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Reply-To: <imran.badr@cavium.com>
From: "Imran Badr" <imran.badr@cavium.com>
To: "'Manfred Spraul'" <manfred@colorfullife.com>,
       <linux-kernel@vger.kernel.org>
Subject: RE: Calculating kernel logical address ..
Date: Mon, 9 Sep 2002 14:07:34 -0700
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-----Original Message-----
From: Manfred Spraul [mailto:manfred@colorfullife.com]
Sent: Monday, September 09, 2002 2:02 PM
To: Imran Badr; linux-kernel@vger.kernel.org
Subject: RE: Calculating kernel logical address ..


>>As long as you can be sure they won't spontaneously vanish on you.
>
>>--
>>Daniel
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>>the body of a message to majordomo@vger.kernel.org
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>>Please read the FAQ at  http://www.tux.org/lkml/
>
>
>
> down(&current->mm->mmap_sem) would help.
>

>Wrong. Acquiring the mmap semaphore does NOT prevent the swapper from
>swapping out pages.

>Only the page_table_lock prevents the swapper from touching a task.

>--
>	Manfred


I think you missed the whole context of the discussion. The next step is to
call get_user_pages() which takes appropriate actions to prevent page swaps.

Thanks,
Imran.



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