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Date: Wed, 28 Nov 2001 12:18:08 +0000 (GMT)
From: Tigran Aivazian <tigran@veritas.com>
To: Frank Cornelis <Frank.Cornelis@rug.ac.be>
cc: linux-kernel@vger.kernel.org
Subject: Re: task_struct.mm == NULL
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Hi Frank,

It can be NULL for kernel threads which do not have a user address
space. Nevertheless, their tsk->active_mm would not be NULL but point to
some process' address space.

The point of  having active_mm is to minimize TLB flushes on switching
address spaces when the task is scheduled out.

Regards,
Tigran

On Wed, 28 Nov 2001, Frank Cornelis wrote:

> Hey,
> 
> I found in some code checks for task_struct.mm being NULL.
> When can task_struct.mm of a process be NULL except right before the
> process-kill?
> 
> Frank.
> 
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