Date:   Thu, 9 Mar 2023 12:36:43 +0100
From:   Jan Kara <jack@suse.cz>
To:     Ojaswin Mujoo <ojaswin@linux.ibm.com>
Cc:     linux-ext4@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
        Ritesh Harjani <riteshh@linux.ibm.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jan Kara <jack@suse.cz>, Ritesh Harjani <ritesh.list@gmail.com>
Subject: Re: [RFC 01/11] ext4: mballoc: Remove useless setting of ac_criteria
Message-ID: <20230309113643.tlyyo3ssv7braw7a@quack3>
References: <cover.1674822311.git.ojaswin@linux.ibm.com>
 <08aadf4fd475d87020c60792d81276a28d7176c1.1674822311.git.ojaswin@linux.ibm.com>
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On Fri 27-01-23 18:07:28, Ojaswin Mujoo wrote:
> There will be changes coming in future patches which will introduce a new
> criteria for block allocation. This removes the useless setting of ac_criteria.
> AFAIU, this might be only used to differentiate between whether a preallocated
> blocks was allocated or was regular allocator called for allocating blocks.
> Hence this also adds the debug prints to identify what type of block allocation
> was done in ext4_mb_show_ac().
> 
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/mballoc.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 5b2ae37a8b80..572e79a698d4 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -4391,7 +4391,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
>  			atomic_inc(&pa->pa_count);
>  			ext4_mb_use_inode_pa(ac, pa);
>  			spin_unlock(&pa->pa_lock);
> -			ac->ac_criteria = 10;
>  			rcu_read_unlock();
>  			return true;
>  		}
> @@ -4434,7 +4433,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
>  	}
>  	if (cpa) {
>  		ext4_mb_use_group_pa(ac, cpa);
> -		ac->ac_criteria = 20;
>  		return true;
>  	}
>  	return false;
> @@ -5131,6 +5129,10 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
>  			(unsigned long)ac->ac_b_ex.fe_logical,
>  			(int)ac->ac_criteria);
>  	mb_debug(sb, "%u found", ac->ac_found);
> +	mb_debug(sb, "used pa: %s, ", ac->ac_pa ? "yes" : "no");
> +	if (ac->ac_pa)
> +		mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ?
> +			 "group pa" : "inode pa");
>  	ext4_mb_show_pa(sb);
>  }
>  #else
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR