From: Benjamin LaHaise <bcrl@redhat.com>
To: Andi Kleen <ak@suse.de>
Cc: Dean Nelson <dcn@sgi.com>, linux-kernel@vger.kernel.org
Subject: Re: atomic64_t proposal
Date: Tue, 27 Aug 2002 16:54:17 -0400 [thread overview]
Message-ID: <20020827165417.C23980@redhat.com> (raw)
In-Reply-To: <p73sn102hvu.fsf@oldwotan.suse.de>; from ak@suse.de on Tue, Aug 27, 2002 at 09:58:45PM +0200
On Tue, Aug 27, 2002 at 09:58:45PM +0200, Andi Kleen wrote:
> Is it supposed to only work on 64bit or do you plan to supply it for 32
> bit too? If no, I don't see how drivers etc. should ever use it. linux
> is supposed to have a common kernel api.
> If yes, the implementation on 32bit could be a problem. e.g. some
> archs need space in there for spinlocks, so it would be needed to limit
> the usable range.
There are a couple of options for implementations to use that don't
require space for a spinlock: a hash table of spinlocks can be used
to protect the data (parisc uses this technique). Andrea's lockless
reader locks could be useful in this case. Most x86es can use cmpxchg8,
and the 64 bit machines are already set. I suspect it would be a useful
addition to the kernel APIs.
-ben
--
"You will be reincarnated as a toad; and you will be much happier."
next prev parent reply other threads:[~2002-08-27 20:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200208271937.OAA78345@cyan.americas.sgi.com.suse.lists.linux.kernel>
2002-08-27 19:58 ` atomic64_t proposal Andi Kleen
2002-08-27 20:29 ` David S. Miller
2002-08-27 20:54 ` Benjamin LaHaise [this message]
2002-08-29 17:15 ` Dean Nelson
2002-08-28 15:45 Robin Holt
2002-08-28 21:39 ` H. Peter Anvin
-- strict thread matches above, loose matches on Subject: below --
2002-08-27 19:37 Dean Nelson
2002-08-27 20:02 ` Andreas Schwab
2002-08-28 14:59 ` Dean Nelson
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=20020827165417.C23980@redhat.com \
--to=bcrl@redhat.com \
--cc=ak@suse.de \
--cc=dcn@sgi.com \
--cc=linux-kernel@vger.kernel.org \
/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