From: Tejun Heo <tj@kernel.org> mainline inclusion from mainline-v6.19-rc1 commit a9c1fbbd6dadbaa38c157a07d5d11005460b86b9 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- When a sched_ext scheduler tries to kick a CPU, the CPU may be running a higher class task. sched_ext has no control over such CPUs. A sched_ext scheduler couldn't have expected to get access to the CPU after kicking it anyway. Skip kicking when the target CPU is running a higher class. Reviewed-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Signed-off-by: cheliequan <cheliequan@inspur.com> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/sched/ext.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 2f1637b17b2b..97929e3fbadc 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -5704,18 +5704,23 @@ static bool kick_one_cpu(s32 cpu, struct rq *this_rq, unsigned long *pseqs) { struct rq *rq = cpu_rq(cpu); struct scx_rq *this_scx = &this_rq->scx; + const struct sched_class *cur_class; bool should_wait = false; unsigned long flags; raw_spin_rq_lock_irqsave(rq, flags); + cur_class = rq->curr->sched_class; /* * During CPU hotplug, a CPU may depend on kicking itself to make - * forward progress. Allow kicking self regardless of online state. + * forward progress. Allow kicking self regardless of online state. If + * @cpu is running a higher class task, we have no control over @cpu. + * Skip kicking. */ - if (cpu_online(cpu) || cpu == cpu_of(this_rq)) { + if ((cpu_online(cpu) || cpu == cpu_of(this_rq)) && + !sched_class_above(cur_class, &ext_sched_class)) { if (cpumask_test_cpu(cpu, this_scx->cpus_to_preempt)) { - if (rq->curr->sched_class == &ext_sched_class) + if (cur_class == &ext_sched_class) rq->curr->scx.slice = 0; cpumask_clear_cpu(cpu, this_scx->cpus_to_preempt); } -- 2.34.1