On Sat, 4 Mar 2023 at 16:13, Shrikanth Hegde <sshegde@xxxxxxxxxxxxxxxxxx> wrote: > > > > On 3/3/23 10:01 PM, Vincent Guittot wrote: > > Le jeudi 02 mars 2023 à 23:37:52 (+0530), Shrikanth Hegde a écrit : > >> > >> On 3/2/23 8:30 PM, Shrikanth Hegde wrote: > >>> On 3/2/23 6:47 PM, Vincent Guittot wrote: > >>>> On Thu, 2 Mar 2023 at 12:00, Shrikanth Hegde <sshegde@xxxxxxxxxxxxxxxxxx> wrote: > >>>>> On 3/2/23 1:20 PM, Vincent Guittot wrote: > >>>>>> On Wed, 1 Mar 2023 at 19:48, shrikanth hegde <sshegde@xxxxxxxxxxxxxxxxxx> wrote: > >>>>>>> On 2/24/23 3:04 PM, Vincent Guittot wrote: > > [...] > > > >>>>>>> Ran the schbench and hackbench with this patch series. Here comparison is > >>>>>>> between 6.2 stable tree, 6.2 + Patch and 6.2 + patch + above re-arrange of > >>>>>>> latency_node. Ran two cgroups, in one cgroup running stress-ng at 50%(group1) > >>>>>>> and other is running these benchmarks (group2). Set the latency nice > >>>>>>> of group2 to -20. These are run on Power system with 12 cores with SMT=8. > >>>>>>> Total of 96 CPU. > >>>>>>> > >>>>>>> schbench gets lower latency compared to stabletree. Whereas hackbench seems > >>>>>>> to regress under this case. Maybe i am doing something wrong. I will re-run > >>>>>>> and attach the numbers to series. > >>>>>>> Please suggest if any variation in the test i need to try. > >>>>>> hackbench takes advanatge of a latency nice 19 as it mainly wants to > >>>>>> run longer slice to move forward rather than preempting others all the > >>>>>> time > >>>>> hackbench still seems to regress in different latency nice values compared to > >>>>> baseline of 6.2 in this case. up to 50% in some cases. > >>>>> > >>>>> 12 core powerpc system with SMT=8 i.e 96 CPU > >>>>> running 2 CPU cgroups. No quota assigned. > >>>>> 1st cgroup is running stress-ng with 48 threads. Consuming 50% of CPU. > >>>>> latency is not changed for this cgroup. > >>>>> 2nd cgroup is running hackbench. This cgroup is assigned the different latency > >>>>> nice values of 0, -20 and 19. > >>>> According to your other emails, you are using the cgroup interface and > >>>> not the task's one. Do I get it right ? > >>> right. I create cgroup, attach bash command with echo $$, > >>> assign the latency nice to cgroup, and run hackbench from that bash prompt. > >>> > >>>> I haven't run test such tests in a cgroup but at least the test with > >>>> latency_nice == 0 should not make any noticeable difference. Does this > >>>> include the re-arrange patch that you have proposed previously ? > >>> No. This is only with V12 of the series. > >>> > >>>> Also, the tests that you did on v6, gave better result. > >>>> https://lore.kernel.org/lkml/34112324-de67-55eb-92bc-181a98c4311c@xxxxxxxxxxxxxxxxxx/ > >>>> > >>>> Are you running same tests or you changed something in the mean time ? > >>> Test machine got changed. > >>> now i re-read my earlier mail. I see it was slightly different. > >>> I had created only one cgroup and stress-ng was run > >>> without any cgroup. Let me try that scenario and get the numbers. > >> > >> Tried the same method of testing i had done on V7 of the series. on this > >> machine hackbench still regress's both on V12 as well as V7 of the series. > >> > >> Created one cpu cgroup called cgroup1. created two bash prompts. > >> assigned "bash $$" to cgroup1 and on other bash prompt running, > >> stress-ng --cpu=96 -l 50. Ran hackbench from cgroup1 prompt. > >> assigned latency values to the cgroup1. > > I have tried to reproduce your results on some of my systems but I can't see > > the impacts that you are reporting below. > > The fact that your other platform was not impacted as well could imply that > > it's specific to this platform. > > In particular, the lat nice=0 case should not show any real impact as it > > should be similar to a nop. At least that what I can see in the tests on my > > platforms and Prateek on his. > > > > Nevertheless, could you try to run your tests with the changes below ? > > These are the only places which could have an impact even with lat nice = 0 > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 8137bca80572..979571a98b28 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -4991,8 +4991,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) > > if (delta < offset) > > return; > > > > - if ((delta > ideal_runtime) || > > - (delta > get_latency_max())) > > + if (delta > ideal_runtime) > > resched_curr(rq_of(cfs_rq)); > > } > > > > @@ -7574,9 +7573,10 @@ static long wakeup_latency_gran(struct sched_entity *curr, struct sched_entity * > > * Otherwise, use the latency weight to evaluate how much scheduling > > * delay is acceptable by se. > > */ > > - if ((latency_offset < 0) || (curr->latency_offset < 0)) > > + if ((latency_offset < 0) || (curr->latency_offset < 0)) { > > latency_offset -= curr->latency_offset; > > - latency_offset = min_t(long, latency_offset, get_latency_max()); > > + latency_offset = min_t(long, latency_offset, get_latency_max()); > > + } > > > > return latency_offset; > > } > > @@ -7635,7 +7635,6 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) > > * for low priority task. Make sure that long sleeping task will get a > > * chance to preempt current. > > */ > > - gran = min_t(s64, gran, get_latency_max()); > > > > if (vdiff > gran) > > return 1; > > > > Above patch helps. thank you. Great. At least we have narrow the problem to one f the 3 changes. > Numbers are comparable to 6.2 and there is slight improvement. Much better than V12 numbers. > > type groups | v6.2 |v6.2 + V12| v6.2 + V12 | v6.2 + V12 > | |lat nice=0| lat nice=-20| lat nice=+19 > > Process 10 | 0.33 | 0.37 | 0.38 | 0.37 > Process 20 | 0.61 | 0.67 | 0.68 | 0.67 > Process 30 | 0.85 | 0.95 | 0.95 | 0.96 > Process 40 | 1.10 | 1.20 | 1.20 | 1.21 > Process 50 | 1.34 | 1.47 | 1.44 | 1.45 > Process 60 | 1.57 | 1.70 | 1.71 | 1.70 > thread 10 | 0.36 | 0.40 | 0.39 | 0.39 > thread 20 | 0.65 | 0.72 | 0.71 | 0.71 > Process(Pipe) 10 | 0.18 | 0.31 | 0.31 | 0.33 > Process(Pipe) 20 | 0.32 | 0.51 | 0.50 | 0.50 > Process(Pipe) 30 | 0.43 | 0.65 | 0.67 | 0.67 > Process(Pipe) 40 | 0.57 | 0.82 | 0.83 | 0.83 > Process(Pipe) 50 | 0.67 | 1.00 | 0.97 | 0.98 > Process(Pipe) 60 | 0.81 | 1.13 | 1.11 | 1.12 > thread(Pipe) 10 | 0.19 | 0.33 | 0.33 | 0.33 > thread(Pipe) 20 | 0.34 | 0.53 | 0.51 | 0.52 > > > > type groups | v6.2 |v6.2+ V12+ | v6.2 + V12+| v6.2 + V12 > | |above patch|above patch | above patch > | |lat nice=0 |lat nice=-20| lat nice=+19 > > Process 10 | 0.36 | 0.33 | 0.34 | 0.34 > Process 20 | 0.62 | 0.60 | 0.61 | 0.61 > Process 30 | 0.87 | 0.84 | 0.85 | 0.84 > Process 40 | 1.13 | 1.09 | 1.10 | 1.09 > Process 50 | 1.38 | 1.33 | 1.33 | 1.34 > Process 60 | 1.64 | 1.56 | 1.58 | 1.56 > thread 10 | 0.35 | 0.35 | 0.35 | 0.35 > thread 20 | 0.64 | 0.63 | 0.63 | 0.63 > Process(Pipe) 10 | 0.20 | 0.18 | 0.18 | 0.18 > Process(Pipe) 20 | 0.32 | 0.31 | 0.31 | 0.32 > Process(Pipe) 30 | 0.44 | 0.43 | 0.43 | 0.43 > Process(Pipe) 40 | 0.56 | 0.57 | 0.56 | 0.55 > Process(Pipe) 50 | 0.70 | 0.67 | 0.67 | 0.67 > Process(Pipe) 60 | 0.83 | 0.79 | 0.81 | 0.80 > thread(Pipe) 10 | 0.21 | 0.19 | 0.19 | 0.19 > thread(Pipe) 20 | 0.35 | 0.33 | 0.34 | 0.33 > > > Do you want me to try any other experiment on this further? Yes, would be good to know which of the 3 changes in the patch create the regression I suspect the 1st change to be the root cause of your problem but It would be good if you can confirm my assumption with some tests Thanks > > >> I will try to run with only task's set with latency_nice=0 as well. > >> > >> type groups | v6.2 |v6.2 + V12| v6.2 + V12 | v6.2 + V12 > >> | |lat nice=0| lat nice=-20| lat nice=+19 > >> > >> Process 10 | 0.33 | 0.37 | 0.38 | 0.37 > >> Process 20 | 0.61 | 0.67 | 0.68 | 0.67 > >> Process 30 | 0.85 | 0.95 | 0.95 | 0.96 > >> Process 40 | 1.10 | 1.20 | 1.20 | 1.21 > >> Process 50 | 1.34 | 1.47 | 1.44 | 1.45 > >> Process 60 | 1.57 | 1.70 | 1.71 | 1.70 > >> thread 10 | 0.36 | 0.40 | 0.39 | 0.39 > >> thread 20 | 0.65 | 0.72 | 0.71 | 0.71 > >> Process(Pipe) 10 | 0.18 | 0.31 | 0.31 | 0.33 > >> Process(Pipe) 20 | 0.32 | 0.51 | 0.50 | 0.50 > >> Process(Pipe) 30 | 0.43 | 0.65 | 0.67 | 0.67 > >> Process(Pipe) 40 | 0.57 | 0.82 | 0.83 | 0.83 > >> Process(Pipe) 50 | 0.67 | 1.00 | 0.97 | 0.98 > >> Process(Pipe) 60 | 0.81 | 1.13 | 1.11 | 1.12 > >> thread(Pipe) 10 | 0.19 | 0.33 | 0.33 | 0.33 > >> thread(Pipe) 20 | 0.34 | 0.53 | 0.51 | 0.52 > >> > >> > >> > >> type groups | v6.2 |v6.2 + V7 | v6.2 + V7 | v6.2 + V7 > >> | |lat nice=0|lat nice=-20| lat nice=+19 > >> Process 10 | 0.33 | 0.37 | 0.37 | 0.37 > >> Process 20 | 0.61 | 0.67 | 0.67 | 0.67 > >> Process 30 | 0.85 | 0.96 | 0.94 | 0.95 > >> Process 40 | 1.10 | 1.20 | 1.20 | 1.20 > >> Process 50 | 1.34 | 1.45 | 1.46 | 1.45 > >> Process 60 | 1.57 | 1.71 | 1.68 | 1.72 > >> thread 10 | 0.36 | 0.40 | 0.40 | 0.40 > >> thread 20 | 0.65 | 0.71 | 0.71 | 0.71 > >> Process(Pipe) 10 | 0.18 | 0.30 | 0.30 | 0.31 > >> Process(Pipe) 20 | 0.32 | 0.50 | 0.50 | 0.50 > >> Process(Pipe) 30 | 0.43 | 0.67 | 0.67 | 0.66 > >> Process(Pipe) 40 | 0.57 | 0.86 | 0.84 | 0.84 > >> Process(Pipe) 50 | 0.67 | 0.99 | 0.97 | 0.97 > >> Process(Pipe) 60 | 0.81 | 1.10 | 1.13 | 1.13 > >> thread(Pipe) 10 | 0.19 | 0.34 | 0.34 | 0.33 > >> thread(Pipe) 20 | 0.34 | 0.55 | 0.53 | 0.54 > >> > >>>>> Numbers are average of 10 runs in each case. Time is in seconds > >>>>> > >>>>> type groups | v6.2 | v6.2 + V12 | v6.2 + V12 | v6.2 + V12 > >>>>> | | lat nice=0 | lat nice=-20| lat nice=+19 > >>>>> | | | | > >>>>> Process 10 | 0.36 | 0.41 | 0.43 | 0.42 > >>>>> Process 20 | 0.62 | 0.76 | 0.75 | 0.75 > >>>>> Process 30 | 0.87 | 1.05 | 1.04 | 1.06 > >>>>> Process 40 | 1.13 | 1.34 | 1.33 | 1.33 > >>>>> Process 50 | 1.38 | 1.62 | 1.66 | 1.63 > >>>>> Process 60 | 1.64 | 1.91 | 1.97 | 1.90 > >>>>> thread 10 | 0.35 | 0.41 | 0.44 | 0.42 > >>>>> thread 20 | 0.64 | 0.78 | 0.77 | 0.79 > >>>>> Process(Pipe) 10 | 0.20 | 0.34 | 0.33 | 0.34 > >>>>> Process(Pipe) 20 | 0.32 | 0.52 | 0.53 | 0.52 > >>>>> Process(Pipe) 30 | 0.44 | 0.70 | 0.70 | 0.69 > >>>>> Process(Pipe) 40 | 0.56 | 0.88 | 0.89 | 0.88 > >>>>> Process(Pipe) 50 | 0.70 | 1.08 | 1.08 | 1.07 > >>>>> Process(Pipe) 60 | 0.83 | 1.27 | 1.27 | 1.26 > >>>>> thread(Pipe) 10 | 0.21 | 0.35 | 0.34 | 0.36 > >>>>> thread(Pipe) 10 | 0.35 | 0.55 | 0.58 | 0.55 > >>>>> > >>>>> > >>>>> > >>>>>>> Re-arrange seems to help the patch series by avoiding an cacheline miss. > >>>>>>> > >>>>>>> ========================= > >>>>>>> schbench > >>>>>>> ========================= > >>>>>>> 6.2 | 6.2 + V12 | 6.2 + V12 + re-arrange > >>>>>>> 1 Thread > >>>>>>> 50.0th: 9.00 | 9.00 | 9.50 > >>>>>>> 75.0th: 10.50 | 10.00 | 9.50 > >>>>>>> 90.0th: 11.00 | 11.00 | 10.50 > >>>>>>> 95.0th: 11.00 | 11.00 | 11.00 > >>>>>>> 99.0th: 11.50 | 11.50 | 11.50 > >>>>>>> 99.5th: 12.50 | 12.00 | 12.00 > >>>>>>> 99.9th: 14.50 | 13.50 | 12.00 > >>>>>>> 2 Threads > >>>>>>> 50.0th: 9.50 | 9.50 | 8.50 > >>>>>>> 75.0th: 11.00 | 10.50 | 9.50 > >>>>>>> 90.0th: 13.50 | 11.50 | 10.50 > >>>>>>> 95.0th: 14.00 | 12.00 | 11.00 > >>>>>>> 99.0th: 15.50 | 13.50 | 12.00 > >>>>>>> 99.5th: 16.00 | 14.00 | 12.00 > >>>>>>> 99.9th: 17.00 | 16.00 | 16.50 > >>>>>>> 4 Threads > >>>>>>> 50.0th: 11.50 | 11.50 | 10.50 > >>>>>>> 75.0th: 13.50 | 12.50 | 12.50 > >>>>>>> 90.0th: 15.50 | 14.50 | 14.00 > >>>>>>> 95.0th: 16.50 | 15.50 | 14.50 > >>>>>>> 99.0th: 20.00 | 17.50 | 16.50 > >>>>>>> 99.5th: 20.50 | 18.50 | 17.00 > >>>>>>> 99.9th: 22.50 | 21.00 | 19.00 > >>>>>>> 8 Threads > >>>>>>> 50.0th: 14.00 | 14.00 | 14.00 > >>>>>>> 75.0th: 16.00 | 16.00 | 16.00 > >>>>>>> 90.0th: 18.00 | 18.00 | 17.50 > >>>>>>> 95.0th: 18.50 | 18.50 | 18.50 > >>>>>>> 99.0th: 20.00 | 20.00 | 20.00 > >>>>>>> 99.5th: 20.50 | 21.50 | 21.00 > >>>>>>> 99.9th: 22.50 | 23.50 | 23.00 > >>>>>>> 16 Threads > >>>>>>> 50.0th: 19.00 | 18.50 | 19.00 > >>>>>>> 75.0th: 23.00 | 22.50 | 23.00 > >>>>>>> 90.0th: 25.00 | 25.50 | 25.00 > >>>>>>> 95.0th: 26.50 | 26.50 | 26.00 > >>>>>>> 99.0th: 28.50 | 29.00 | 28.50 > >>>>>>> 99.5th: 31.00 | 30.00 | 30.00 > >>>>>>> 99.9th: 5626.00 | 4761.50 | 32.50 > >>>>>>> 32 Threads > >>>>>>> 50.0th: 27.00 | 27.50 | 29.00 > >>>>>>> 75.0th: 35.50 | 36.50 | 38.50 > >>>>>>> 90.0th: 42.00 | 44.00 | 50.50 > >>>>>>> 95.0th: 447.50 | 2959.00 | 8544.00 > >>>>>>> 99.0th: 7372.00 | 17032.00 | 19136.00 > >>>>>>> 99.5th: 15360.00 | 19808.00 | 20704.00 > >>>>>>> 99.9th: 20640.00 | 30048.00 | 30048.00 > >>>>>>> > >>>>>>> ==================== > >>>>>>> hackbench > >>>>>>> ==================== > >>>>>>> 6.2 | 6.2 + V12 | 6.2+ V12 +re-arrange > >>>>>>> > >>>>>>> Process 10 Time: 0.35 | 0.42 | 0.41 > >>>>>>> Process 20 Time: 0.61 | 0.76 | 0.76 > >>>>>>> Process 30 Time: 0.87 | 1.06 | 1.05 > >>>>>>> thread 10 Time: 0.35 | 0.43 | 0.42 > >>>>>>> thread 20 Time: 0.66 | 0.79 | 0.78 > >>>>>>> Process(Pipe) 10 Time: 0.21 | 0.33 | 0.32 > >>>>>>> Process(Pipe) 20 Time: 0.34 | 0.52 | 0.52 > >>>>>>> Process(Pipe) 30 Time: 0.46 | 0.72 | 0.71 > >>>>>>> thread(Pipe) 10 Time: 0.21 | 0.34 | 0.34 > >>>>>>> thread(Pipe) 20 Time: 0.36 | 0.56 | 0.56 > >>>>>>> > >>>>>>> > >>>>>>>> struct list_head group_node; > >>>>>>>> unsigned int on_rq; > >>>>>>>> > >>>>>>>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c > >>>>>>>> index 093cc1af73dc..752fd364216c 100644 > >>>>>>>> --- a/kernel/sched/core.c > >>>>>>>> +++ b/kernel/sched/core.c > >>>>>>>> @@ -4434,6 +4434,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) > >>>>>>>> p->se.nr_migrations = 0; > >>>>>>>> p->se.vruntime = 0; > >>>>>>>> INIT_LIST_HEAD(&p->se.group_node); > >>>>>>>> + RB_CLEAR_NODE(&p->se.latency_node); > >>>>>>>> > >>>>>>>> #ifdef CONFIG_FAIR_GROUP_SCHED > >>>>>>>> p->se.cfs_rq = NULL; > >>>>>>>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > >>>>>>>> index 125a6ff53378..e2aeb4511686 100644 > >>>>>>>> --- a/kernel/sched/fair.c > >>>>>>>> +++ b/kernel/sched/fair.c > >>>>>>>> @@ -680,7 +680,85 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) > >>>>>>>> > >>>>>>>> return __node_2_se(last); > >>>>>>>> } > >>>>>>>> +#endif > >>>>>>>> > >>>>>>>> +/************************************************************** > >>>>>>>> + * Scheduling class tree data structure manipulation methods: > >>>>>>>> + * for latency > >>>>>>>> + */ > >>>>>>>> + > >>>>>>>> +static inline bool latency_before(struct sched_entity *a, > >>>>>>>> + struct sched_entity *b) > >>>>>>>> +{ > >>>>>>>> + return (s64)(a->vruntime + a->latency_offset - b->vruntime - b->latency_offset) < 0; > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> +#define __latency_node_2_se(node) \ > >>>>>>>> + rb_entry((node), struct sched_entity, latency_node) > >>>>>>>> + > >>>>>>>> +static inline bool __latency_less(struct rb_node *a, const struct rb_node *b) > >>>>>>>> +{ > >>>>>>>> + return latency_before(__latency_node_2_se(a), __latency_node_2_se(b)); > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> +/* > >>>>>>>> + * Enqueue an entity into the latency rb-tree: > >>>>>>>> + */ > >>>>>>>> +static void __enqueue_latency(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) > >>>>>>>> +{ > >>>>>>>> + > >>>>>>>> + /* Only latency sensitive entity can be added to the list */ > >>>>>>>> + if (se->latency_offset >= 0) > >>>>>>>> + return; > >>>>>>>> + > >>>>>>>> + if (!RB_EMPTY_NODE(&se->latency_node)) > >>>>>>>> + return; > >>>>>>>> + > >>>>>>>> + /* > >>>>>>>> + * The entity is always added the latency list at wakeup. > >>>>>>>> + * Then, a not waking up entity that is put back in the list after an > >>>>>>>> + * execution time less than sysctl_sched_min_granularity, means that > >>>>>>>> + * the entity has been preempted by a higher sched class or an entity > >>>>>>>> + * with higher latency constraint. In thi case, the entity is also put > >>>>>>>> + * back in the latency list so it gets a chance to run 1st during the > >>>>>>>> + * next slice. > >>>>>>>> + */ > >>>>>>>> + if (!(flags & ENQUEUE_WAKEUP)) { > >>>>>>>> + u64 delta_exec = se->sum_exec_runtime - se->prev_sum_exec_runtime; > >>>>>>>> + > >>>>>>>> + if (delta_exec >= sysctl_sched_min_granularity) > >>>>>>>> + return; > >>>>>>>> + } > >>>>>>>> + > >>>>>>>> + rb_add_cached(&se->latency_node, &cfs_rq->latency_timeline, __latency_less); > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> +/* > >>>>>>>> + * Dequeue an entity from the latency rb-tree and return true if it was really > >>>>>>>> + * part of the rb-tree: > >>>>>>>> + */ > >>>>>>>> +static bool __dequeue_latency(struct cfs_rq *cfs_rq, struct sched_entity *se) > >>>>>>>> +{ > >>>>>>>> + if (!RB_EMPTY_NODE(&se->latency_node)) { > >>>>>>>> + rb_erase_cached(&se->latency_node, &cfs_rq->latency_timeline); > >>>>>>>> + RB_CLEAR_NODE(&se->latency_node); > >>>>>>>> + return true; > >>>>>>>> + } > >>>>>>>> + > >>>>>>>> + return false; > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> +static struct sched_entity *__pick_first_latency(struct cfs_rq *cfs_rq) > >>>>>>>> +{ > >>>>>>>> + struct rb_node *left = rb_first_cached(&cfs_rq->latency_timeline); > >>>>>>>> + > >>>>>>>> + if (!left) > >>>>>>>> + return NULL; > >>>>>>>> + > >>>>>>>> + return __latency_node_2_se(left); > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> +#ifdef CONFIG_SCHED_DEBUG > >>>>>>>> /************************************************************** > >>>>>>>> * Scheduling class statistics methods: > >>>>>>>> */ > >>>>>>>> @@ -4758,8 +4836,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) > >>>>>>>> check_schedstat_required(); > >>>>>>>> update_stats_enqueue_fair(cfs_rq, se, flags); > >>>>>>>> check_spread(cfs_rq, se); > >>>>>>>> - if (!curr) > >>>>>>>> + if (!curr) { > >>>>>>>> __enqueue_entity(cfs_rq, se); > >>>>>>>> + __enqueue_latency(cfs_rq, se, flags); > >>>>>>>> + } > >>>>>>>> se->on_rq = 1; > >>>>>>>> > >>>>>>>> if (cfs_rq->nr_running == 1) { > >>>>>>>> @@ -4845,8 +4925,10 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) > >>>>>>>> > >>>>>>>> clear_buddies(cfs_rq, se); > >>>>>>>> > >>>>>>>> - if (se != cfs_rq->curr) > >>>>>>>> + if (se != cfs_rq->curr) { > >>>>>>>> __dequeue_entity(cfs_rq, se); > >>>>>>>> + __dequeue_latency(cfs_rq, se); > >>>>>>>> + } > >>>>>>>> se->on_rq = 0; > >>>>>>>> account_entity_dequeue(cfs_rq, se); > >>>>>>>> > >>>>>>>> @@ -4941,6 +5023,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) > >>>>>>>> */ > >>>>>>>> update_stats_wait_end_fair(cfs_rq, se); > >>>>>>>> __dequeue_entity(cfs_rq, se); > >>>>>>>> + __dequeue_latency(cfs_rq, se); > >>>>>>>> update_load_avg(cfs_rq, se, UPDATE_TG); > >>>>>>>> } > >>>>>>>> > >>>>>>>> @@ -4979,7 +5062,7 @@ static struct sched_entity * > >>>>>>>> pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr) > >>>>>>>> { > >>>>>>>> struct sched_entity *left = __pick_first_entity(cfs_rq); > >>>>>>>> - struct sched_entity *se; > >>>>>>>> + struct sched_entity *latency, *se; > >>>>>>>> > >>>>>>>> /* > >>>>>>>> * If curr is set we have to see if its left of the leftmost entity > >>>>>>>> @@ -5021,6 +5104,12 @@ pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr) > >>>>>>>> se = cfs_rq->last; > >>>>>>>> } > >>>>>>>> > >>>>>>>> + /* Check for latency sensitive entity waiting for running */ > >>>>>>>> + latency = __pick_first_latency(cfs_rq); > >>>>>>>> + if (latency && (latency != se) && > >>>>>>>> + wakeup_preempt_entity(latency, se) < 1) > >>>>>>>> + se = latency; > >>>>>>>> + > >>>>>>>> return se; > >>>>>>>> } > >>>>>>>> > >>>>>>>> @@ -5044,6 +5133,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) > >>>>>>>> update_stats_wait_start_fair(cfs_rq, prev); > >>>>>>>> /* Put 'current' back into the tree. */ > >>>>>>>> __enqueue_entity(cfs_rq, prev); > >>>>>>>> + __enqueue_latency(cfs_rq, prev, 0); > >>>>>>>> /* in !on_rq case, update occurred at dequeue */ > >>>>>>>> update_load_avg(cfs_rq, prev, 0); > >>>>>>>> } > >>>>>>>> @@ -12222,6 +12312,7 @@ static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first) > >>>>>>>> void init_cfs_rq(struct cfs_rq *cfs_rq) > >>>>>>>> { > >>>>>>>> cfs_rq->tasks_timeline = RB_ROOT_CACHED; > >>>>>>>> + cfs_rq->latency_timeline = RB_ROOT_CACHED; > >>>>>>>> u64_u32_store(cfs_rq->min_vruntime, (u64)(-(1LL << 20))); > >>>>>>>> #ifdef CONFIG_SMP > >>>>>>>> raw_spin_lock_init(&cfs_rq->removed.lock); > >>>>>>>> @@ -12378,6 +12469,7 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, > >>>>>>>> se->my_q = cfs_rq; > >>>>>>>> > >>>>>>>> se->latency_offset = calc_latency_offset(tg->latency_prio); > >>>>>>>> + RB_CLEAR_NODE(&se->latency_node); > >>>>>>>> > >>>>>>>> /* guarantee group entities always have weight */ > >>>>>>>> update_load_set(&se->load, NICE_0_LOAD); > >>>>>>>> @@ -12529,8 +12621,19 @@ int sched_group_set_latency(struct task_group *tg, int prio) > >>>>>>>> > >>>>>>>> for_each_possible_cpu(i) { > >>>>>>>> struct sched_entity *se = tg->se[i]; > >>>>>>>> + struct rq *rq = cpu_rq(i); > >>>>>>>> + struct rq_flags rf; > >>>>>>>> + bool queued; > >>>>>>>> + > >>>>>>>> + rq_lock_irqsave(rq, &rf); > >>>>>>>> > >>>>>>>> + queued = __dequeue_latency(se->cfs_rq, se); > >>>>>>>> WRITE_ONCE(se->latency_offset, latency_offset); > >>>>>>>> + if (queued) > >>>>>>>> + __enqueue_latency(se->cfs_rq, se, ENQUEUE_WAKEUP); > >>>>>>>> + > >>>>>>>> + > >>>>>>>> + rq_unlock_irqrestore(rq, &rf); > >>>>>>>> } > >>>>>>>> > >>>>>>>> mutex_unlock(&shares_mutex); > >>>>>>>> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > >>>>>>>> index 9a2e71231083..21dd309e98a9 100644 > >>>>>>>> --- a/kernel/sched/sched.h > >>>>>>>> +++ b/kernel/sched/sched.h > >>>>>>>> @@ -570,6 +570,7 @@ struct cfs_rq { > >>>>>>>> #endif > >>>>>>>> > >>>>>>>> struct rb_root_cached tasks_timeline; > >>>>>>>> + struct rb_root_cached latency_timeline; > >>>>>>>> > >>>>>>>> /* > >>>>>>>> * 'curr' points to currently running entity on this cfs_rq. >
