Hi Tommaso, On 18/05/16 00:43, Tommaso Cucinotta wrote: > On 17/05/2016 13:46, luca abeni wrote: > >Maybe the ... change can be split in a separate > >patch, which is a bugfix (and IMHO uncontroversial)? > > Ok, the bugfix alone might look like the attached. Couldn't avoid > the little refactoring of the multiple occurrences of the same loop > up the heap into the heapify_up(), mirroring the heapify() that was > already there (renamed heapify_down() for clarity). > > I'll rebase the speed-up patch on top of this, if it's a better approach. > > Anyone with further comments? >
Couldn't spend any time on this yet, apologies. But, for the next posting, could you please do it without attaching the patches? I usually use git send-mail for posting. It would make the review easier, I think. Best, - Juri > Thanks again! > > T. > -- > Tommaso Cucinotta, Computer Engineering PhD > Associate Professor at the Real-Time Systems Laboratory (ReTiS) > Scuola Superiore Sant'Anna, Pisa, Italy > http://retis.sssup.it/people/tommaso > From cfaa75eb77843f7da875a54c7e6631b271bf0663 Mon Sep 17 00:00:00 2001 > From: Tommaso Cucinotta <tommaso.cucino...@sssup.it> > Date: Tue, 17 May 2016 15:54:11 +0200 > Subject: [PATCH] Deadline wrap-around bugfix for the SCHED_DEADLINE cpu heap. > > --- > kernel/sched/cpudeadline.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) > > diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c > index 5be5882..3c42702 100644 > --- a/kernel/sched/cpudeadline.c > +++ b/kernel/sched/cpudeadline.c > @@ -41,7 +41,7 @@ static void cpudl_exchange(struct cpudl *cp, int a, int b) > swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx); > } > > -static void cpudl_heapify(struct cpudl *cp, int idx) > +static void cpudl_heapify_down(struct cpudl *cp, int idx) > { > int l, r, largest; > > @@ -66,20 +66,25 @@ static void cpudl_heapify(struct cpudl *cp, int idx) > } > } > > +static void cpudl_heapify_up(struct cpudl *cp, int idx) > +{ > + while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl, > + cp->elements[idx].dl)) { > + cpudl_exchange(cp, idx, parent(idx)); > + idx = parent(idx); > + } > +} > + > static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl) > { > WARN_ON(idx == IDX_INVALID || !cpu_present(idx)); > > if (dl_time_before(new_dl, cp->elements[idx].dl)) { > cp->elements[idx].dl = new_dl; > - cpudl_heapify(cp, idx); > + cpudl_heapify_down(cp, idx); > } else { > cp->elements[idx].dl = new_dl; > - while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl, > - cp->elements[idx].dl)) { > - cpudl_exchange(cp, idx, parent(idx)); > - idx = parent(idx); > - } > + cpudl_heapify_up(cp, idx); > } > } > > @@ -154,24 +159,19 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int > is_valid) > cp->size--; > cp->elements[new_cpu].idx = old_idx; > cp->elements[cpu].idx = IDX_INVALID; > - while (old_idx > 0 && dl_time_before( > - cp->elements[parent(old_idx)].dl, > - cp->elements[old_idx].dl)) { > - cpudl_exchange(cp, old_idx, parent(old_idx)); > - old_idx = parent(old_idx); > - } > + cpudl_heapify_up(cp, old_idx); > cpumask_set_cpu(cpu, cp->free_cpus); > - cpudl_heapify(cp, old_idx); > + cpudl_heapify_down(cp, old_idx); > > goto out; > } > > if (old_idx == IDX_INVALID) { > - cp->size++; > - cp->elements[cp->size - 1].dl = 0; > - cp->elements[cp->size - 1].cpu = cpu; > - cp->elements[cpu].idx = cp->size - 1; > - cpudl_change_key(cp, cp->size - 1, dl); > + int size1 = cp->size++; > + cp->elements[size1].dl = dl; > + cp->elements[size1].cpu = cpu; > + cp->elements[cpu].idx = size1; > + cpudl_heapify_up(cp, size1); > cpumask_clear_cpu(cpu, cp->free_cpus); > } else { > cpudl_change_key(cp, old_idx, dl); > -- > 2.7.4 >
