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Subject: Re: [Xen-devel] [PATCH] x86/xen: Use DIV_ROUND_UP
To: Amitoj Kaur Chawla <amitoj1606@gmail.com>, <boris.ostrovsky@oracle.com>,
        <david.vrabel@citrix.com>, <jgross@suse.com>, <tglx@linutronix.de>,
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        <xen-devel@lists.xenproject.org>, <linux-kernel@vger.kernel.org>
References: <20160629150038.GA13956@amitoj-Inspiron-3542>
CC: <julia.lawall@lip6.fr>
From: David Vrabel <david.vrabel@citrix.com>
Message-ID: <5773ECFC.3000407@citrix.com>
Date: Wed, 29 Jun 2016 16:45:00 +0100
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On 29/06/16 16:00, Amitoj Kaur Chawla wrote:
> The kernel.h macro DIV_ROUND_UP performs the computation
> (((n) + (d) - 1) /(d)) but is perhaps more readable.
> 
> The Coccinelle script used to make this change is as follows:
> @haskernel@
> @@
> 
> #include <linux/kernel.h>
> 
> @depends on haskernel@
> expression n,d;
> @@
> 
> (
> - (n + d - 1) / d
> + DIV_ROUND_UP(n,d)
> |
> - (n + (d - 1)) / d
> + DIV_ROUND_UP(n,d)
> )

Applied to for-linus-4.8, thanks.

PFN_UP/DOWN() are for converting addresses to PFNs.  DIV_ROUND_UP() is
clearer when converting sizes to numbers of pages (as demonstrated by
the incorrect suggestion to use PFN_DOWN()).

David