On Wed, Apr 24, 2019 at 12:18 AM Vineeth Remanan Pillai <vpil...@digitalocean.com> wrote: > > Second iteration of the core-scheduling feature. > > This version fixes apparent bugs and performance issues in v1. This > doesn't fully address the issue of core sharing between processes > with different tags. Core sharing still happens 1% to 5% of the time > based on the nature of workload and timing of the runnable processes. > > Changes in v2 > ------------- > - rebased on mainline commit: 6d906f99817951e2257d577656899da02bb33105 > - Fixes for couple of NULL pointer dereference crashes > - Subhra Mazumdar > - Tim Chen
Is this one missed? Or fixed with a better impl? The boot up CPUs don't match the possible cpu map, so the not onlined CPU rq->core are not initialized, which causes NULL pointer dereference panic in online_fair_sched_group(): Thanks, -Aubrey diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 85c728d..bdabf20 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10492,6 +10492,10 @@ void online_fair_sched_group(struct task_group *tg) rq = cpu_rq(i); se = tg->se[i]; +#ifdef CONFIG_SCHED_CORE + if (!rq->core) + continue; +#endif raw_spin_lock_irq(rq_lockp(rq)); update_rq_clock(rq); attach_entity_cfs_rq(se); > - Improves priority comparison logic for process in different cpus > - Peter Zijlstra > - Aaron Lu > - Fixes a hard lockup in rq locking > - Vineeth Pillai > - Julien Desfossez > - Fixes a performance issue seen on IO heavy workloads > - Vineeth Pillai > - Julien Desfossez > - Fix for 32bit build > - Aubrey Li > > Issues > ------ > - Processes with different tags can still share the core > - A crash when disabling cpus with core-scheduling on > - https://paste.debian.net/plainh/fa6bcfa8 > > --- > > Peter Zijlstra (16): > stop_machine: Fix stop_cpus_in_progress ordering > sched: Fix kerneldoc comment for ia64_set_curr_task > sched: Wrap rq::lock access > sched/{rt,deadline}: Fix set_next_task vs pick_next_task > sched: Add task_struct pointer to sched_class::set_curr_task > sched/fair: Export newidle_balance() > sched: Allow put_prev_task() to drop rq->lock > sched: Rework pick_next_task() slow-path > sched: Introduce sched_class::pick_task() > sched: Core-wide rq->lock > sched: Basic tracking of matching tasks > sched: A quick and dirty cgroup tagging interface > sched: Add core wide task selection and scheduling. > sched/fair: Add a few assertions > sched: Trivial forced-newidle balancer > sched: Debug bits... > > Vineeth Remanan Pillai (1): > sched: Wake up sibling if it has something to run > > include/linux/sched.h | 9 +- > kernel/Kconfig.preempt | 7 +- > kernel/sched/core.c | 800 +++++++++++++++++++++++++++++++++++++-- > kernel/sched/cpuacct.c | 12 +- > kernel/sched/deadline.c | 99 +++-- > kernel/sched/debug.c | 4 +- > kernel/sched/fair.c | 137 +++++-- > kernel/sched/idle.c | 42 +- > kernel/sched/pelt.h | 2 +- > kernel/sched/rt.c | 96 +++-- > kernel/sched/sched.h | 185 ++++++--- > kernel/sched/stop_task.c | 35 +- > kernel/sched/topology.c | 4 +- > kernel/stop_machine.c | 2 + > 14 files changed, 1145 insertions(+), 289 deletions(-) > > -- > 2.17.1 >