[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/sparc64/mm/hugetlbpage.c b/arch/sparc64/mm/hugetlbpage.c
index 5a1f831..625cbb3 100644
--- a/arch/sparc64/mm/hugetlbpage.c
+++ b/arch/sparc64/mm/hugetlbpage.c
@@ -22,7 +22,7 @@
#include <asm/cacheflush.h>
#include <asm/mmu_context.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;
@@ -41,7 +41,7 @@
return pte;
}
-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;
@@ -62,32 +62,36 @@
#define mk_pte_huge(entry) do { pte_val(entry) |= _PAGE_SZHUGE; } while (0)
-static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long addr,
- struct page *page, pte_t * page_table, int write_access)
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t entry)
{
- unsigned long i;
- 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);
+ int i;
for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
- set_pte_at(mm, addr, page_table, entry);
- page_table++;
+ set_pte_at(mm, addr, ptep, entry);
+ ptep++;
addr += PAGE_SIZE;
-
pte_val(entry) += PAGE_SIZE;
}
}
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep)
+{
+ pte_t entry;
+ int i;
+
+ entry = *ptep;
+
+ for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
+ pte_clear(mm, addr, ptep);
+ addr += PAGE_SIZE;
+ ptep++;
+ }
+
+ return entry;
+}
+
/*
* This function checks for proper alignment of input addr and len parameters.
*/
@@ -100,79 +104,6 @@
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;
- int i;
-
- while (addr < end) {
- dst_pte = huge_pte_alloc(dst, addr);
- if (!dst_pte)
- goto nomem;
- src_pte = huge_pte_offset(src, addr);
- BUG_ON(!src_pte || pte_none(*src_pte));
- entry = *src_pte;
- ptepage = pte_page(entry);
- get_page(ptepage);
- for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
- set_pte_at(dst, addr, dst_pte, entry);
- pte_val(entry) += PAGE_SIZE;
- dst_pte++;
- addr += PAGE_SIZE;
- }
- add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_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 vaddr = *position;
- int remainder = *length;
-
- WARN_ON(!is_vm_hugetlb_page(vma));
-
- 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 */
- BUG_ON(!pte || pte_none(*pte));
-
- page = pte_page(*pte);
-
- WARN_ON(!PageCompound(page));
-
- get_page(page);
- pages[i] = page;
- }
-
- if (vmas)
- vmas[i] = vma;
-
- vaddr += PAGE_SIZE;
- --remainder;
- ++i;
- }
-
- *length = remainder;
- *position = vaddr;
-
- return i;
-}
-
struct page *follow_huge_addr(struct mm_struct *mm,
unsigned long address, int write)
{
@@ -190,34 +121,6 @@
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 address;
- pte_t *pte;
- struct page *page;
- int i;
-
- BUG_ON(start & (HPAGE_SIZE - 1));
- BUG_ON(end & (HPAGE_SIZE - 1));
-
- for (address = start; address < end; address += HPAGE_SIZE) {
- pte = huge_pte_offset(mm, address);
- BUG_ON(!pte);
- if (pte_none(*pte))
- continue;
- page = pte_page(*pte);
- put_page(page);
- for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
- pte_clear(mm, address+(i*PAGE_SIZE), pte);
- pte++;
- }
- }
- add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT));
- flush_tlb_range(vma, start, end);
-}
-
static void context_reload(void *__data)
{
struct mm_struct *mm = __data;
@@ -226,12 +129,8 @@
load_secondary_context(mm);
}
-int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
+void hugetlb_prefault_arch_hook(struct mm_struct *mm)
{
- struct mm_struct *mm = current->mm;
- unsigned long addr;
- int ret = 0;
-
/* On UltraSPARC-III+ and later, configure the second half of
* the Data-TLB for huge pages.
*/
@@ -261,50 +160,4 @@
}
spin_unlock(&ctx_alloc_lock);
}
-
- 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, addr, page, pte, vma->vm_flags & VM_WRITE);
- }
-out:
- spin_unlock(&mm->page_table_lock);
- return ret;
}