Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain;
        charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\))
Subject: Re: Bisected GFP in bfq_bfqq_expire on v5.1-rc1
From:   Paolo Valente <paolo.valente@linaro.org>
In-Reply-To: <20190401122233.3e861312@fire.localdomain>
Date:   Mon, 1 Apr 2019 12:35:11 +0200
Cc:     Jens Axboe <axboe@kernel.dk>,
        linux-block <linux-block@vger.kernel.org>,
        linux-kernel@vger.kernel.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <EBC090F1-72C0-4794-91CC-37F9A2A1DEFB@linaro.org>
References: <20190329160227.7d55c8dd@fire.localdomain>
 <0e203a26-b941-cef4-dff1-013999d4b041@kernel.dk>
 <626EAE58-63C1-4ABA-9040-9D9A61F74A0D@linaro.org>
 <20190401115509.76310e03@fire.localdomain>
 <84B0CA50-0ED8-4171-8007-19EA43951735@linaro.org>
 <20190401122233.3e861312@fire.localdomain>
To:     Dmitrii Tcvetkov <demfloro@demfloro.ru>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> Il giorno 1 apr 2019, alle ore 11:22, Dmitrii Tcvetkov =
<demfloro@demfloro.ru> ha scritto:
>=20
> On Mon, 1 Apr 2019 11:01:27 +0200
> Paolo Valente <paolo.valente@linaro.org> wrote:
>> Ok, thank you. Could you please do a
>>=20
>> list *(bfq_bfqq_expire+0x1f3)
>>=20
>> for me?
>>=20
>> Thanks,
>> Paolo
>>=20
>>>=20
>>> <gpf.txt><gpf-w-bfq-group-iosched.txt><config.txt>
>=20
> Reading symbols from vmlinux...done.
> (gdb) list *(bfq_bfqq_expire+0x1f3)
> 0xffffffff813d02c3 is in bfq_bfqq_expire (block/bfq-iosched.c:3390).
> 3385             * even in case bfqq and thus parent entities go on =
receiving=20
> 3386             * service with the same budget.
> 3387             */
> 3388            entity =3D entity->parent;
> 3389            for_each_entity(entity)
> 3390                    entity->service =3D 0;
> 3391    }
> 3392
> 3393    /*
> 3394     * Budget timeout is not implemented through a dedicated =
timer, but

Thank you very much.  Unfortunately this doesn't ring any bell.  I'm
trying to reproduce the failure.  It will probably take a little
time.  If I don't make it, I'll ask you to kindly retry after applying
some instrumentation patch.

Thanks,
Paolo=