Re: [fuse-devel] Horrible mmap write performance (kernel writeback issue?)

[Tejun Heo]

Hello,

On Mon, Mar 28, 2016 at 09:45:53PM +0200, Miklos Szeredi wrote:
> >> commit 947e9762a8ddefda38aa21e249e6a4fec215cd12
> >> Author: Tejun Heo <tj@xxxxxxxxxx>
> >> Date:   Fri May 22 18:23:32 2015 -0400
> >>
> >>     writeback: update wb_over_bg_thresh() to use wb_domain aware operations
> >
> 
> Tejun,
> 
> Any idea why this commit stalls fuse mmap writes?
> 
> Here's the start of the this thread:
> 
>   http://marc.info/?l=fuse-devel&m=145008058603261&w=2

Hmmm... cgroup writeback support shouldn't affect fuse at all as the
backing device doesn't enable cgroup support.  I probably made some
silly mistake.  Is there a simple reproducer I can play with?

Thanks.

-- 
tejun