From: Will Deacon <will@kernel.org>
To: Peter Zijlstra <peterz@infradead.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>,
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>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
kernel-team@android.com
Subject: Re: [PATCH v7 13/22] sched: Allow task CPU affinity to be restricted on asymmetric systems
Date: Wed, 26 May 2021 17:35:25 +0100 [thread overview]
Message-ID: <20210526163523.GA19758@willie-the-truck> (raw)
In-Reply-To: <YK51SSUvL2psb3OL@hirez.programming.kicks-ass.net>
On Wed, May 26, 2021 at 06:20:25PM +0200, Peter Zijlstra wrote:
> On Tue, May 25, 2021 at 04:14:23PM +0100, Will Deacon wrote:
> > +static int restrict_cpus_allowed_ptr(struct task_struct *p,
> > + struct cpumask *new_mask,
> > + const struct cpumask *subset_mask)
> > +{
> > + struct rq_flags rf;
> > + struct rq *rq;
> > + int err;
> > + struct cpumask *user_mask = NULL;
> > +
> > + if (!p->user_cpus_ptr) {
> > + user_mask = kmalloc(cpumask_size(), GFP_KERNEL);
>
> if (!user_mask)
> return -ENOMEM;
> }
>
> ?
We won't blow up if we continue without user_mask here, but I agree that
it's more straightforward to return an error and have
force_compatible_cpus_allowed_ptr() noisily override the mask.
We're in pretty deep trouble if we're failing this allocation anyway.
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will@kernel.org>
To: Peter Zijlstra <peterz@infradead.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>,
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>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
kernel-team@android.com
Subject: Re: [PATCH v7 13/22] sched: Allow task CPU affinity to be restricted on asymmetric systems
Date: Wed, 26 May 2021 17:35:25 +0100 [thread overview]
Message-ID: <20210526163523.GA19758@willie-the-truck> (raw)
In-Reply-To: <YK51SSUvL2psb3OL@hirez.programming.kicks-ass.net>
On Wed, May 26, 2021 at 06:20:25PM +0200, Peter Zijlstra wrote:
> On Tue, May 25, 2021 at 04:14:23PM +0100, Will Deacon wrote:
> > +static int restrict_cpus_allowed_ptr(struct task_struct *p,
> > + struct cpumask *new_mask,
> > + const struct cpumask *subset_mask)
> > +{
> > + struct rq_flags rf;
> > + struct rq *rq;
> > + int err;
> > + struct cpumask *user_mask = NULL;
> > +
> > + if (!p->user_cpus_ptr) {
> > + user_mask = kmalloc(cpumask_size(), GFP_KERNEL);
>
> if (!user_mask)
> return -ENOMEM;
> }
>
> ?
We won't blow up if we continue without user_mask here, but I agree that
it's more straightforward to return an error and have
force_compatible_cpus_allowed_ptr() noisily override the mask.
We're in pretty deep trouble if we're failing this allocation anyway.
Will
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next prev parent reply other threads:[~2021-05-26 16:35 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 15:14 [PATCH v7 00/22] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 01/22] sched: Favour predetermined active CPU as migration destination Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-26 11:14 ` Valentin Schneider
2021-05-26 11:14 ` Valentin Schneider
2021-05-26 12:32 ` Peter Zijlstra
2021-05-26 12:32 ` Peter Zijlstra
2021-05-26 12:36 ` Valentin Schneider
2021-05-26 12:36 ` Valentin Schneider
2021-05-26 16:03 ` Will Deacon
2021-05-26 16:03 ` Will Deacon
2021-05-26 17:46 ` Valentin Schneider
2021-05-26 17:46 ` Valentin Schneider
2021-05-25 15:14 ` [PATCH v7 02/22] arm64: cpuinfo: Split AArch32 registers out into a separate struct Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 03/22] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 04/22] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 05/22] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 06/22] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 07/22] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 08/22] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-26 15:02 ` Peter Zijlstra
2021-05-26 15:02 ` Peter Zijlstra
2021-05-26 16:07 ` Will Deacon
2021-05-26 16:07 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 09/22] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 10/22] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-26 15:15 ` Peter Zijlstra
2021-05-26 15:15 ` Peter Zijlstra
2021-05-26 16:12 ` Will Deacon
2021-05-26 16:12 ` Will Deacon
2021-05-26 17:56 ` Peter Zijlstra
2021-05-26 17:56 ` Peter Zijlstra
2021-05-26 18:59 ` Will Deacon
2021-05-26 18:59 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 11/22] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 12/22] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 13/22] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-26 16:20 ` Peter Zijlstra
2021-05-26 16:20 ` Peter Zijlstra
2021-05-26 16:35 ` Will Deacon [this message]
2021-05-26 16:35 ` Will Deacon
2021-05-26 16:30 ` Peter Zijlstra
2021-05-26 16:30 ` Peter Zijlstra
2021-05-26 17:02 ` Will Deacon
2021-05-26 17:02 ` Will Deacon
2021-05-27 7:56 ` Peter Zijlstra
2021-05-27 7:56 ` Peter Zijlstra
2021-05-25 15:14 ` [PATCH v7 14/22] sched: Introduce task_cpus_dl_admissible() to check proposed affinity Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 15/22] freezer: Add frozen_or_skipped() helper function Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 16/22] sched: Defer wakeup in ttwu() for unschedulable frozen tasks Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-27 14:10 ` Peter Zijlstra
2021-05-27 14:10 ` Peter Zijlstra
2021-05-27 14:31 ` Peter Zijlstra
2021-05-27 14:31 ` Peter Zijlstra
2021-05-27 14:44 ` Will Deacon
2021-05-27 14:44 ` Will Deacon
2021-05-27 14:55 ` Peter Zijlstra
2021-05-27 14:55 ` Peter Zijlstra
2021-05-27 14:50 ` Peter Zijlstra
2021-05-27 14:50 ` Peter Zijlstra
2021-05-28 10:49 ` Peter Zijlstra
2021-05-28 10:49 ` Peter Zijlstra
2021-05-27 14:36 ` Will Deacon
2021-05-27 14:36 ` Will Deacon
2021-06-01 8:21 ` [RFC][PATCH] freezer,sched: Rewrite core freezer logic Peter Zijlstra
2021-06-01 8:21 ` Peter Zijlstra
2021-06-01 11:27 ` Peter Zijlstra
2021-06-01 11:27 ` Peter Zijlstra
2021-06-02 12:54 ` Will Deacon
2021-06-02 12:54 ` Will Deacon
2021-06-03 10:35 ` Peter Zijlstra
2021-06-03 10:35 ` Peter Zijlstra
2021-06-03 10:58 ` Will Deacon
2021-06-03 10:58 ` Will Deacon
2021-06-03 11:26 ` Peter Zijlstra
2021-06-03 11:26 ` Peter Zijlstra
2021-06-03 11:36 ` Will Deacon
2021-06-03 11:36 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 17/22] arm64: Implement task_cpu_possible_mask() Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 18/22] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 19/22] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 20/22] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 21/22] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 15:14 ` [PATCH v7 22/22] Documentation: arm64: describe asymmetric 32-bit support Will Deacon
2021-05-25 15:14 ` Will Deacon
2021-05-25 17:13 ` Marc Zyngier
2021-05-25 17:13 ` Marc Zyngier
2021-05-25 17:27 ` Will Deacon
2021-05-25 17:27 ` Will Deacon
2021-05-25 18:11 ` Marc Zyngier
2021-05-25 18:11 ` Marc Zyngier
2021-05-26 16:00 ` Will Deacon
2021-05-26 16:00 ` Will Deacon
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