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. 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? >> 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.
