Re: [PATCH] sched/rt: Document why has_pushable_tasks() isn't called with a runqueue lock

2017-03-02 Thread Steven Rostedt
On Wed, 1 Mar 2017 09:37:01 +0100 Peter Zijlstra wrote: > On Tue, Feb 28, 2017 at 04:48:56PM -0500, Steven Rostedt wrote: > > > + /* > > +* Normally, has_pushable_tasks() would be performed within the > > +* runqueue lock being held. But if it was not set when entering > > "not set"

Re: [PATCH] sched/rt: Document why has_pushable_tasks() isn't called with a runqueue lock

2017-03-01 Thread Peter Zijlstra
On Tue, Feb 28, 2017 at 04:48:56PM -0500, Steven Rostedt wrote: > + /* > + * Normally, has_pushable_tasks() would be performed within the > + * runqueue lock being held. But if it was not set when entering "not set" what? I'm having trouble parsing this. > + * this hard interr

[PATCH] sched/rt: Document why has_pushable_tasks() isn't called with a runqueue lock

2017-02-28 Thread Steven Rostedt
From: Steven Rostedt (VMware) While reviewing the RT scheduling IPI logic, I was thinking that it was a bug that has_pushable_tasks(rq) was not called under the runqueue lock. But then I realized that there isn't a case where a race would cause a problem, as to update has_pushable_tasks() would