Re: Poor creat/delete files performance

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

On Wed, 18 Aug 2010 11:49:16 +0100, Leonidas Spyropoulos wrote:
> Have you tried umounting and mounting before the second test to
> eliminate any caching?

Yes, I have done it.
The result is similar to the one I have reported.
(Unit: second)
   Create file performance
		BtrFS		Ext4
   Total times:	2.484392	1.505082
   Average:	0.000050	0.000030

   Delete file performance
		BtrFS		Ext4
   Total times:	3.369469	1.024886
   Average:	0.000067	0.000020


> Which kernel you use?

v2.6.35

Regards
Miao Xie

>
> 2010/8/18 Miao Xie<miaox@cn.fujitsu.com>:
>> Hi,
>>
>> We did some performance test and found the create/delete files performance
>> of btrfs is very poor.
>>
>> The test is that we create 50000 files and measure the file-create time
>> first, and then delete these 50000 files and measure the file-delete time.
>> (The attached file is the reproduce program)
>>
>> The result is following:
>> (Unit: second)
>>   Create file performance
>>                 BtrFS           Ext4
>>   Total times:  2.462625        1.449550
>>   Average:      0.000049        0.000029
>>
>>   Delete file performance
>>                 BtrFS           Ext4
>>   Total times:  3.312796        0.997946
>>   Average:      0.000066        0.000020
>>
>> The results were measured on a x86_64 server with 4 cores and 2 SAS disks.
>> By debuging, we found the btrfs spent a lot of time on searching and
>> inserting/removing items in the ctree.
>>
>> Is anyone looking at this issue?
>>
>> Regards
>> Miao Xie
>>
>
>
>