On Mon, Jul 23, 2018 at 01:39:30PM +0800, Chen Lin wrote:
> From: Chen Lin <cheng.lin...@zte.com.cn>
>
> NUMA balancing has not taken *isolcpus(isolated cpus)* into
> consideration. It may migrate tasks onto isolated cpus and the
> migrated tasks will never escape from the isolated cpus, which will
> break the isolation provided by *isolcpus* boot parameter and
> intrduce various problems.
>
> This patch ensure NUMA balancing not to balance tasks onto iaolated
> cpus.
I'm not sure what kernel you're patching, but cpu_isolated_map doesn't
exist anymore. Also, if it steps on isolated CPUs, this is the wrong fix
anyway. Load-balancing should be constrained to the current root domain.
> Signed-off-by: Cheng Lin <cheng.lin...@zte.com.cn>
> Signed-off-by: Tan Hu <tan...@zte.com.cn>
> Signed-off-by: Jiang Biao <jiang.bi...@zte.com.cn>
This SoB chain is invalid.
> ---
> kernel/sched/core.c | 9 ++++++---
> kernel/sched/fair.c | 3 ++-
> 2 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index fe365c9..f9ce90c 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1302,10 +1302,12 @@ int migrate_swap(struct task_struct *cur, struct
> task_struct *p)
> if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu))
> goto out;
>
> - if (!cpumask_test_cpu(arg.dst_cpu, &arg.src_task->cpus_allowed))
> + if ((!cpumask_test_cpu(arg.dst_cpu, &arg.src_task->cpus_allowed))
> + || cpumask_test_cpu(arg.dst_cpu, cpu_isolated_map))
> goto out;
>
> - if (!cpumask_test_cpu(arg.src_cpu, &arg.dst_task->cpus_allowed))
> + if ((!cpumask_test_cpu(arg.src_cpu, &arg.dst_task->cpus_allowed))
> + || cpumask_test_cpu(arg.src_cpu, cpu_isolated_map))
> goto out;
>
> trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu);
> @@ -5508,7 +5510,8 @@ int migrate_task_to(struct task_struct *p, int
> target_cpu)
> if (curr_cpu == target_cpu)
> return 0;
>
> - if (!cpumask_test_cpu(target_cpu, &p->cpus_allowed))
> + if ((!cpumask_test_cpu(target_cpu, &p->cpus_allowed))
> + || cpumask_test_cpu(target_cpu, cpu_isolated_map))
> return -EINVAL;
>
> /* TODO: This is not properly updating schedstats */
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 2f0a0be..a91f8fe 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -1724,7 +1724,8 @@ static void task_numa_find_cpu(struct task_numa_env
> *env,
>
> for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
> /* Skip this CPU if the source task cannot migrate */
> - if (!cpumask_test_cpu(cpu, &env->p->cpus_allowed))
> + if ((!cpumask_test_cpu(cpu, &env->p->cpus_allowed))
> + || cpumask_test_cpu(cpu, cpu_isolated_map))
> continue;
>
> env->dst_cpu = cpu;
> --
> 1.8.3.1
>
