[Bug 16380] ext2/ext4 filesystem "hangs" for a few seconds when trying to write a lot of data to a freshly RW mounted FS

https://bugzilla.kernel.org/show_bug.cgi?id=16380

--- Comment #14 from Artem S. Tashkinov <t.artem@mailcity.com>  2012-08-04 18:51:24 ---

(In reply to comment #12)

I wasn't able to duplicate this with an underlying ext4 file system, with the
loop file system being ext2, using a 3.5 kernel on a system with 16G.

I tried both using a variety of small and medium sized files, as well as one
very large file, and I didn't see any unexplained stuttering in write
bandwidth.   (There were times when cp -r was clearly writing to the in-memory
page cache, and the writeback hadn't begone yet.   There were also times when
we couldn't do any more writing, because we were busy reading from the source
drive.  But it all looked pretty normal to me.)

Hm, I cannot reproduce the problem with a loop device on top of tmpfs either,
but I've just checked my 250GB ext4 partition and the bug is still there:

When I try to copy a 3GB file (residing in tmpfs so it's all cached) to it,
there's a 4 (four) seconds delay before a single byte gets written to the
destination partition. After that all consequent files get written without any
delays.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.