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From:   Oleksandr Natalenko <oleksandr@natalenko.name>
To:     Ming Lei <ming.lei@redhat.com>
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
Date:   Sat, 17 Jul 2021 14:19:59 +0200
Message-ID: <8988303.mDXGIdCtx8@natalenko.name>
In-Reply-To: <5053297.vgnLoh5Ws3@natalenko.name>
References: <4729812.CpyZKHjjVO@natalenko.name> <YPKkZJWsD84mmKuk@T590> <5053297.vgnLoh5Ws3@natalenko.name>
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On sobota 17. =C4=8Dervence 2021 14:11:05 CEST Oleksandr Natalenko wrote:
> On sobota 17. =C4=8Dervence 2021 11:35:32 CEST Ming Lei wrote:
> > Maybe you need to check if the build is OK, I can't reproduce it in my
> > VM, and BFQ is still builtin:
> >=20
> > [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
>=20
> I don't think this is an issue with the build=E2=80=A6 BTW, with `initcal=
l_debug`:
>=20
> ```
> [    0.902555] calling  bfq_init+0x0/0x8b @ 1
> [    0.903448] initcall bfq_init+0x0/0x8b returned -28 after 507 usecs
> ```
>=20
> -ENOSPC? Why? Also re-tested with the latest git tip, same result :(.

OK, one extra pr_info, and I see this:

```
[    0.871180] blkcg_policy_register: BLKCG_MAX_POLS too small
[    0.871612] blkcg_policy_register: -28
```

What does it mean please :)? The value seems to be hard-coded:

```
include/linux/blkdev.h
60:#define BLKCG_MAX_POLS               5
```

=2D-=20
Oleksandr Natalenko (post-factum)