From: Jens Axboe <axboe@kernel.dk>
To: Geert Uytterhoeven <geert@linux-m68k.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] block: Do not call sector_div() with a 64-bit divisor
Date: Mon, 04 Nov 2013 15:29:43 -0700 [thread overview]
Message-ID: <52781FD7.9050507@kernel.dk> (raw)
In-Reply-To: <1383570006-4605-1-git-send-email-geert@linux-m68k.org>
On 11/04/2013 06:00 AM, Geert Uytterhoeven wrote:
> do_div() (called by sector_div() if CONFIG_LBDAF=y) is meant for divisions
> of 64-bit number by 32-bit numbers. Passing 64-bit divisor types caused
> issues in the past on 32-bit platforms, cfr. commit
> ea077b1b96e073eac5c3c5590529e964767fc5f7 ("m68k: Truncate base in
> do_div()").
>
> As queue_limits.max_discard_sectors and .discard_granularity are unsigned
> int, max_discard_sectors and granularity should be unsigned int.
> As bdev_discard_alignment() returns int, alignment should be int.
> Now 2 calls to sector_div() can be replaced by 32-bit arithmetic:
> - The 64-bit modulo operation can become a 32-bit modulo operation,
> - The 64-bit division and multiplication can be replaced by a 32-bit
> modulo operation and a subtraction.
Thanks Geert, applied.
--
Jens Axboe
prev parent reply other threads:[~2013-11-04 22:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-04 13:00 [PATCH] block: Do not call sector_div() with a 64-bit divisor Geert Uytterhoeven
2013-11-04 22:29 ` Jens Axboe [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=52781FD7.9050507@kernel.dk \
--to=axboe@kernel.dk \
--cc=akpm@linux-foundation.org \
--cc=geert@linux-m68k.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.