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Message-ID: <1517998516.6606.1.camel@gmx.de>
Subject: Re: [PATCH BUGFIX 1/1] block, bfq: add requeue-request hook
From:   Mike Galbraith <efault@gmx.de>
To:     Paolo Valente <paolo.valente@linaro.org>
Cc:     Oleksandr Natalenko <oleksandr@natalenko.name>,
        Jens Axboe <axboe@kernel.dk>,
        linux-block <linux-block@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Mark Brown <broonie@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        'Paolo Valente' via bfq-iosched 
        <bfq-iosched@googlegroups.com>,
        Alban Browaeys <alban.browaeys@gmail.com>,
        Ming Lei <ming.lei@redhat.com>, Ivan Kozik <ivan@ludios.org>,
        SERENA ZIVIANI <169364@studenti.unimore.it>,
        Serena Ziviani <ziviani.serena@gmail.com>,
        Holger =?ISO-8859-1?Q?Hoffst=E4tte?= 
        <holger@applied-asynchrony.com>
Date:   Wed, 07 Feb 2018 11:15:16 +0100
In-Reply-To: <FBF6DCBB-B0F5-446B-8FD1-106E2538A9C1@linaro.org>
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On Wed, 2018-02-07 at 10:45 +0100, Paolo Valente wrote:
> 
> > Il giorno 07 feb 2018, alle ore 10:23, Mike Galbraith <efault@gmx.de> ha scritto:
> > 
> > On Wed, 2018-02-07 at 10:08 +0100, Paolo Valente wrote:
> >> 
> >> The first piece of information I need is whether this failure happens
> >> even without "BFQ hierarchical scheduling support".
> > 
> > I presume you mean BFQ_GROUP_IOSCHED, which I do not have enabled.
> > 
> 
> Great (so to speak), this saves us one step.
> 
> So, here's my next request for help: please apply the attached patch
> (compressed to preserve it from my email client) and retry. It adds
> several anomaly checks. I hope I have not added any false-positive
> check.

kernel BUG at block/bfq-iosched.c:4742!

4742         BUG_ON(!(rq->rq_flags & RQF_ELVPRIV));