From: David Howells <dhowells@redhat.com>
To: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
ARM Linux Mailing List <linux-arm-kernel@lists.arm.linux.org.uk>,
Dan Williams <dan.j.williams@intel.com>,
linux-kernel@vger.kernel.org, torvalds@osdl.org,
dhowells@redhat.com
Subject: Re: I/O memory barriers vs SMP memory barriers
Date: Mon, 26 Mar 2007 11:04:11 +0100 [thread overview]
Message-ID: <3971.1174903451@redhat.com> (raw)
In-Reply-To: <20070325213843.GE22126@xi.wantstofly.org>
Lennert Buytenhek <buytenh@wantstofly.org> wrote:
> Does everybody agree on these semantics, though? At least David seems
> to think that mb/rmb/wmb aren't required to order normal memory accesses
> against each other..
Ummm... I've just realised that your statement here is ambiguous. When you
say "aren't required to", do you mean "aren't necessary to" or do you mean
"don't have to"? Isn't English a fun language?
Anyway, what I meant is that mb() and co. as they stand _must_ do everything
smp_mb() and co do respectively, _in_ _addition_ to other side effects.
mb() implies smp_mb()
rmb() implies smp_rmb()
wmb() implies smp_wmb()
...
David
prev parent reply other threads:[~2007-03-26 10:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <e9c3a7c20703021312y5f7aa228i5d1c84a8e9ea5676@mail.gmail.com>
[not found] ` <20070303111427.GB16944@xi.wantstofly.org>
[not found] ` <20070303113305.GB10515@flint.arm.linux.org.uk>
[not found] ` <20070321221134.GA22497@xi.wantstofly.org>
[not found] ` <tnxlkhpgslz.fsf@arm.com>
[not found] ` <20070323111350.GD3980@xi.wantstofly.org>
2007-03-23 13:43 ` I/O memory barriers vs SMP memory barriers David Howells
2007-03-23 15:08 ` Lennert Buytenhek
2007-03-24 20:16 ` Benjamin Herrenschmidt
2007-03-26 10:07 ` David Howells
2007-03-25 21:15 ` Paul E. McKenney
2007-03-25 21:38 ` Lennert Buytenhek
2007-03-26 3:24 ` Paul E. McKenney
2007-03-26 8:46 ` Lennert Buytenhek
2007-03-26 20:07 ` Paul E. McKenney
2007-03-28 18:36 ` Lennert Buytenhek
2007-03-26 10:04 ` David Howells [this message]
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=3971.1174903451@redhat.com \
--to=dhowells@redhat.com \
--cc=buytenh@wantstofly.org \
--cc=catalin.marinas@arm.com \
--cc=dan.j.williams@intel.com \
--cc=linux-arm-kernel@lists.arm.linux.org.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=torvalds@osdl.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 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.