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Subject: Re: [PATCH repost] sched: export sched_set/getaffinity to modules
From: Peter Zijlstra <peterz@infradead.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>, Sridhar Samudrala <sri@us.ibm.com>,
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On Thu, 2010-07-01 at 13:19 +0200, Peter Zijlstra wrote:
> On Thu, 2010-07-01 at 14:07 +0300, Michael S. Tsirkin wrote:
> > Author: Sridhar Samudrala <sri@us.ibm.com>
> > 
> > sched: export sched_set/getaffinity to modules
> > 
> > vhost-net driver wants to copy the affinity from the
> > owner thread to thread it creates. Export
> > sched_set/get affinity to modules to make this possible
> > when vhost is built as a module.

> Urgh,.. so why again is that a good idea?

In particular:
 - who sets the affinity of the task? 
 - why can't it set the kernel thread's affinity too?
 - what happens if someone changes the tasks' affinity?

So no, I don't think this is a sensible thing to do at all.
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