From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qais Yousef <qais.yousef@arm.com>,
Suren Baghdasaryan <surenb@google.com>,
Quentin Perret <qperret@google.com>, Tejun Heo <tj@kernel.org>,
Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
kernel-team@android.com
Subject: Re: [PATCH v6 06/21] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection
Date: Fri, 21 May 2021 18:03:44 +0200 [thread overview]
Message-ID: <20210521160344.GJ5618@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20210518094725.7701-7-will@kernel.org>
On Tue, May 18, 2021 at 10:47:10AM +0100, Will Deacon wrote:
> diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
> index 03dee12d2b61..bc4ac3c525e6 100644
> --- a/include/linux/mmu_context.h
> +++ b/include/linux/mmu_context.h
> @@ -14,4 +14,12 @@
> static inline void leave_mm(int cpu) { }
> #endif
>
> +/*
> + * CPUs that are capable of running task @p. By default, we assume a sane,
> + * homogeneous system. Must contain at least one active CPU.
> + */
> +#ifndef task_cpu_possible_mask
> +# define task_cpu_possible_mask(p) cpu_possible_mask
> +#endif
#ifndef task_cpu_possible_mask
# define task_cpu_possible_mask(p) cpu_possible_mask
# define task_cpu_possible(cpu, p) true
#else
# define task_cpu_possible(cpu, p) cpumask_test_cpu((cpu), task_cpu_possible_mask(p))
#endif
> +
> #endif
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 5226cc26a095..482f7fdca0e8 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1813,8 +1813,11 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
> return cpu_online(cpu);
>
> /* Non kernel threads are not allowed during either online or offline. */
> if (!(p->flags & PF_KTHREAD))
> - return cpu_active(cpu);
+ return cpu_active(cpu) && task_cpu_possible(cpu, p);
> /* KTHREAD_IS_PER_CPU is always allowed. */
> if (kthread_is_per_cpu(p))
Would something like that make sense?
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next prev parent reply other threads:[~2021-05-21 16:05 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 9:47 [PATCH v6 00/21] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon
2021-05-18 9:47 ` [PATCH v6 01/21] arm64: cpuinfo: Split AArch32 registers out into a separate struct Will Deacon
2021-05-21 10:47 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 02/21] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2021-05-21 10:25 ` Catalin Marinas
2021-05-24 12:05 ` Will Deacon
2021-05-24 13:49 ` Catalin Marinas
2021-05-21 10:41 ` Catalin Marinas
2021-05-24 12:09 ` Will Deacon
2021-05-24 13:46 ` Catalin Marinas
2021-05-21 15:22 ` Qais Yousef
2021-05-24 20:21 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 03/21] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2021-05-21 10:47 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 04/21] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2021-05-21 10:55 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 05/21] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2021-05-21 11:00 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 06/21] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon
2021-05-21 16:03 ` Peter Zijlstra [this message]
2021-05-24 12:17 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 07/21] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2021-05-21 17:39 ` Qais Yousef
2021-05-24 20:21 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 08/21] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon
2021-05-21 16:25 ` Qais Yousef
2021-05-24 21:09 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 09/21] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon
2021-05-18 9:47 ` [PATCH v6 10/21] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon
2021-05-18 9:47 ` [PATCH v6 11/21] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon
2021-05-21 16:41 ` Qais Yousef
2021-05-24 21:16 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 12/21] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon
2021-05-21 17:11 ` Qais Yousef
2021-05-24 21:43 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Will Deacon
2021-05-18 10:20 ` Quentin Perret
2021-05-18 10:28 ` Will Deacon
2021-05-18 10:48 ` Quentin Perret
2021-05-18 10:59 ` Will Deacon
2021-05-18 13:19 ` Quentin Perret
2021-05-20 9:13 ` Juri Lelli
2021-05-20 10:16 ` Will Deacon
2021-05-20 10:33 ` Quentin Perret
2021-05-20 12:38 ` Juri Lelli
2021-05-20 12:38 ` Daniel Bristot de Oliveira
2021-05-20 15:06 ` Dietmar Eggemann
2021-05-20 16:00 ` Daniel Bristot de Oliveira
2021-05-20 17:55 ` Dietmar Eggemann
2021-05-20 18:03 ` Will Deacon
2021-05-21 11:26 ` Dietmar Eggemann
2021-05-20 18:01 ` Will Deacon
2021-05-21 5:25 ` Juri Lelli
2021-05-21 8:15 ` Quentin Perret
2021-05-21 8:39 ` Juri Lelli
2021-05-21 10:37 ` Will Deacon
2021-05-21 11:23 ` Dietmar Eggemann
2021-05-21 13:02 ` Quentin Perret
2021-05-21 14:04 ` Juri Lelli
2021-05-21 17:47 ` Dietmar Eggemann
2021-05-21 13:00 ` Daniel Bristot de Oliveira
2021-05-21 13:12 ` Quentin Perret
2021-05-24 20:47 ` Will Deacon
2021-05-18 9:47 ` [PATCH v6 14/21] freezer: Add frozen_or_skipped() helper function Will Deacon
2021-05-18 9:47 ` [PATCH v6 15/21] sched: Defer wakeup in ttwu() for unschedulable frozen tasks Will Deacon
2021-05-18 9:47 ` [PATCH v6 16/21] arm64: Implement task_cpu_possible_mask() Will Deacon
2021-05-24 14:57 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 17/21] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2021-05-24 15:02 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 18/21] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2021-05-24 15:46 ` Catalin Marinas
2021-05-24 20:32 ` Will Deacon
2021-05-25 9:43 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 19/21] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2021-05-24 15:47 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 20/21] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2021-05-24 15:47 ` Catalin Marinas
2021-05-18 9:47 ` [PATCH v6 21/21] Documentation: arm64: describe asymmetric 32-bit support Will Deacon
2021-05-21 17:37 ` Qais Yousef
2021-05-24 21:46 ` Will Deacon
2021-05-24 16:22 ` Catalin Marinas
2021-05-21 17:45 ` [PATCH v6 00/21] Add support for 32-bit tasks on asymmetric AArch32 systems Qais Yousef
2021-05-24 22:08 ` Will Deacon
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