All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Paul Mackerras <paulus@samba.org>
Cc: David Howells <dhowells@redhat.com>,
	torvalds@osdl.org, akpm@osdl.org, mingo@redhat.com,
	linux-arch@vger.kernel.org, linuxppc64-dev@ozlabs.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Document Linux's memory barriers
Date: Wed, 08 Mar 2006 18:41:30 +1100	[thread overview]
Message-ID: <440E8AAA.9030609@yahoo.com.au> (raw)
In-Reply-To: <17422.19209.60360.178668@cargo.ozlabs.ibm.com>

Paul Mackerras wrote:
> David Howells writes:

>>+     The way to deal with this is to insert an I/O memory barrier between the
>>+     two accesses:
>>+
>>+	*ADR = ctl_reg_3;
>>+	mb();
>>+	reg = *DATA;
> 
> 
> Ummm, this implies mb() is "an I/O memory barrier".  I can see people
> getting confused if they read this and then see mb() being used when
> no I/O is being done.
> 

Isn't it? Why wouldn't you just use smp_mb() if no IO is being done?

-- 
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com 

  parent reply	other threads:[~2006-03-08  7:41 UTC|newest]

Thread overview: 107+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-07 17:40 [PATCH] Document Linux's memory barriers David Howells
2006-03-07 10:34 ` Andi Kleen
2006-03-07 18:30   ` David Howells
2006-03-07 11:13     ` Andi Kleen
2006-03-07 19:24       ` David Howells
2006-03-07 19:46         ` Stephen Hemminger
2006-03-07 18:46     ` Jesse Barnes
2006-03-07 19:23     ` Bryan O'Sullivan
2006-03-07 11:57       ` Andi Kleen
2006-03-07 20:01         ` Jesse Barnes
2006-03-07 21:14         ` Bryan O'Sullivan
2006-03-07 21:24           ` Andi Kleen
2006-03-08  0:36             ` Alan Cox
2006-03-08  0:35         ` Alan Cox
2006-03-07 17:47 ` Stephen Hemminger
2006-03-07 18:40 ` Alan Cox
2006-03-07 18:54   ` linux-os (Dick Johnson)
2006-03-07 18:54     ` linux-os (Dick Johnson)
2006-03-07 19:06     ` Matthew Wilcox
2006-03-07 19:15       ` linux-os (Dick Johnson)
2006-03-07 19:15         ` linux-os (Dick Johnson)
2006-03-09 11:26         ` Sergei Organov
2006-03-07 19:33     ` Alan Cox
2006-03-07 20:09   ` David Howells
2006-03-08  0:32     ` Alan Cox
2006-03-08  8:25     ` Duncan Sands
2006-03-08 22:06       ` Paul Mackerras
2006-03-08 22:24         ` David S. Miller
2006-03-08 22:31           ` Linus Torvalds
2006-03-08 22:42         ` Alan Cox
2006-03-08  2:07 ` Nick Piggin
2006-03-08  3:10 ` Paul Mackerras
2006-03-08  3:30   ` Linus Torvalds
2006-03-08 12:34     ` David Howells
2006-03-08 16:40       ` Bryan O'Sullivan
2006-03-08  7:41   ` Nick Piggin [this message]
2006-03-08 13:19   ` David Howells
2006-03-08 21:49     ` Paul Mackerras
2006-03-08 22:05       ` Alan Cox
2006-03-10  0:49     ` H. Peter Anvin
2006-03-08 14:37 ` [PATCH] Document Linux's memory barriers [try #2] David Howells
2006-03-08 14:55   ` Alan Cox
2006-03-08 15:41     ` Matthew Wilcox
2006-03-08 17:19       ` David Howells
2006-03-08 22:10         ` Paul Mackerras
2006-03-08 23:08           ` Ivan Kokshaysky
2006-03-09  1:01             ` Paul Mackerras
2006-03-09 16:02               ` Ivan Kokshaysky
2006-03-08 17:04     ` David Howells
2006-03-08 17:36       ` Alan Cox
2006-03-08 18:35         ` David Howells
2006-03-08 18:45           ` Alan Cox
2006-03-08 18:59             ` David Howells
2006-03-08 11:38               ` Andi Kleen
2006-03-08 19:08             ` David Howells
2006-03-08 19:26               ` Linus Torvalds
2006-03-08 19:31                 ` David Howells
2006-03-09  0:35                   ` Paul Mackerras
2006-03-09  0:54                     ` Linus Torvalds
2006-03-09  1:08                       ` Paul Mackerras
2006-03-09  1:27                         ` Linus Torvalds
2006-03-09  2:38                           ` Nick Piggin
2006-03-09  3:45                           ` Paul Mackerras
2006-03-09  4:36                             ` Jesse Barnes
2006-03-09  7:41                               ` Paul Mackerras
2006-03-09  5:38                             ` Linus Torvalds
2006-03-09 12:27                               ` David Howells
2006-03-09 11:44                             ` Michael Buesch
2006-03-09  4:34                           ` Jesse Barnes
2006-03-09  4:43                             ` Paul Mackerras
2006-03-09 10:05                               ` Jes Sorensen
2006-03-09  0:55                     ` Jesse Barnes
2006-03-09  1:57                       ` Paul Mackerras
2006-03-09  4:26                         ` Jesse Barnes
2006-03-08 19:40                 ` Matthew Wilcox
2006-03-09  0:37                   ` Paul Mackerras
2006-03-09  0:59                     ` Jesse Barnes
2006-03-09  1:36                       ` Paul Mackerras
2006-03-09  4:18                         ` Jesse Barnes
2006-03-08 19:54                 ` Jesse Barnes
2006-03-08 20:02                 ` Alan Cox
2006-03-08 22:01     ` Paul Mackerras
2006-03-08 22:23       ` David S. Miller
2006-03-08 19:37   ` [PATCH] Document Linux's memory barriers [try #3] David Howells
2006-03-09 14:01     ` David Howells
2006-03-09 12:02   ` [PATCH] Document Linux's memory barriers [try #2] Sergei Organov
2006-03-08 16:18 ` [PATCH] Document Linux's memory barriers Pavel Machek
2006-03-08 20:16   ` David Howells
2006-03-08 22:01     ` Alan Cox
2006-03-09 11:41       ` David Howells
2006-03-09 12:28         ` Alan Cox
2006-03-09 13:02           ` David Howells
2006-03-09 16:32         ` Linus Torvalds
2006-03-09 17:39           ` David Howells
2006-03-09 17:54             ` Linus Torvalds
2006-03-09 17:56               ` Linus Torvalds
2006-03-08 16:26 ` Christoph Lameter
2006-03-08 17:35   ` David Howells
2006-03-08 17:46     ` Christoph Lameter
2006-03-08 17:59       ` Alan Cox
  -- strict thread matches above, loose matches on Subject: below --
2006-03-07 23:17 Chuck Ebbert
2006-03-08  0:15 ` David S. Miller
2006-03-08  0:24 ` Roberto Nibali
     [not found] <5NONi-2hp-3@gated-at.bofh.it>
     [not found] ` <5NOtZ-1FO-27@gated-at.bofh.it>
     [not found]   ` <5NPgs-2Rw-37@gated-at.bofh.it>
     [not found]     ` <5NPq4-34a-23@gated-at.bofh.it>
2006-03-08  0:22       ` Robert Hancock
     [not found] ` <5NQ2U-462-29@gated-at.bofh.it>
     [not found]   ` <5NRLg-6LJ-31@gated-at.bofh.it>
     [not found]     ` <5NRUR-6Yo-11@gated-at.bofh.it>
     [not found]       ` <5NUSF-30Z-5@gated-at.bofh.it>
2006-03-08  1:10         ` Robert Hancock
2006-03-08 11:35           ` Alan Cox
2006-03-08 14:55           ` Andi Kleen

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=440E8AAA.9030609@yahoo.com.au \
    --to=nickpiggin@yahoo.com.au \
    --cc=akpm@osdl.org \
    --cc=dhowells@redhat.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc64-dev@ozlabs.org \
    --cc=mingo@redhat.com \
    --cc=paulus@samba.org \
    --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.