[CC'ing Omar as Kyber is mentioned] On 12.11.21 г. 20:06, Chris Murphy wrote: > On Fri, Nov 12, 2021 at 1:55 AM Nikolay Borisov <nborisov@xxxxxxxx> wrote: >> >> >> >> On 11.11.21 г. 22:57, Chris Murphy wrote: >>> On Thu, Nov 11, 2021 at 3:24 PM Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: >>>> >>>> Soon after logging in and launching some apps, I get a hang. Although >>>> there's lots of btrfs stuff in the call traces, I think we're stuck in >>>> writeback so everything else just piles up and it all hangs >>>> indefinitely. >>>> >>>> Happening since at least >>>> 5.16.0-0.rc0.20211109gitd2f38a3c6507.9.fc36.x86_64 and is still happening with >>>> 5.16.0-0.rc0.20211111gitdebe436e77c7.11.fc36.x86_64 >>>> >>>> Full dmesg including sysrq+w when the journal becomes unresponsive and >>>> then a bunch of block tasks > 120s roll in on their own. >>>> >>>> https://bugzilla-attachments.redhat.com/attachment.cgi?id=1841283 >>> >> >> >> The btrfs traces in this one doesn't look interesting, what's >> interesting is you have a bunch of tasks, including btrfs transaction >> commit which are stuck waiting to get a tag from the underlying block >> device - blk_mq_get_tag function. This indicates something's going on >> with the underlying block device. > > Well the hang doesn't ever happen with 5.14.x or 5.15.x kernels, only > the misc-next (Fedora rc0) kernels. And also I just discovered that > it's not happening (or not as quickly) with IO scheduler none. I've > been using kyber and when I switch back to it, the hang happens almost > immediately. Well I see a bunch of WARN_ONs being triggered, so is it possible that this is some issue which is going to be fixed in some future RC ? Omar what steps should be taken to try and debug this from the Kyber side of things? > > > >
