Re: [RFC v5 5/9] sched/deadline: do not reclaim the whole CPU bandwidth

From: Peter Zijlstra
Date: Mon Mar 27 2017 - 04:36:36 EST


On Fri, Mar 24, 2017 at 10:38:31PM -0400, Steven Rostedt wrote:

> > > > @@ -6716,6 +6716,12 @@ static void sched_dl_do_global(void)
> > > > raw_spin_unlock_irqrestore(&dl_b->lock, flags);
> > > >
> > > > rcu_read_unlock_sched();
> > > > + if (dl_b->bw == -1)
> > > > + cpu_rq(cpu)->dl.deadline_bw_inv = 1 << 8;
> > > > + else
> > > > + cpu_rq(cpu)->dl.deadline_bw_inv =
> > > > + to_ratio(global_rt_runtime(),
> > > > + global_rt_period()) >>
> > > > 12;
> > >
> > > Coding style requires braces here (on both legs of the condition)..

> I'm not sure it's completely documented anywhere.

Two parts;

1) I prefer braces over any multi line block, irrespective if its a
single statement or not. This is, afaik, not strictly documented in
coding style.

Rationale is that missing braces are bad, and the larger the single
statement, the harder it is to be sure it is in fact a single
statement.


2) If one leg needs braces, then both should get it. This is in fact
part of CodingStyle.