Message-ID: <54573B72.1060600@nod.at>
Date: Mon, 03 Nov 2014 09:23:14 +0100
From: Richard Weinberger <richard@nod.at>
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To: Christoph Hellwig <hch@infradead.org>
CC: axboe@fb.com, dedekind1@gmail.com, ezequiel.garcia@free-electrons.com,
        dwmw2@infradead.org, computersforpeace@gmail.com,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] UBI: Block: Add blk-mq support
References: <1414933255-3795-1-git-send-email-richard@nod.at> <20141103081821.GA5261@infradead.org>
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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.

> Also I'll send a patch ASAP that allows drivers to ensure their
> ->queue_rq is always called from a driver-specific workqueue, which
> should simplify the bui block driver a lot.

Sounds great!

Thanks,
//richard
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