linux-kernel - Re: [PATCH] block: iolatency: avoid 64-bit division

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Date:   Tue, 10 Jul 2018 14:16:07 -0400
From:   Josef Bacik <josef@...icpanda.com>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Jens Axboe <axboe@...nel.dk>, Tejun Heo <tj@...nel.org>,
        Josef Bacik <jbacik@...com>, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] block: iolatency: avoid 64-bit division

On Tue, Jul 10, 2018 at 05:21:34PM +0200, Arnd Bergmann wrote:
> On 32-bit architectures, dividing a 64-bit number needs to use the
> do_div() function or something like it to avoid a link failure:
> 
> block/blk-iolatency.o: In function `iolatency_prfill_limit':
> blk-iolatency.c:(.text+0x8cc): undefined reference to `__aeabi_uldivmod'
> 
> Using div_u64() gives us the best output and avoids the need for an
> explicit cast.
> 
> Fixes: d70675121546 ("block: introduce blk-iolatency io controller")
> Signed-off-by: Arnd Bergmann <arnd@...db.de>

Oops sorry Arnd,

Reviewed-by: Josef Bacik <josef@...icpanda.com>