On Thu, Jul 01, 2010 at 02:46:35PM +0200, Peter Zijlstra wrote:

On Thu, 2010-07-01 at 14:34 +0200, Peter Zijlstra wrote:

quoted

On Thu, 2010-07-01 at 15:23 +0300, Michael S. Tsirkin wrote:

quoted

The patch using this is here:
http://www.mail-archive.com/kvm@vger.kernel.org/msg35411.html

It simply copies the affinity from the parent when thread is created.

Sounds like policy, not something the kernel should do..

The alternative would be using clone() instead of thread_create() and
inherit everything from the creating task.
Inheriting from kthreadd and then undoing some aspects just sounds
like daft policy that really ought to be in userspace.

Yes, that's basically what this patchset is trying to do:
create a workqueue inheriting everything from the creating task.
Sridhar started with an API to do exactly this:
http://linux.derkeiler.com/Mailing-Lists/Kernel/2010-05/msg07478.html

Then we switched to raw kthread to avoid stepping on cwq toes.
Maybe it makes sense to add kthread_clone (in addition to
kthread_create) that would do what you suggest?
If yes, any hints on an implementation?


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MST