[PATCH] jbd: use kmem_cache_zalloc for allocating journal head

[PATCH] jbd: use kmem_cache_zalloc for allocating journal head

[Zheng Liu]

From: Zheng Liu <wenqing.lz@taobao.com>

This commit tries to use kmem_cache_zalloc instead of kmem_cache_alloc/
memset when a new journal head is alloctated.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: Jan Kara <jack@suse.cz>
---
Hi Jan,

This patch could be folded into the commit that you have applied:
  jbd: use kmem_cache_zalloc instead of kmem_cache_alloc/memset

Regards,
						- Zheng

 fs/jbd/journal.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 81cc7ea..c5a6926 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -1845,7 +1845,7 @@ static struct journal_head *journal_alloc_journal_head(void)
 #ifdef CONFIG_JBD_DEBUG
 	atomic_inc(&nr_journal_heads);
 #endif
-	ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
+	ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
 	if (ret == NULL) {
 		jbd_debug(1, "out of memory for journal_head\n");
 		printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n",
@@ -1853,7 +1853,7 @@ static struct journal_head *journal_alloc_journal_head(void)
 
 		while (ret == NULL) {
 			yield();
-			ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
+			ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
 		}
 	}
 	return ret;
@@ -1915,10 +1915,8 @@ struct journal_head *journal_add_journal_head(struct buffer_head *bh)
 	struct journal_head *new_jh = NULL;
 
 repeat:
-	if (!buffer_jbd(bh)) {
+	if (!buffer_jbd(bh))
 		new_jh = journal_alloc_journal_head();
-		memset(new_jh, 0, sizeof(*new_jh));
-	}
 
 	jbd_lock_bh_journal_head(bh);
 	if (buffer_jbd(bh)) {
-- 
1.7.12.rc2.18.g61b472e

Re: [PATCH] jbd: use kmem_cache_zalloc for allocating journal head

[Jan Kara]

On Mon 29-04-13 17:08:51, Zheng Liu wrote:
> From: Zheng Liu <wenqing.lz@taobao.com>
> 
> This commit tries to use kmem_cache_zalloc instead of kmem_cache_alloc/
> memset when a new journal head is alloctated.
  Thanks. Merged.

								Honza
> 
> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
> Cc: Jan Kara <jack@suse.cz>
> ---
> Hi Jan,
> 
> This patch could be folded into the commit that you have applied:
>   jbd: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
> 
> Regards,
> 						- Zheng
> 
>  fs/jbd/journal.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
> index 81cc7ea..c5a6926 100644
> --- a/fs/jbd/journal.c
> +++ b/fs/jbd/journal.c
> @@ -1845,7 +1845,7 @@ static struct journal_head *journal_alloc_journal_head(void)
>  #ifdef CONFIG_JBD_DEBUG
>  	atomic_inc(&nr_journal_heads);
>  #endif
> -	ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
> +	ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
>  	if (ret == NULL) {
>  		jbd_debug(1, "out of memory for journal_head\n");
>  		printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n",
> @@ -1853,7 +1853,7 @@ static struct journal_head *journal_alloc_journal_head(void)
>  
>  		while (ret == NULL) {
>  			yield();
> -			ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
> +			ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
>  		}
>  	}
>  	return ret;
> @@ -1915,10 +1915,8 @@ struct journal_head *journal_add_journal_head(struct buffer_head *bh)
>  	struct journal_head *new_jh = NULL;
>  
>  repeat:
> -	if (!buffer_jbd(bh)) {
> +	if (!buffer_jbd(bh))
>  		new_jh = journal_alloc_journal_head();
> -		memset(new_jh, 0, sizeof(*new_jh));
> -	}
>  
>  	jbd_lock_bh_journal_head(bh);
>  	if (buffer_jbd(bh)) {
> -- 
> 1.7.12.rc2.18.g61b472e
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR