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Date:   Tue, 21 Jul 2020 07:00:47 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Richard Weinberger <richard.weinberger@gmail.com>
Cc:     Artem Bityutskiy <dedekind1@gmail.com>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        linux-raid@vger.kernel.org, Hans de Goede <hdegoede@redhat.com>,
        Richard Weinberger <richard@nod.at>,
        LKML <linux-kernel@vger.kernel.org>, linux-block@vger.kernel.org,
        Song Liu <song@kernel.org>,
        device-mapper development <dm-devel@redhat.com>,
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        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
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        drbd-dev@lists.linbit.com
Subject: Re: [PATCH 04/14] bdi: initialize ->ra_pages in bdi_init
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References: <20200720075148.172156-1-hch@lst.de> <20200720075148.172156-5-hch@lst.de> <CAFLxGvxNHGEOrj6nKTtDeiU+Rx4xv_6asjSQYcFWXhk5m=1cBA@mail.gmail.com> <20200720120734.GA29061@lst.de> <2827a5dbd94bc5c2c1706a6074d9a9a32a590feb.camel@gmail.com> <CAFLxGvyxtYnJ5UdD18uNA97zQaDB8-Wv8MHQn2g9GYD74v7cTg@mail.gmail.com>
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On Mon, Jul 20, 2020 at 11:27:57PM +0200, Richard Weinberger wrote:
> On Mon, Jul 20, 2020 at 2:37 PM Artem Bityutskiy <dedekind1@gmail.com> wrote:
> >
> > On Mon, 2020-07-20 at 14:07 +0200, Christoph Hellwig wrote:
> > > What about jffs2 and blk2mtd raw block devices?
> 
> I don't worry much about blk2mtd.
> 
> > If my memory serves me correctly JFFS2 did not mind readahead.
> 
> This covers my knowledge too.
> I fear enabling readahead on JFFS2 will cause performance issues, this
> filesystem
> is mostly used on small and slow NOR devices.

I'm going to wait for Hans for feedback on vboxsf, but in doubt I'll
ust add a prep patch or fold for this one to explicit set ra_pages to 0
with a comment then.