Re: [PATCH] stop on cpu lost

From: KAMEZAWA Hiroyuki
Date: Thu Jun 22 2006 - 12:05:24 EST


On Thu, 22 Jun 2006 08:45:55 -0700 (PDT)
Christoph Lameter <clameter@xxxxxxx> wrote:

> On Thu, 22 Jun 2006, Randy.Dunlap wrote:
>
> > Sounds much better than just killing the process.
>
> Right and having active interrupts or devices using that processor should
> also stop offlining a processor.
>
> So just remove everything from a processor before offlining. If you cannot
> remove all users then the processor cannot be offlined.
>
Hm..
Then, there is several ways to manage this sitation.

1. migrate all even if it's not allowed by users
2. kill mis-configured tasks.
3. stop ...
4. cancel cpu-hot-removal.

I just don't like "1".
I discussed this problem with my colleagues before sending patch,
one said "4" seems regular way but another said "4" is bad.

I sent a patch for "4" in the first place but Andi Kleen said it's bad.
As he said, I'm handling the problem for which I can't find a good answer :(

my point is that "1" is bad.
-Kame

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