W dniu 06.09.2016 o 04:24, Kent Overstreet pisze:
Hi!

On Sun, Sep 04, 2016 at 08:21:17PM +0200, Marcin wrote:

quoted

W dniu 2016-09-04 02:17, Kent Overstreet napisał(a):

Hi!

quoted

On Sat, Sep 03, 2016 at 11:29:49PM +0200, Marcin wrote:

quoted

Hi!
Kernel at commit c820493652e830dc050e1418301e1bdec5691a1e

I createt to devices, fast has size
# blockdev --getsz /dev/sde1
20971520
and slower device:
# blockdev --getsz /dev/sdd1
2930209551

I was copying files from one disk to bcache, after some time I got:
 BUG: soft lockup - CPU#0 stuck for 22s! [bch_copygc_read:5328]

Thanks for the report - can you run addr2line with your vmlinux file,
and the
RIP?

addr2line -i -e vmlinux ffffffffc028795b

It returned:
??:0

Probably due to I'm using bcache as module.
<long story>
As I mentioned before I wasn't sure which branch I used to test.

In case I didn't mention before - bcache-dev. This bug in the bcache-encryption
branch is a bit disconcerting though since my tests never hit it, but don't
worry about it - I'll chase it down.

I think that bug "BUG: soft lockup" is due to problem with bucket size.
I saw many random, different bugs when second tiered device had bucket
size equal to 768.

quoted

Please look at line with "bucket size":
bucket_size:            768
If bucket size is higher than (probably) 512 then I can't mount simple
(without tiering) bcachefs filesystem. If I use such big device in tiered
bcachefs I'm expieriencing random problems with stability of box.
I think that bug in mail's subject is only random symptom of problem when
device is formated with bucket size >512.
What is going inside kernel in this case, is overwittem memory of other
processes?

Whoops - that one is a bug in bcache-tools, non power of two bucket sizes aren't
supported (might be someday, but aren't currently). I just pushed a fix for that
to bcache-tools.

One mor thing, when I tested tiering with one device formated with
unsupported bucket sizethis command worked:
# mount /dev/sde1:/dev/sdd1 /mnt/test
but this one didn't:
# mount /dev/sdd1:/dev/sde1 /mnt/test

so:
<low priority wish>
it could be good to check if on disk format of every device is correct
and supported.

Thank you,
Marcin