Re: [PATCH] ext4: remove unnecessary operation in ext4_mb_regular_allocator()

["Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com>]

On Tue, 23 Mar 2010 20:40:29 +0800, jing zhang <zj.barak@gmail.com> wrote:
> 2010/3/23, tytso@mit.edu <tytso@mit.edu>:
> > On Mon, Mar 22, 2010 at 10:35:54PM +0800, jing zhang wrote:
> >> From: Jing Zhang <zj.barak@gmail.com>
> >>
> >> Date: Mon Mar 22 22:20:38     2010
> >>
> >> 1, In one of the hot functions in mballoc.c, unnecessary operation on
> >>        struct ext4_group_desc *desc;
> >>     is removed.
> 
> ---
> 
> diff --git a/linux-2.6.32/fs/ext4/mballoc.c b/ext4_mm_leak/mballoc5.c
> index bba1282..fb18199 100644
> --- a/linux-2.6.32/fs/ext4/mballoc.c
> +++ b/ext4_mm_leak/mballoc5.c
> @@ -2027,7 +2027,6 @@ repeat:
> 
>  		for (i = 0; i < ngroups; group++, i++) {
>  			struct ext4_group_info *grp;
> -			struct ext4_group_desc *desc;
> 
>  			if (group == ngroups)
>  				group = 0;
> @@ -2050,7 +2049,6 @@ repeat:
>  			}
> 
>  			ac->ac_groups_scanned++;
> -			desc = ext4_get_group_desc(sb, group, NULL);
>  			if (cr == 0)
>  				ext4_mb_simple_scan_group(ac, &e4b);
>  			else if (cr == 1 &&
> 


We missed that in commit 75507efb1372b6acf1aa6bf00ebd49ce196fd994
ealier we had an uninit check around that. 


-aneesh