Comment # 101 on bug 1017461 from Edmund Nadolski

(In reply to Oliver Kurz from comment #99)
> To me it seems the issue is not really resolved even though I think the
> patches provided in the kernel by enadolski@suse.com should help. I guess
> one has to look at a more whole system level.

I am restoring the previous status as I am not clear of the justification to
re-open -- considering that the indicated patches evidently were not even run,
it is not shown that a problem still exists.

These patches have demonstrated a 50% improvement in btrfs backref performance,
so if further symptoms are observed there may well be other causes (not
necessarily even in the fs - as you mention the whole system would need to be
looked at).  In that case the best way forward is to please open a new BZ
including all relevant info so that it can be properly investigated (and
without potential obfuscation from the previous issue).