 +121,7 @@
return hugepte_offset(dir, addr);
}
-static pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
pud_t *pud;
@@ -134,7 +134,7 @@
return hugepte_offset(pud, addr);
}
-static pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
pud_t *pud;
@@ -147,25 +147,6 @@
return hugepte_alloc(mm, pud, addr);
}
-static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long addr, struct page *page,
- pte_t *ptep, int write_access)
-{
- pte_t entry;
-
- add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
- if (write_access) {
- entry =
- pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
- } else {
- entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
- }
- entry = pte_mkyoung(entry);
- entry = pte_mkhuge(entry);
-
- set_pte_at(mm, addr, ptep, entry);
-}
-
/*
* This function checks for proper alignment of input addr and len parameters.
*/
@@ -259,80 +240,6 @@
return -EINVAL;
}
-int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
- struct vm_area_struct *vma)
-{
- pte_t *src_pte, *dst_pte, entry;
- struct page *ptepage;
- unsigned long addr = vma->vm_start;
- unsigned long end = vma->vm_end;
- int err = -ENOMEM;
-
- while (addr < end) {
- dst_pte = huge_pte_alloc(dst, addr);
- if (!dst_pte)
- goto out;
-
- src_pte = huge_pte_offset(src, addr);
- entry = *src_pte;
-
- ptepage = pte_page(entry);
- get_page(ptepage);
- add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
- set_pte_at(dst, addr, dst_pte, entry);
-
- addr += HPAGE_SIZE;
- }
-
- err = 0;
- out:
- return err;
-}
-
-int
-follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
- struct page **pages, struct vm_area_struct **vmas,
- unsigned long *position, int *length, int i)
-{
- unsigned long vpfn, vaddr = *position;
- int remainder = *length;
-
- WARN_ON(!is_vm_hugetlb_page(vma));
-
- vpfn = vaddr/PAGE_SIZE;
- while (vaddr < vma->vm_end && remainder) {
- if (pages) {
- pte_t *pte;
- struct page *page;
-
- pte = huge_pte_offset(mm, vaddr);
-
- /* hugetlb should be locked, and hence, prefaulted */
- WARN_ON(!pte || pte_none(*pte));
-
- page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
-
- WARN_ON(!PageCompound(page));
-
- get_page(page);
- pages[i] = page;
- }
-
- if (vmas)
- vmas[i] = vma;
-
- vaddr += PAGE_SIZE;
- ++vpfn;
- --remainder;
- ++i;
- }
-
- *length = remainder;
- *position = vaddr;
-
- return i;
-}
-
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
@@ -363,89 +270,6 @@
return NULL;
}
-void unmap_hugepage_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
-{
- struct mm_struct *mm = vma->vm_mm;
- unsigned long addr;
- pte_t *ptep;
- struct page *page;
-
- WARN_ON(!is_vm_hugetlb_page(vma));
- BUG_ON((start % HPAGE_SIZE) != 0);
- BUG_ON((end % HPAGE_SIZE) != 0);
-
- for (addr = start; addr < end; addr += HPAGE_SIZE) {
- pte_t pte;
-
- ptep = huge_pte_offset(mm, addr);
- if (!ptep || pte_none(*ptep))
- continue;
-
- pte = *ptep;
- page = pte_page(pte);
- pte_clear(mm, addr, ptep);
-
- put_page(page);
- }
- add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT));
- flush_tlb_pending();
-}
-
-int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
-{
- struct mm_struct *mm = current->mm;
- unsigned long addr;
- int ret = 0;
-
- WARN_ON(!is_vm_hugetlb_page(vma));
- BUG_ON((vma->vm_start % HPAGE_SIZE) != 0);
- BUG_ON((vma->vm_end % HPAGE_SIZE) != 0);
-
- spin_lock(&mm->page_table_lock);
- for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
- unsigned long idx;
- pte_t *pte = huge_pte_alloc(mm, addr);
- struct page *page;
-
- if (!pte) {
- ret = -ENOMEM;
- goto out;
- }
- if (! pte_none(*pte))
- continue;
-
- idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
- + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
- page = find_get_page(mapping, idx);
- if (!page) {
- /* charge the fs quota first */
- if (hugetlb_get_quota(mapping)) {
- ret = -ENOMEM;
- goto out;
- }
- page = alloc_huge_page();
- if (!page) {
- hugetlb_put_quota(mapping);
- ret = -ENOMEM;
- goto out;
- }
- ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
- if (! ret) {
- unlock_page(page);
- } else {
- hugetlb_put_quota(mapping);
- free_huge_page(page);
- goto out;
- }
- }
- set_huge_pte(mm, vma, addr, page, pte, vma->vm_flags & VM_WRITE);
- }
-out:
- spin_unlock(&mm->page_table_lock);
- return ret;
-}
-
/* Because we have an exclusive hugepage region which lies within the
* normal user address space, we have to take special measures to make
* non-huge mmap()s evade the hugepage reserved regions. */