[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/i386/mm/hugetlbpage.c b/arch/i386/mm/hugetlbpage.c
index 171fc92..5aa0600 100644
--- a/arch/i386/mm/hugetlbpage.c
+++ b/arch/i386/mm/hugetlbpage.c
@@ -18,7 +18,7 @@
#include <asm/tlb.h>
#include <asm/tlbflush.h>
-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)
{
pgd_t *pgd;
pud_t *pud;
@@ -30,7 +30,7 @@
return (pte_t *) pmd;
}
-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)
{
pgd_t *pgd;
pud_t *pud;
@@ -42,21 +42,6 @@
return (pte_t *) pmd;
}
-static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page, pte_t * page_table, 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);
- mk_pte_huge(entry);
- set_pte(page_table, entry);
-}
-
/*
* This function checks for proper alignment of input addr and len parameters.
*/
@@ -69,77 +54,6 @@
return 0;
}
-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;
-
- while (addr < end) {
- dst_pte = huge_pte_alloc(dst, addr);
- if (!dst_pte)
- goto nomem;
- src_pte = huge_pte_offset(src, addr);
- entry = *src_pte;
- ptepage = pte_page(entry);
- get_page(ptepage);
- set_pte(dst_pte, entry);
- add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
- addr += HPAGE_SIZE;
- }
- return 0;
-
-nomem:
- return -ENOMEM;
-}
-
-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;
-}
-
#if 0 /* This is just for testing */
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
@@ -204,83 +118,15 @@
}
#endif
-void unmap_hugepage_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+void hugetlb_clean_stale_pgtable(pte_t *pte)
{
- struct mm_struct *mm = vma->vm_mm;
- unsigned long address;
- pte_t pte, *ptep;
+ pmd_t *pmd = (pmd_t *) pte;
struct page *page;
- BUG_ON(start & (HPAGE_SIZE - 1));
- BUG_ON(end & (HPAGE_SIZE - 1));
-
- for (address = start; address < end; address += HPAGE_SIZE) {
- ptep = huge_pte_offset(mm, address);
- if (!ptep)
- continue;
- pte = ptep_get_and_clear(mm, address, ptep);
- if (pte_none(pte))
- continue;
- page = pte_page(pte);
- put_page(page);
- }
- add_mm_counter(mm ,rss, -((end - start) >> PAGE_SHIFT));
- flush_tlb_range(vma, start, end);
-}
-
-int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
-{
- struct mm_struct *mm = current->mm;
- unsigned long addr;
- int ret = 0;
-
- BUG_ON(vma->vm_start & ~HPAGE_MASK);
- BUG_ON(vma->vm_end & ~HPAGE_MASK);
-
- 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, page, pte, vma->vm_flags & VM_WRITE);
- }
-out:
- spin_unlock(&mm->page_table_lock);
- return ret;
+ page = pmd_page(*pmd);
+ pmd_clear(pmd);
+ dec_page_state(nr_page_table_pages);
+ page_cache_release(page);
}
/* x86_64 also uses this file */