Re: Pause intervals when copying/extracting an archive

[Ryusuke Konishi <ryusuke-sG5X7nlA6pw@public.gmane.org>]

On Sun, 07 Jun 2009 00:11:13 +0900 (JST), Ryusuke Konishi wrote:
> Hi,
> On Sat, 6 Jun 2009 16:49:28 +0300, nezmer-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
> > On Sat, Jun 06, 2009 at 04:56:53AM +0900, Ryusuke Konishi wrote:
> > > Hi,
> > > On Fri, 5 Jun 2009 22:32:56 +0300, nezmer-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
> > > > Sorry for the late reply .
> > > > 
> > > > I tried to use deplock but I always get this :
> > > > SysRq : Show Locks Held
> > > > INFO: lockdep is turned off.
> > > > 
> > > > sysrq t works . I hope the attached file will be helpful .
> > > 
> > > Thanks for the log!
> > > 
> > > According to you log, the performance problem seems to be caused
> > > by a wait function in segment constructor of nilfs.
> > > 
> > > If you have a chance, please try the following coupled patch which
> > > comes from two patches queued for 2.6.31.  The upper half of the patch
> > > greatly improves read performance, and the lower part may have effect
> > > on the write performance.
> > > 
> > > Regards,
> > > Ryusuke Konishi
> > 
> > Unfortunately , the patches didn't help . I tried another flash disk. I
> > tried another archive (.tar.gz this time)  and the problem is still
> > there .
> > 
> > Is It possible the problem is related to snapshotting ? (the pauses
> > happen around 7 times in 40 seconds)
> 
> I think the pause is related to garbage collection.  What will happen
> if you mount the partition with -i option ?
> 
>    # mount -t nilfs2 -i /dev/xxx /mnt/media
> 
> This option skips invoking the garbage collector (cleanerd).

Oops, your log shows the cleanerd is sleeping.

So, the 5 seconds interval likely comes from regular writeback by the
segment constructor thread.

Could you tell me the product name of your USB flash ?

I will try expansion of a rar file against my pendrive (cruzer)

Thanks,
Ryusuke Konishi

> If it raises throughput, you can adjust by slowing down cleanerd by
> rewriting /etc/nilfs_cleanerd.conf (a HUP signal must be sent to the
> cleanerd to reflect the change):
> 
>    # The maximum number of segments to be cleaned at a time.
>  - nsegments_per_clean     2
>  + nsegments_per_clean     1
> 
>    # Cleaning interval in seconds
>  - cleaning interval       5
>  + cleaning interval       10
> 
> 
> Thanks,
> Ryusuke Konishi
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