All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Jan Beulich" <JBeulich@novell.com>
To: <linux-kernel@vger.kernel.org>
Cc: <akpm@linux-foundation.org>
Subject: [PATCH] use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
Date: Thu, 02 Sep 2010 13:30:37 +0100	[thread overview]
Message-ID: <4C7FB50D0200007800013F36@vpn.id2.novell.com> (raw)

After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.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(&copy_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



             reply	other threads:[~2010-09-02 12:30 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-02 12:30 Jan Beulich [this message]
2010-09-14 23:06 ` [PATCH] use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages Andrew Morton
2010-09-15  0:11   ` Rafael J. Wysocki
2010-09-15  6:32   ` Miklos Szeredi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4C7FB50D0200007800013F36@vpn.id2.novell.com \
    --to=jbeulich@novell.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.