From: Daniel Jacobowitz <dan@debian.org>
To: "Richard B. Johnson" <root@chaos.analogic.com>
Cc: Linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: atomic_t (24 bits???)
Date: Tue, 25 Feb 2003 14:17:11 -0500 [thread overview]
Message-ID: <20030225191711.GA25331@nevyn.them.org> (raw)
In-Reply-To: <Pine.LNX.3.95.1030225140554.20186A-100000@chaos>
On Tue, Feb 25, 2003 at 02:11:11PM -0500, Richard B. Johnson wrote:
>
> In ../linux/include/asm/atomic.h, for versions 2.4.18 and
> above as far as I've checked, there are repeated warnings
> "Note that the guaranteed useful range of an atomic_t is
> only 24 bits."
>
> I fail to see any reason why as atomic_t is typdefed to a
> volatile int which, on ix86 seems to be 32 bits.
>
> Does anybody know if this is just some old comments from a
> previous atomic_t type of, perhaps, char[3]?
There are other platforms where you can't reliably use the whole word.
Some ARM atomic_t implementations are like this, although I don't know
if the one in the kernel is.
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
next prev parent reply other threads:[~2003-02-25 19:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-02-25 19:11 atomic_t (24 bits???) Richard B. Johnson
2003-02-25 19:14 ` Roman Zippel
2003-02-25 19:31 ` Richard B. Johnson
2003-02-25 19:17 ` Daniel Jacobowitz [this message]
2003-02-25 19:31 ` Richard B. Johnson
2003-02-25 21:57 ` Russell King
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=20030225191711.GA25331@nevyn.them.org \
--to=dan@debian.org \
--cc=linux-kernel@vger.kernel.org \
--cc=root@chaos.analogic.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.