From: Christoph Hellwig <hch@infradead.org>
To: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <dlemoal@kernel.org>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org
Subject: Re: [PATCH] null_blk: Always split BIOs to respect queue limits
Date: Fri, 26 Jan 2024 06:27:27 -0800 [thread overview]
Message-ID: <ZbPBTzxu-NWTU7Q8@infradead.org> (raw)
In-Reply-To: <84dce2ee-5d71-47a4-b114-3ca69b3c31fb@suse.de>
On Fri, Jan 26, 2024 at 08:05:21AM +0100, Hannes Reinecke wrote:
> > BIOs that need splitting. Doing so also fixes issues with zoned devices
> > as a large BIO may cross over a zone boundary, which breaks null_blk
> > zone emulation.
> >
> That feels so wrong. Why would we need to apply queue limits to a bio?
> (Yes, I know why. We still shouldn't be doing it.)
Because a driver that has limits should enforce them. Your hardware
doesn't suddenly use limits because you're using a bio based driver,
and null_blk shouldn't suddenly ignore the configured limits just
because you're using it in bio mode.
The patch looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
But yeah, I'd rather kill the bio mode. Jens, are you attached
to the bio mode? Otherwise I'll cook up a patch over the weekend.
prev parent reply other threads:[~2024-01-26 14:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 0:50 [PATCH] null_blk: Always split BIOs to respect queue limits Damien Le Moal
2024-01-26 7:05 ` Hannes Reinecke
2024-01-26 7:09 ` Damien Le Moal
2024-01-26 8:37 ` Chaitanya Kulkarni
2024-01-26 14:27 ` Christoph Hellwig [this message]
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