Re: Bisected GFP in bfq_bfqq_expire on v5.1-rc1

Paolo Valente
2019-04-01T07:29:21Z

> Il giorno 29 mar 2019, alle ore 15:10, Jens Axboe <axboe@kernel.dk> ha scritto:
>
> On 3/29/19 7:02 AM, Dmitrii Tcvetkov wrote:
>> Hi,
>>
>> I got kernel panic since v5.1-rc1 when working with files on block
>> device with BFQ scheduler assigned. I didn't find trivial way to
>> reproduce the panic but "git checkout origin/linux-5.0.y"
>> on linux-stable-rc[1] git repo on btrfs filesystem reproduces the
>> problem 100% of the time on my bare-metal machine and in a VM.
>>
>> Bisect led me to commit 9dee8b3b057e1 (block, bfq: fix queue removal
>> from weights tree). After reverting this commit on top of current
>> mainline master(9936328b41ce) I can't reproduce the problem.
>>
>> dmesg with the panic and bisect log attached.
>>
>> [1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
>
> Paolo, can you please take a look at this?
>
>

Yep.

That you very much Dmitrii for also bisecting. I feel like this
failure may be caused by the typo fixed by this patch:
https://patchwork.kernel.org/patch/10877113/

Could you please give this fix a try?

Thanks,
Paolo

> --
> Jens Axboe