Re: [PATCH 4/7] Btrfs: use a slab for ordered extents allocation

[Miao Xie <miaox@cn.fujitsu.com>]

On Wed, 5 Sep 2012 18:16:19 +0200, David Sterba wrote:
> On Wed, Aug 29, 2012 at 12:12:50PM +0800, Miao Xie wrote:
>> The ordered extent allocation is in the fast path of the IO, so use a slab
>> to improve the speed of the allocation.
> 
> Good. Size of the struct is 280, so this will fall into the size-512
> bucket, giving 8 objects per page, while own slab will pack 14 objects
> into a page.
> 
> Another benefit I see is to check for leaked objects when the
> module is removed (and the cache destroy takes place).
> 
>> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
>> ---
>>  fs/btrfs/ordered-data.c |   23 +++++++++++++++++++++--
>>  fs/btrfs/ordered-data.h |    2 ++
>>  fs/btrfs/super.c        |    9 ++++++++-
>>  3 files changed, 31 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
>> index 2eb79cc..a07ae77 100644
>> --- a/fs/btrfs/ordered-data.c
>> +++ b/fs/btrfs/ordered-data.c
>> @@ -958,3 +960,20 @@ void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
>>  	}
>>  	spin_unlock(&root->fs_info->ordered_extent_lock);
>>  }
>> +
>> +int __init ordered_data_init(void)
>> +{
>> +	ordered_extent_cache = kmem_cache_create("ordered_extent",
> 
> Please use the 'btrfs_' prefix, ie. 'btrfs_ordered_extent'

Thanks for your review. I'll update this patch by your advice.

Regards
Miao

> 
>> +				sizeof(struct btrfs_ordered_extent), 0,
>> +				SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
>> +				NULL);
>> +	if (!ordered_extent_cache)
>> +		return -ENOMEM;
>> +	return 0;
>> +}
>> +
>