Re: Jffs2 and big file = very slow jffs2_garbage_collect_pass

Matthieu CASTET
2008-01-18T16:18:48Z

Josh Boyer wrote:
> On Fri, 18 Jan 2008 10:39:29 +0100
> Matthieu CASTET <matthieu.castet@parrot.com> wrote:
>
>
>> In my case the mount is ok : less than 5-10s.
>> The platform used is an arm926 @247 Mhz
>
> Ok, so running at 247MHz your board has to calculate the CRCs on 41324
> nodes before the file can be opened. I have no idea how long that
> should really take, but you're doing about 57 nodes per second if it's
> taking 12 minutes.
>
> As Jörn and David suggested, do some profiling to see where it is
> spending most of it's time.
>
I sent a mail, but because of Message has a suspicious header, the
message wait moderator approval.

In summary,
the code spend lot's of time in the rbtree code (7 minutes) and 4
minutes in jffs2_get_inode_nodes.

Matthieu

54366 rb_prev 543,6600
28345 rb_next 283,4500
8602 default_idle 71,6833
10251 __raw_readsl 40,0430
49648 jffs2_get_inode_nodes 11,8097
251 s3c2412_nand_devready 7,8438
1222 crc32_le 4,8492