From: Matthew Wilcox <matthew@wil.cx>
To: Andi Kleen <andi@firstfloor.org>
Cc: Namhyung Kim <namhyung@gmail.com>, Arnd Bergmann <arnd@arndb.de>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] introduce ptr_diff()
Date: Thu, 19 Aug 2010 06:40:17 -0600 [thread overview]
Message-ID: <20100819124017.GI12892@parisc-linux.org> (raw)
In-Reply-To: <87aaoiu6z6.fsf@basil.nowhere.org>
On Thu, Aug 19, 2010 at 02:23:09PM +0200, Andi Kleen wrote:
> IMHO it would be better to simply disable the warning in sparse instead
> of uglying the code just to work around sparse bogosity. It doesnt' seem
> to make much sense. A subtraction followed by a shift is not expensive.
What makes you think it's a shift? struct page isn't necessarily a
power of two in size. The original poster said "allyesconfig" which is
going to add in KMEMCHECK and WANT_PAGE_DEBUG_FLAGS. I think that makes
it 76 bytes on x86-32, so sparse is right to warn.
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next prev parent reply other threads:[~2010-08-19 12:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-19 11:37 [RFC][PATCH] introduce ptr_diff() Namhyung Kim
2010-08-19 11:57 ` Bernd Petrovitsch
2010-08-19 12:03 ` David Howells
2010-08-19 16:18 ` Måns Rullgård
2010-08-19 12:23 ` Andi Kleen
2010-08-19 12:40 ` Matthew Wilcox [this message]
2010-08-19 12:58 ` Andi Kleen
2010-08-19 12:48 ` Bernd Petrovitsch
2010-08-19 12:59 ` Andi Kleen
2010-08-19 13:05 ` Bernd Petrovitsch
2010-08-19 13:39 ` Andi Kleen
2010-08-20 12:12 ` Al Viro
2010-08-19 15:53 ` Namhyung Kim
2010-08-19 16:04 ` Bernd Petrovitsch
2010-08-19 16:12 ` Namhyung Kim
2010-08-20 12:07 ` Al Viro
2010-08-20 12:49 ` Matthew Wilcox
2010-08-20 12:57 ` Andi Kleen
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