Messages in this thread | | | Date | Fri, 18 Nov 2016 16:10:17 +0100 | From | luca abeni <> | Subject | Re: [RFC v3 1/6] Track the active utilisation |
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On Fri, 18 Nov 2016 15:23:59 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Oct 25, 2016 at 09:58:11AM -0400, Steven Rostedt wrote: > > > I agree with Daniel, especially since I don't usually trust the > > compiler. And the added variable is more of a distraction as it > > doesn't seem to have any real purpose. > > I don't think there's anything here to trust the compiler on. Either > it inlines or it doesn't, it should generate 'correct' code either > way. > > If it doesn't inline, its a dumb compiler and it will make these dumb > decisions throughout the tree and your kernel will be slow, not my > problem really ;-) > > That said, I agree that the single line thing is actually easier to > read.
Ok; I already made that change locally.
> > That said; there's something to be said for: > > u64 running_bw;
Ok; I originally made it signed because I wanted the "running_bw < 0" check, but I can change it to "dl_rq->running_bw > old" (I did not think about it).
I'll make these changes locally ASAP.
Thanks, Luca
> > static void add_running_bw(struct sched_dl_entity *dl_se, struct > dl_rq *dl_rq) { > u64 old = dl_rq->running_bw; > > dl_rq->running_bw += dl_se->dl_bw; > SCHED_WARN_ON(dl_rq->running_bw < old); /* overflow */ > } > > static void sub_running_bw(struct sched_dl_entity *dl_se, struct > dl_rq *dl_rq) { > u64 old = dl_rq->running_bw; > > dl_rq->running_bw -= dl_se->dl_bw; > SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */ > } > >
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