public inbox for linux-arch@vger.kernel.org
 help / color / mirror / Atom feed
From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Linus Torvalds <torvalds@osdl.org>
Cc: David Howells <dhowells@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	mingo@redhat.com, akpm@osdl.org
Subject: Re: [PATCH 1/12]: MUTEX: Implement mutexes
Date: Sat, 17 Dec 2005 21:44:02 +0000	[thread overview]
Message-ID: <20051217214401.GB31551@flint.arm.linux.org.uk> (raw)
In-Reply-To: <Pine.LNX.4.64.0512171201200.3698@g5.osdl.org>

On Sat, Dec 17, 2005 at 12:11:39PM -0800, Linus Torvalds wrote:
> Of the other architectures you list, only ARM is really important. And no, 
> arm doesn't do swap. It does LL/SC (except they call it "ldrex/strex", 
> which I assume stands for "load/store with reservation and X just because 
> X is cool. Yeah, we're cool" (*)).

> (*) Actually, some arm docs I found implies that "ex" stands for 
> "exclusive", but that leaves me wondering what the "r" stands for? 

FYI.  The standard instructions:

ldr = load register
str = store register

The new (ARM architecture v6 and above) atomic instructions:

ldrex = load register exclusive
strex = store register exclusive

Previous architecture versions only have the 32-bit and 8 bit
unconditional swap instructions.  Luckily they're unlikely to be
used for SMP in the field.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core

  reply	other threads:[~2005-12-17 21:44 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-12-16 23:13 [PATCH 0/12]: MUTEX: Introduce mutex implementation David Howells
2005-12-16 23:13 ` [PATCH 1/12]: MUTEX: Implement mutexes David Howells
2005-12-17  3:58   ` Steven Rostedt
2005-12-17  7:35     ` Linus Torvalds
2005-12-17 19:21       ` David Howells
2005-12-17 20:11         ` Linus Torvalds
2005-12-17 21:44           ` Russell King [this message]
2005-12-18  1:29           ` Nicolas Pitre
2005-12-18  2:34             ` Linus Torvalds
2005-12-18  4:07               ` Nicolas Pitre
2005-12-18  4:18                 ` Steven Rostedt
2005-12-18  6:30                 ` Linus Torvalds
2005-12-18  9:26                   ` Russell King
2005-12-18 18:42                     ` Linus Torvalds
2005-12-18 19:41                       ` James Bottomley
2005-12-18 19:54                         ` Linus Torvalds
2005-12-19  1:48                       ` Nicolas Pitre
2005-12-19  9:27                         ` Russell King
2005-12-19 13:54                           ` Matthew Wilcox
2005-12-19 15:49                             ` Nicolas Pitre
2005-12-19 15:45                           ` Nicolas Pitre
2005-12-18 17:29                   ` Nicolas Pitre
2005-12-18 13:38             ` Alan Cox
2005-12-18 17:21               ` Nicolas Pitre
2005-12-17  7:55     ` Nick Piggin
2005-12-17 12:36       ` Steven Rostedt
2005-12-16 23:13 ` [PATCH 3/12]: MUTEX: Rename DECLARE_MUTEX for arch/ dir David Howells
2005-12-16 23:13 ` [PATCH 2/12]: MUTEX: Provide SWAP-based mutex for FRV David Howells
2005-12-16 23:13 ` [PATCH 4/12]: MUTEX: Rename DECLARE_MUTEX for drivers/ dir, A thru M David Howells
2005-12-16 23:13 ` [PATCH 6/12]: MUTEX: Rename DECLARE_MUTEX for fs/ dir David Howells
2005-12-16 23:13 ` [PATCH 10/12]: MUTEX: Rename DECLARE_MUTEX for sound/ dir David Howells
2005-12-16 23:13 ` [PATCH 7/12]: MUTEX: Rename DECLARE_MUTEX for include/asm-*/ dirs David Howells
2005-12-16 23:13 ` [PATCH 8/12]: MUTEX: Rename DECLARE_MUTEX for kernel/ dir David Howells
2005-12-16 23:13 ` [PATCH 9/12]: MUTEX: Rename DECLARE_MUTEX for net/ dir David Howells
2005-12-16 23:13 ` [PATCH 5/12]: MUTEX: Rename DECLARE_MUTEX for drivers/ dir, N thru Z David Howells
2005-12-16 23:13 ` [PATCH 11/12]: MUTEX: Rename DECLARE_MUTEX for miscellaneous directories David Howells
2005-12-16 23:13 ` [PATCH 12/12]: MUTEX: Provide synchronisation primitive testing module David Howells

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=20051217214401.GB31551@flint.arm.linux.org.uk \
    --to=rmk+lkml@arm.linux.org.uk \
    --cc=akpm@osdl.org \
    --cc=dhowells@redhat.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=rostedt@goodmis.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox