From: Matthew Wilcox <willy@infradead.org>
To: Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
Russell King <linux@armlinux.org.uk>,
Mike Rapoport <rppt@linux.ibm.com>, Rob Herring <robh@kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Doug Berger <opendmb@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arch : arm : add a criteria for pfn_valid
Date: Fri, 16 Aug 2019 20:34:42 -0700 [thread overview]
Message-ID: <20190817033441.GD18474@bombadil.infradead.org> (raw)
In-Reply-To: <1566010813-27219-1-git-send-email-huangzhaoyang@gmail.com>
On Sat, Aug 17, 2019 at 11:00:13AM +0800, Zhaoyang Huang wrote:
> #ifdef CONFIG_HAVE_ARCH_PFN_VALID
> int pfn_valid(unsigned long pfn)
> {
> - return memblock_is_map_memory(__pfn_to_phys(pfn));
> + return (pfn > max_pfn) ?
> + false : memblock_is_map_memory(__pfn_to_phys(pfn));
> }
This is a really awkward way to use the ternary operator. It's easier to
read if you just:
+ if (pfn > max_pfn)
+ return 0;
return memblock_is_map_memory(__pfn_to_phys(pfn));
(if you really wanted to be clever ... er, obscure, you'd've written:
return (pfn <= max_pfn) && memblock_is_map_memory(__pfn_to_phys(pfn));
... but don't do that)
Also, why is this diverged between arm and arm64?
next prev parent reply other threads:[~2019-08-17 3:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-17 3:00 Zhaoyang Huang
2019-08-17 3:34 ` Matthew Wilcox [this message]
2019-08-17 9:00 ` Mike Rapoport
2019-08-17 9:14 ` Zhaoyang Huang
2019-08-17 18:32 ` Russell King - ARM Linux admin
2019-08-18 7:46 ` Zhaoyang Huang
2019-08-18 8:20 ` Mike Rapoport
2019-08-18 10:15 ` Russell King - ARM Linux admin
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