On Wed, 18 Aug 2010 08:09:41 -0400, Chris Mason wrote:
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?
I'm looking at it now, which kernel were you on? We do spend some CPU
time on the btree but it shouldn't be a big bottleneck compared to the
disk.
I tested it on v2.6.35 kernel.
Regards
Miao Xie
This should be very similar to the performance regression that Steve
Pratt hit. Our deletion time has always been slower than ext4, but the
creation time should be the same or faster.
-chris
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