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Date:   Tue, 4 Feb 2020 07:13:53 -0600
From:   Segher Boessenkool <segher@kernel.crashing.org>
To:     David Hildenbrand <david@redhat.com>
Cc:     Oscar Salvador <osalvador@suse.de>, linux-s390@vger.kernel.org,
        Michal Hocko <mhocko@suse.com>, linux-ia64@vger.kernel.org,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        linux-sh@vger.kernel.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Wei Yang <richardw.yang@linux.intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linuxppc-dev@lists.ozlabs.org,
        Dan Williams <dan.j.williams@intel.com>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
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On Tue, Feb 04, 2020 at 01:41:06PM +0100, David Hildenbrand wrote:
> On 04.02.20 10:46, Oscar Salvador wrote:
> > I have to confess that it took me while to wrap around my head
> > with the new min() change, but looks ok:
> 
> It's a pattern commonly used in compilers and emulators to calculate the
> number of bytes to the next block/alignment. (we're missing a macro
> (like we have ALIGN_UP/IS_ALIGNED) for that - but it's hard to come up
> with a good name (e.g., SIZE_TO_NEXT_ALIGN) .

You can just write the easy to understand

  ...  ALIGN_UP(x) - x  ...

which is better *without* having a separate name.  Does that not
generate good machine code for you?


Segher