[Bug 215679] New: NVMe/writeback wb_workfn/blocked for more than 30 seconds

[Keith Busch]

On Sun, Mar 13, 2022 at 08:13:53PM +0000, bugzilla-daemon at kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=215679
> 
>             Bug ID: 215679
>            Summary: NVMe/writeback wb_workfn/blocked for more than 30
>                     seconds
>            Product: IO/Storage
>            Version: 2.5
>     Kernel Version: 5.17.0-rc7
>           Hardware: x86-64
>                 OS: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: high
>           Priority: P1
>          Component: NVMe
>           Assignee: io_nvme at kernel-bugs.kernel.org
>           Reporter: imre.deak at intel.com
>         Regression: No
> 
> Created attachment 300564
>   --> https://bugzilla.kernel.org/attachment.cgi?id=300564&action=edit
> dmesg log after suspend resume, io stuck
> 
> After system suspend/resume filesystem IO will stall, producing a 'kworker
> blocked for more than x sec" in dmesg, recovering after a long delay. See the
> attached dmesg-suspend-resume-nvme-stuck.txt. I also noticed the same issue
> happening right after booting or after runtime suspend transitions.
> 
> The same issue also happens on multiple SKL systems in the i915 team's CI farm,
> see:
> 
> https://gitlab.freedesktop.org/drm/intel/-/issues/4547
> 
> I bisected the problem to
> commit 4f5022453acd0f7b28012e20b7d048470f129894
> Author: Jens Axboe <axboe at kernel.dk>
> Date:   Mon Oct 18 08:45:39 2021 -0600
> 
>     nvme: wire up completion batching for the IRQ path
> 
> By reverting it on top of 5.17.0-rc7, I can't reproduce the problem. Attached  
> dmesg-suspend-resume-nvme-ok.txt with the revert, captured after a few
> suspend/resume.

Forwarding to linux-nvme for higher visibility.