[PATCH 03/10] hugetlb: redefine hugepage copy functions

From: Naoya Horiguchi
Date: Tue Sep 07 2010 - 21:31:47 EST


This patch modifies hugepage copy functions to have only destination
and source hugepages as arguments for later use.
The old ones are renamed from copy_{gigantic,huge}_page() to
copy_user_{gigantic,huge}_page().
This naming convention is consistent with that between copy_highpage()
and copy_user_highpage().

ChangeLog since v4:
- add blank line between local declaration and code
- remove unnecessary might_sleep()

ChangeLog since v2:
- change copy_huge_page() from macro to inline dummy function
to avoid compile warning when !CONFIG_HUGETLB_PAGE.

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 4 ++++
mm/hugetlb.c | 45 ++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 44 insertions(+), 5 deletions(-)

diff --git v2.6.36-rc2/include/linux/hugetlb.h v2.6.36-rc2/include/linux/hugetlb.h
index 0b73c53..9e51f77 100644
--- v2.6.36-rc2/include/linux/hugetlb.h
+++ v2.6.36-rc2/include/linux/hugetlb.h
@@ -44,6 +44,7 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to,
int acctflags);
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
void __isolate_hwpoisoned_huge_page(struct page *page);
+void copy_huge_page(struct page *dst, struct page *src);

extern unsigned long hugepages_treat_as_movable;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
@@ -102,6 +103,9 @@ static inline void hugetlb_report_meminfo(struct seq_file *m)
#define hugetlb_fault(mm, vma, addr, flags) ({ BUG(); 0; })
#define huge_pte_offset(mm, address) 0
#define __isolate_hwpoisoned_huge_page(page) 0
+static inline void copy_huge_page(struct page *dst, struct page *src)
+{
+}

#define hugetlb_change_protection(vma, address, end, newprot)

diff --git v2.6.36-rc2/mm/hugetlb.c v2.6.36-rc2/mm/hugetlb.c
index f526228..351f8d1 100644
--- v2.6.36-rc2/mm/hugetlb.c
+++ v2.6.36-rc2/mm/hugetlb.c
@@ -423,14 +423,14 @@ static void clear_huge_page(struct page *page,
}
}

-static void copy_gigantic_page(struct page *dst, struct page *src,
+static void copy_user_gigantic_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);
struct page *dst_base = dst;
struct page *src_base = src;
- might_sleep();
+
for (i = 0; i < pages_per_huge_page(h); ) {
cond_resched();
copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
@@ -440,14 +440,15 @@ static void copy_gigantic_page(struct page *dst, struct page *src,
src = mem_map_next(src, src_base, i);
}
}
-static void copy_huge_page(struct page *dst, struct page *src,
+
+static void copy_user_huge_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);

if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
- copy_gigantic_page(dst, src, addr, vma);
+ copy_user_gigantic_page(dst, src, addr, vma);
return;
}

@@ -458,6 +459,40 @@ static void copy_huge_page(struct page *dst, struct page *src,
}
}

+static void copy_gigantic_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+
+ for (i = 0; i < pages_per_huge_page(h); ) {
+ cond_resched();
+ copy_highpage(dst, src);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
+
+void copy_huge_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+
+ if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+ copy_gigantic_page(dst, src);
+ return;
+ }
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page(h); i++) {
+ cond_resched();
+ copy_highpage(dst + i, src + i);
+ }
+}
+
static void enqueue_huge_page(struct hstate *h, struct page *page)
{
int nid = page_to_nid(page);
@@ -2415,7 +2450,7 @@ retry_avoidcopy:
if (unlikely(anon_vma_prepare(vma)))
return VM_FAULT_OOM;

- copy_huge_page(new_page, old_page, address, vma);
+ copy_user_huge_page(new_page, old_page, address, vma);
__SetPageUptodate(new_page);

/*
--
1.7.2.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/