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From: Jens Osterkamp <jens@de•ibm.com>
To: Nathan Lynch <ntl@pobox•com>
Cc: maxim@de•ibm.com, linuxppc-dev@ozlabs•org,
	Paul Mackerras <paulus@samba•org>,
	cbe-oss-dev@ozlabs•org
Subject: Re: [PATCH] RTAS - adapt procfs interface
Date: Wed, 2 Apr 2008 13:33:22 +0200	[thread overview]
Message-ID: <200804021333.22799.jens@de.ibm.com> (raw)
In-Reply-To: <20080401163504.GP7137@localdomain>

On Tuesday 01 April 2008, Nathan Lynch wrote:
> Jens Osterkamp wrote:
> > 
> > Handling of the proc_dir_entry->count has being changed in 2.6.24-rc5.
> 
> Do you know which commit caused the change?

Yes, we bisected it to the following commit :

commit 5a622f2d0f86b316b07b55a4866ecb5518dd1cf7
Author: Alexey Dobriyan <adobriyan@sw•ru>
Date:   Tue Dec 4 23:45:28 2007 -0800

    proc: fix proc_dir_entry refcounting
    
    Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
    Switch to usual scheme:
    * PDE is created with refcount 1
    * every de_get does +1
    * every de_put() and remove_proc_entry() do -1
    * once refcount reaches 0, PDE is freed.
    
    This elegantly fixes at least two following races (both observed) without
    introducing new locks, without abusing old locks, without spreading
    lock_kernel():

    [...]

Gruß,

Jens

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  parent reply	other threads:[~2008-04-02 11:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-01 13:12 [PATCH] RTAS - adapt procfs interface Jens Osterkamp
2008-04-01 16:35 ` Nathan Lynch
2008-04-01 20:04   ` Nathan Lynch
2008-04-02 11:34     ` Jens Osterkamp
2008-04-02 11:48     ` Paul Mackerras
2008-04-02 18:54       ` Nathan Lynch
2008-04-02 11:33   ` Jens Osterkamp [this message]
2008-04-04  0:12 ` Christoph Hellwig
2008-04-04  5:39   ` [Cbe-oss-dev] " Arnd Bergmann
2008-04-04  9:15     ` Christoph Hellwig

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