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Date:   Sat, 17 Jul 2021 17:35:32 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Oleksandr Natalenko <oleksandr@natalenko.name>
Cc:     linux-kernel@vger.kernel.org, Jens Axboe <axboe@fb.com>,
        Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        linux-nvme@lists.infradead.org,
        David Jeffery <djeffery@redhat.com>,
        Laurence Oberman <loberman@redhat.com>,
        Paolo Valente <paolo.valente@linaro.org>,
        Jan Kara <jack@suse.cz>, Sasha Levin <sashal@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Keith Busch <kbusch@kernel.org>
Subject: Re: New warning in nvme_setup_discard
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References: <4729812.CpyZKHjjVO@natalenko.name>
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 <1687461.6WkTYu5mUM@natalenko.name>
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On Fri, Jul 16, 2021 at 02:56:22PM +0200, Oleksandr Natalenko wrote:
> On pátek 16. července 2021 12:41:52 CEST Ming Lei wrote:
> > > Do I understand correctly that this will be something like:
> > > 
> > > Fixes: 2705dfb209 ("block: fix discard request merge")
> > > 
> > > ?
> > > 
> > > Because as the bisection progresses, I've bumped into this commit only.
> > > Without it the issue is not reproducible, at least so far.
> > 
> > It could be.
> > 
> > So can you just test v5.14-rc1?
> 
> Doing it right now, but I've got another issue. Why BFQ is not listed here:
> 
> ```
> /sys/class/block/nvme0n1/queue/scheduler:[mq-deadline] kyber none
> /sys/class/block/nvme1n1/queue/scheduler:[mq-deadline] kyber none
> ```

Maybe you need to check if the build is OK, I can't reproduce it in my
VM, and BFQ is still builtin:

[root@ktest-01 ~]# uname -a
Linux ktest-01 5.14.0-rc1+ #52 SMP Fri Jul 16 18:56:36 CST 2021 x86_64 x86_64 x86_64 GNU/Linux
[root@ktest-01 ~]# cat /sys/block/nvme0n1/queue/scheduler
[none] mq-deadline kyber bfq

> 
> ?
> 
> It is a built-in, FWIW:
> 
> ```
> $ modinfo bfq
> name:           bfq
> filename:       (builtin)
> description:    MQ Budget Fair Queueing I/O Scheduler
> license:        GPL
> file:           block/bfq
> author:         Paolo Valente
> alias:          bfq-iosched
> ```
> 
> So far the issue is not reproducible with your patch + 5.13.2 as well as 5.14-
> rc1 (but I don't have BFQ either with v5.14-rc1).

You have to verify it with BFQ applied, :-)


Thanks, 
Ming