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Message-Id: <4C7FB50D0200007800013F36@vpn.id2.novell.com>
Date: Thu, 02 Sep 2010 13:30:37 +0100
From: "Jan Beulich" <JBeulich@...ell.com>
To: <linux-kernel@...r.kernel.org>
Cc: <akpm@...ux-foundation.org>
Subject: [PATCH] use clear_page()/copy_page() in favor of
memset()/memcpy() on whole pages
After all that's what they are intended for.
Signed-off-by: Jan Beulich <jbeulich@...ell.com>
---
fs/fuse/dev.c | 2 +-
kernel/kexec.c | 2 +-
kernel/power/snapshot.c | 14 +++++++-------
kernel/power/swap.c | 6 +++---
mm/memory.c | 2 +-
5 files changed, 13 insertions(+), 13 deletions(-)
--- linux-2.6.36-rc3/fs/fuse/dev.c
+++ 2.6.36-rc3-use-clear_page/fs/fuse/dev.c
@@ -811,7 +811,7 @@ static int fuse_copy_page(struct fuse_co
if (page && zeroing && count < PAGE_SIZE) {
void *mapaddr = kmap_atomic(page, KM_USER1);
- memset(mapaddr, 0, PAGE_SIZE);
+ clear_page(mapaddr);
kunmap_atomic(mapaddr, KM_USER1);
}
while (count) {
--- linux-2.6.36-rc3/kernel/kexec.c
+++ 2.6.36-rc3-use-clear_page/kernel/kexec.c
@@ -816,7 +816,7 @@ static int kimage_load_normal_segment(st
ptr = kmap(page);
/* Start with a clear page */
- memset(ptr, 0, PAGE_SIZE);
+ clear_page(ptr);
ptr += maddr & ~PAGE_MASK;
mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
if (mchunk > mbytes)
--- linux-2.6.36-rc3/kernel/power/snapshot.c
+++ 2.6.36-rc3-use-clear_page/kernel/power/snapshot.c
@@ -988,7 +988,7 @@ static void copy_data_page(unsigned long
*/
safe_copy_page(buffer, s_page);
dst = kmap_atomic(d_page, KM_USER0);
- memcpy(dst, buffer, PAGE_SIZE);
+ copy_page(dst, buffer);
kunmap_atomic(dst, KM_USER0);
} else {
safe_copy_page(page_address(d_page), s_page);
@@ -1636,7 +1636,7 @@ int snapshot_read_next(struct snapshot_h
memory_bm_position_reset(&orig_bm);
memory_bm_position_reset(©_bm);
} else if (handle->cur <= nr_meta_pages) {
- memset(buffer, 0, PAGE_SIZE);
+ clear_page(buffer);
pack_pfns(buffer, &orig_bm);
} else {
struct page *page;
@@ -1650,7 +1650,7 @@ int snapshot_read_next(struct snapshot_h
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
- memcpy(buffer, kaddr, PAGE_SIZE);
+ copy_page(buffer, kaddr);
kunmap_atomic(kaddr, KM_USER0);
handle->buffer = buffer;
} else {
@@ -1933,7 +1933,7 @@ static void copy_last_highmem_page(void)
void *dst;
dst = kmap_atomic(last_highmem_page, KM_USER0);
- memcpy(dst, buffer, PAGE_SIZE);
+ copy_page(dst, buffer);
kunmap_atomic(dst, KM_USER0);
last_highmem_page = NULL;
}
@@ -2219,9 +2219,9 @@ swap_two_pages_data(struct page *p1, str
kaddr1 = kmap_atomic(p1, KM_USER0);
kaddr2 = kmap_atomic(p2, KM_USER1);
- memcpy(buf, kaddr1, PAGE_SIZE);
- memcpy(kaddr1, kaddr2, PAGE_SIZE);
- memcpy(kaddr2, buf, PAGE_SIZE);
+ copy_page(buf, kaddr1);
+ copy_page(kaddr1, kaddr2);
+ copy_page(kaddr2, buf);
kunmap_atomic(kaddr1, KM_USER0);
kunmap_atomic(kaddr2, KM_USER1);
}
--- linux-2.6.36-rc3/kernel/power/swap.c
+++ 2.6.36-rc3-use-clear_page/kernel/power/swap.c
@@ -249,7 +249,7 @@ static int write_page(void *buf, sector_
if (bio_chain) {
src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
if (src) {
- memcpy(src, buf, PAGE_SIZE);
+ copy_page(src, buf);
} else {
WARN_ON_ONCE(1);
bio_chain = NULL; /* Go synchronous */
@@ -323,7 +323,7 @@ static int swap_write_page(struct swap_m
error = write_page(handle->cur, handle->cur_swap, NULL);
if (error)
goto out;
- memset(handle->cur, 0, PAGE_SIZE);
+ clear_page(handle->cur);
handle->cur_swap = offset;
handle->k = 0;
}
@@ -634,7 +634,7 @@ int swsusp_check(void)
hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
if (!IS_ERR(hib_resume_bdev)) {
set_blocksize(hib_resume_bdev, PAGE_SIZE);
- memset(swsusp_header, 0, PAGE_SIZE);
+ clear_page(swsusp_header);
error = hib_bio_read_page(swsusp_resume_block,
swsusp_header, NULL);
if (error)
--- linux-2.6.36-rc3/mm/memory.c
+++ 2.6.36-rc3-use-clear_page/mm/memory.c
@@ -2079,7 +2079,7 @@ static inline void cow_user_page(struct
* zeroes.
*/
if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
- memset(kaddr, 0, PAGE_SIZE);
+ clear_page(kaddr);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(dst);
} else
--
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