From: Peter Zijlstra <peterz@infradead.org>
To: Matthew Wilcox <matthew@wil.cx>
Cc: Justin Chen <jchen@hpdst41.cup.hp.com>,
linux-arch@vger.kernel.org, bjorn.helgaas@hp.com,
justin.chen@hp.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/15] bitops: Change bitmap index from int to unsigned long
Date: Wed, 25 Feb 2009 16:46:00 +0100 [thread overview]
Message-ID: <1235576760.4645.3535.camel@laptop> (raw)
In-Reply-To: <20090225153757.GP16891@parisc-linux.org>
On Wed, 2009-02-25 at 08:37 -0700, Matthew Wilcox wrote:
> On Wed, Feb 25, 2009 at 07:54:48AM +0100, Peter Zijlstra wrote:
> > unsigned int wasn't large enough?
>
> Adding one more bit only doubles the maximum size. That buys us, what,
> another eighteen months until we have to change it again? Unsigned long
> seems most sensible to me. Unsigned long long probably isn't worth
> doing -- you'd have to be using one eighth of your address space on a
> single bitmap.
Are you serious? Bitmaps of length 4G-bit (512M-byte) are way past the
sanely allocatable size anyway.
The complaint was that the signed thingy resulted in out of bounds
pointers (apparently unsigned doesn't?)
next prev parent reply other threads:[~2009-02-25 15:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-25 4:41 [PATCH 00/15] bitops: Change bitmap index from int to unsigned long Justin Chen
2009-02-25 6:54 ` Peter Zijlstra
2009-02-25 15:37 ` Matthew Wilcox
2009-02-25 15:46 ` Peter Zijlstra [this message]
2009-02-25 15:46 ` Peter Zijlstra
2009-02-25 15:53 ` Matthew Wilcox
2009-02-25 16:03 ` Peter Zijlstra
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=1235576760.4645.3535.camel@laptop \
--to=peterz@infradead.org \
--cc=bjorn.helgaas@hp.com \
--cc=jchen@hpdst41.cup.hp.com \
--cc=justin.chen@hp.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=matthew@wil.cx \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox