Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1369248

Re: [PATCH] sched/deadline: No need to check NULL later_mask

Show all headers | View raw

On 2016/04/01 at 19:29, Peter Zijlstra wrote:
> On Fri, Apr 01, 2016 at 07:13:18PM +0800, Xunlei Pang wrote:
>> Unlike rt tasks, we (should) have no deadline tasks in
>> booting phase before the mask is allocated, so we can
>> safely remove the check.
> Why? And have the kernel explode once it grows an early deadline task?
>
> Is there _any_ benefit to this?

This is a performance-critical path, it'd be better to avoid such a check.

I think in the early boot stage before sched_init_smp(), it's weird to
use a deadline task, relying on rt tasks should be enough for us.

Please ignore it if you don't think so :-)

Regards,
Xunlei

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] sched/deadline: No need to check NULL later_mask Xunlei Pang <xlpang@redhat.com> - 2016-04-01 13:20 +0200
  Re: [PATCH] sched/deadline: No need to check NULL later_mask Peter Zijlstra <peterz@infradead.org> - 2016-04-01 13:30 +0200
    Re: [PATCH] sched/deadline: No need to check NULL later_mask Xunlei Pang <xpang@redhat.com> - 2016-04-01 14:20 +0200
      Re: [PATCH] sched/deadline: No need to check NULL later_mask Peter Zijlstra <peterz@infradead.org> - 2016-04-01 18:30 +0200
        Re: [PATCH] sched/deadline: No need to check NULL later_mask Xunlei Pang <xpang@redhat.com> - 2016-04-02 12:20 +0200

csiph-web