Messages in this thread | | | Date | Thu, 26 Jul 2012 17:54:09 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/1] kthread: disable preemption during complete() |
| |
On 07/26, Thomas Gleixner wrote: > > On Thu, 26 Jul 2012, Peter Zijlstra wrote: > > On Wed, 2012-07-25 at 15:40 -0700, Tejun Heo wrote: > > > > This patch disables preemption during complete(), since we call > > > > schedule() directly afterwards, so it will correctly enter > > > > TASK_UNINTERRUPTIBLE. This speeds up kthread creation/binding during > > > > cpu hotplug significantly. > > > > tglx has patches that make the kthread create/destroy stuff from hotplug > > go away.. that seems like the better approach. > > Right. That cpu hotplug setup/teardown stuff is ugly.
Could you cc me if you send these patches?
> > The comment doesn't really make that clear. > > Right, the comment is crap. It has nothing to do with kthread_bind() > and stuff. The whole purpose is to avoid the pointless preemption > after wakeup.
Yes, but this "avoid the preemption after wakeup" can actually help kthread_bind()->wait_task_inactive() ?
This reminds me, Peter had a patch which teaches wait_task_inactive() to use sched_in/sched_out notifiers to avoid the polling...
Oleg.
| |