Re: ls & flush-btrfs-1 sit at 100% sys

[Josef Bacik <josef@redhat.com>]

On Fri, Nov 19, 2010 at 09:32:46AM -0500, Chris Mason wrote:
> Excerpts from Brian Sullivan's message of 2010-11-18 13:30:51 -0500:
> > Yep actually, with noatime,nodiratime ls is fine.  I didn't try ro but
> > I assume that'll work too.  So with noatime,nodiratime I can go around
> > in tree and ls works.  If I try to touch a new file, touch doesn't
> > return.  If I then ls in that same folder ls doesn't return either.
> > So yeah seems like soon as something has to write.
> > 
> > Also after I run touch, it doesn't return, I look at top, nothing is
> > spinning, everything is at 0% usage.  After a minute or so then touch
> > and flush-btrfs-1 jump to 50%sys each and sit there.
> 
> So, based on this trace we're banging on the delalloc flushing to free
> up room.
> 
> I just wanted to confirm, you're seeing this with 2.6.37-rc?  I thought
> I had fixed up this delalloc hammering.
> 

Also can you run with this patch

http://www.spinics.net/lists/linux-btrfs/msg06890.html

its a crap bug which will make us look like we're out of space when we arent and
we'll flush alot more.  Thanks,

Josef