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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: jmorris@namei.org, linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org, chrisw@sous-sol.org
Subject: Re: [TOMOYO 05/15](repost) Domain transition handler functions.
Date: Wed, 03 Oct 2007 15:24:24 +0200	[thread overview]
Message-ID: <1191417864.5599.2.camel@lappy> (raw)
In-Reply-To: <200710032204.DFF51552.OFOSOFMVQtHLJF@I-love.SAKURA.ne.jp>


On Wed, 2007-10-03 at 22:04 +0900, Tetsuo Handa wrote:
> James Morris wrote:
> > I'm pretty sure that the singly linked list idea has been rejected a few 
> > times.  Just use the existing API.
> Too bad...
> 
> Well, is there a way to avoid read_lock when reading list?
> 
> Currently, TOMOYO Linux avoids read_lock, on the assumption that
> (1) First, ptr->next is initialized with NULL.
> (2) Later, ptr->next is assigned non-NULL address.
> (3) Assigning to ptr->next is done atomically.

 (4) wmb after asigning ptr->next
 (5) rmb before reading ptr->next

But please do look at the various rcu list primitives. RCU allows one to
avoid non-exclusive locks in many cases.

non-exclusive locks are evil, they must all die...


  parent reply	other threads:[~2007-10-03 13:30 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-02  7:25 [TOMOYO 00/15](repost) TOMOYO Linux - MAC based on process invocation history Kentaro Takeda
2007-10-02  7:28 ` [TOMOYO 01/15](repost) Allow use of namespace_sem from LSM module Kentaro Takeda
2007-10-02  7:29 ` [TOMOYO 02/15](repost) Data structures and prototypes definition Kentaro Takeda
2007-10-02  7:30 ` [TOMOYO 03/15](repost) Memory and pathname management functions Kentaro Takeda
2007-10-03  7:39   ` James Morris
2007-10-03 11:12     ` Tetsuo Handa
2007-10-02  7:31 ` [TOMOYO 04/15](repost) Utility functions and securityfs interface for policy manipulation Kentaro Takeda
2007-10-02  8:05   ` Paul Mundt
2007-10-02 14:15     ` Greg KH
2007-10-02  7:32 ` [TOMOYO 05/15](repost) Domain transition handler functions Kentaro Takeda
2007-10-02 11:15   ` James Morris
2007-10-02 12:44     ` Tetsuo Handa
2007-10-02 13:00       ` YOSHIFUJI Hideaki / 吉藤英明
2007-10-02 13:07       ` James Morris
2007-10-02 14:50         ` Andi Kleen
2007-10-03 11:24         ` Tetsuo Handa
2007-10-03 11:43           ` YOSHIFUJI Hideaki / 吉藤英明
2007-10-03 12:37             ` James Morris
2007-10-03 13:04               ` Tetsuo Handa
2007-10-03 13:11                 ` YOSHIFUJI Hideaki / 吉藤英明
2007-10-03 13:14                 ` KaiGai Kohei
2007-10-03 13:59                   ` Tetsuo Handa
2007-10-03 14:07                     ` Peter Zijlstra
2007-10-03 14:26                       ` Tetsuo Handa
2007-10-03 14:26                         ` Peter Zijlstra
2007-10-03 14:32                         ` YOSHIFUJI Hideaki / 吉藤英明
2007-10-03 14:39                           ` James Morris
2007-10-03 14:56                           ` Tetsuo Handa
2007-10-04 12:57                             ` Tetsuo Handa
2007-10-03 14:37                         ` Jiri Kosina
2007-10-07 10:38                       ` Sleeping in RCU list traversal Tetsuo Handa
2007-10-03 13:24                 ` Peter Zijlstra [this message]
2007-10-03 14:19                   ` [TOMOYO 05/15](repost) Domain transition handler functions Tetsuo Handa
2007-10-03 14:28                     ` Peter Zijlstra
2007-10-15 11:46                       ` Tetsuo Handa
2007-10-03 14:35                     ` David P. Quigley
2007-10-15 12:09               ` Tetsuo Handa
2007-10-02  7:33 ` [TOMOYO 06/15](repost) Auditing interface Kentaro Takeda
2007-10-02  7:34 ` [TOMOYO 07/15](repost) File access control functions Kentaro Takeda
2007-10-02  7:35 ` [TOMOYO 08/15](repost) Argv[0] " Kentaro Takeda
2007-10-02  7:36 ` [TOMOYO 09/15](repost) Networking " Kentaro Takeda
2007-10-02  7:37 ` [TOMOYO 10/15](repost) Namespace manipulation " Kentaro Takeda
2007-10-02  7:37 ` [TOMOYO 11/15](repost) Signal transmission " Kentaro Takeda
2007-10-02  7:38 ` [TOMOYO 12/15](repost) LSM adapter for TOMOYO Kentaro Takeda
2007-10-02  7:39 ` [TOMOYO 13/15](repost) Conditional permission support Kentaro Takeda
2007-10-02  7:39 ` [TOMOYO 14/15](repost) LSM expansion for TOMOYO Linux Kentaro Takeda
2007-10-02 12:48   ` James Morris
2007-10-02 13:33     ` Tetsuo Handa
2007-10-02 14:36   ` James Morris
2007-10-02 21:49     ` Tetsuo Handa
2007-10-02  7:40 ` [TOMOYO 15/15](repost) Kconfig and Makefile " Kentaro Takeda
2007-10-02  7:42 ` [TOMOYO 00/15](repost) TOMOYO Linux - MAC based on process invocation history Kentaro Takeda
2007-10-02 10:37   ` James Morris
2007-10-02 10:58     ` Kentaro Takeda

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