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Subject: Re: [PATCH] UBI: Block: Add blk-mq support
From: Artem Bityutskiy <dedekind1@gmail.com>
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To: Richard Weinberger <richard@nod.at>
Date: Fri, 07 Nov 2014 11:46:36 +0200
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Cc: axboe@fb.com, linux-kernel@vger.kernel.org,
 Christoph Hellwig <hch@infradead.org>, linux-mtd@lists.infradead.org,
 ezequiel.garcia@free-electrons.com, computersforpeace@gmail.com,
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On Mon, 2014-11-03 at 09:23 +0100, Richard Weinberger wrote:
> Am 03.11.2014 um 09:18 schrieb Christoph Hellwig:
> > On Sun, Nov 02, 2014 at 02:00:55PM +0100, Richard Weinberger wrote:
> >> +#define UBIBLOCK_SG_COUNT 64
> > 
> > 
> > Can you document why you choose this number? The default nr_request
> > for the old code would be 128.
> 
> Is 64 a problem? Beside of the fact that I forgot to set blk_queue_max_segments().
> I used this number because 128 seemed a bit high and my goal was to
> keep the memory footprint small.
> This is also why I've set tag_set.queue_depth to 64.

The request was to document, so lets' document the choice.

Artem.