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From: Andrew Morton <akpm@osdl.org>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ipc 1/3: Add refcount to ipc_rcu_alloc
Date: Sat, 3 Jul 2004 13:22:17 -0700	[thread overview]
Message-ID: <20040703132217.2754ea75.akpm@osdl.org> (raw)
In-Reply-To: <40E6EE71.9050402@colorfullife.com>

Manfred Spraul <manfred@colorfullife.com> wrote:
>
> the lifetime of the ipc objects (sem array, msg queue, shm mapping) is 
>  controlled by kern_ipc_perms->lock - a spinlock. There is no simple way 
>  to reacquire this spinlock after it was dropped to 
>  schedule()/kmalloc/copy_{to,from}_user/whatever.
> 
>  The attached patch adds a reference count as a preparation to get rid of 
>  sem_revalidate().

The pointer offsetting tricks are rather unattractive.  Is it not possible
to simple aggregate the refcount into the refcounted structure, use
container_of()?


  reply	other threads:[~2004-07-03 20:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-07-03 17:35 Manfred Spraul
2004-07-03 20:22 ` Andrew Morton [this message]
2004-07-03 21:52   ` Manfred Spraul
2004-07-03 22:44     ` Andrew Morton
2004-07-03 23:10       ` Manfred Spraul

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