Messages in this thread | | | Date | Mon, 28 Mar 2016 21:45:53 +0200 | Subject | Re: [fuse-devel] Horrible mmap write performance (kernel writeback issue?) | From | Miklos Szeredi <> |
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On Sat, Mar 26, 2016 at 10:42 PM, Jakob Unterwurzacher <jakobunt@gmail.com> wrote: > On 16.03.2016 10:44, Miklos Szeredi wrote: >> On Tue, Mar 15, 2016 at 8:55 AM, Jakob Unterwurzacher >> <jakobunt@gmail.com> wrote: >>> Just for anybody finding this thread: This still happens in v4.4, it >>> just took longer to trigger. >>> >>> I have posted more details to linux-kernel (copy-pasted below), >>> http://thread.gmane.org/gmane.linux.kernel/2132944 >> >> Okay, so you can reproduce this relatively quickly. Can you try "git >> bisect" to find exactly which commit is responsible? >> >> Thanks, >> Miklos > > That took a while, but it looks like it got it: > >> commit 947e9762a8ddefda38aa21e249e6a4fec215cd12 >> Author: Tejun Heo <tj@kernel.org> >> 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
Thanks, Miklos
> Note that this commens seems to only activate changes that happened in the > commit before, aa661bb: > >> commit aa661bbe1e61ce80ca4ae98804f673ede94b0827 >> Author: Tejun Heo <tj@kernel.org> >> Date: Fri May 22 18:23:31 2015 -0400 >> >> writeback: move over_bground_thresh() to mm/page-writeback.c > > > Anyway, I can reliably reboot between aa661bb and 947e976 and always get the > same results: > > aa661bb passes > 947e976 fails > > I you want to reproduce, clone https://github.com/rfjakob/mmapwrite.git and > run ./encfs-test.sh (needs encfs installed). On the bad kernel, it will hang > within a few seconds. > > Thanks, > Jakob
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