From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.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>,
kernel-team@android.com
Subject: [PATCH v5 00/15] An alternative series for asymmetric AArch32 systems
Date: Tue, 8 Dec 2020 13:28:20 +0000 [thread overview]
Message-ID: <20201208132835.6151-1-will@kernel.org> (raw)
Hi all,
Christmas has come early: it's time for version five of these patches
which have previously appeared here:
v1: https://lore.kernel.org/r/20201027215118.27003-1-will@kernel.org
v2: https://lore.kernel.org/r/20201109213023.15092-1-will@kernel.org
v3: https://lore.kernel.org/r/20201113093720.21106-1-will@kernel.org
v4: https://lore.kernel.org/r/20201124155039.13804-1-will@kernel.org
and which started life as a reimplementation of some patches from Qais:
https://lore.kernel.org/r/20201021104611.2744565-1-qais.yousef@arm.com
There's also now a nice writeup on LWN:
https://lwn.net/Articles/838339/
and rumours of a feature film are doing the rounds.
[subscriber-only, but if you're reading this then you should really
subscribe.]
The aim of this series is to allow 32-bit ARM applications to run on
arm64 SoCs where not all of the CPUs support the 32-bit instruction set.
Unfortunately, such SoCs are real and will continue to be productised
over the next few years at least. I can assure you that I'm not just
doing this for fun.
Changes in v5 include:
* Teach cpuset_cpus_allowed() about task_cpu_possible_mask() so that
we can avoid returning incompatible CPUs for a given task. This
means that sched_setaffinity() can be used with larger masks (like
the online mask) from userspace and also allows us to take into
account the cpuset hierarchy when forcefully overriding the affinity
for a task on execve().
* Honour task_cpu_possible_mask() when attaching a task to a cpuset,
so that the resulting affinity mask does not contain any incompatible
CPUs (since it would be rejected by set_cpus_allowed_ptr() otherwise).
* Moved overriding of the affinity mask into the scheduler core rather
than munge affinity masks directly in the architecture backend.
* Extended comments and documentation.
* Some renaming and cosmetic changes.
I'm pretty happy with this now, although it still needs review and will
require rebasing to play nicely with the SCA changes in -next.
Cheers,
Will
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Qais Yousef <qais.yousef@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Quentin Perret <qperret@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: kernel-team@android.com
--->8
Will Deacon (15):
arm64: cpuinfo: Split AArch32 registers out into a separate struct
arm64: Allow mismatched 32-bit EL0 support
KVM: arm64: Kill 32-bit vCPUs on systems with mismatched EL0 support
arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs
arm64: Advertise CPUs capable of running 32-bit applications in sysfs
sched: Introduce task_cpu_possible_mask() to limit fallback rq
selection
cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1
cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()
sched: Reject CPU affinity changes based on task_cpu_possible_mask()
sched: Introduce force_compatible_cpus_allowed_ptr() to limit CPU
affinity
arm64: Implement task_cpu_possible_mask()
arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit
EL0
arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched
system
arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores
.../ABI/testing/sysfs-devices-system-cpu | 9 +
.../admin-guide/kernel-parameters.txt | 8 +
arch/arm64/include/asm/cpu.h | 44 ++--
arch/arm64/include/asm/cpucaps.h | 3 +-
arch/arm64/include/asm/cpufeature.h | 8 +-
arch/arm64/include/asm/mmu_context.h | 13 ++
arch/arm64/kernel/cpufeature.c | 219 ++++++++++++++----
arch/arm64/kernel/cpuinfo.c | 53 +++--
arch/arm64/kernel/process.c | 19 +-
arch/arm64/kvm/arm.c | 11 +-
include/linux/cpuset.h | 3 +-
include/linux/mmu_context.h | 8 +
include/linux/sched.h | 1 +
kernel/cgroup/cpuset.c | 39 ++--
kernel/sched/core.c | 112 +++++++--
15 files changed, 426 insertions(+), 124 deletions(-)
--
2.29.2.576.ga3fc446d84-goog
next reply other threads:[~2020-12-08 13:29 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 13:28 Will Deacon [this message]
2020-12-08 13:28 ` [PATCH v5 01/15] arm64: cpuinfo: Split AArch32 registers out into a separate struct Will Deacon
2020-12-08 13:28 ` [PATCH v5 02/15] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2020-12-08 13:28 ` [PATCH v5 03/15] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2020-12-08 13:28 ` [PATCH v5 04/15] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2020-12-08 13:28 ` [PATCH v5 05/15] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2020-12-08 13:28 ` [PATCH v5 06/15] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon
2020-12-08 13:28 ` [PATCH v5 07/15] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2020-12-17 12:15 ` Qais Yousef
2020-12-17 13:44 ` Peter Zijlstra
2020-12-17 14:59 ` Will Deacon
2020-12-17 15:00 ` Qais Yousef
2020-12-08 13:28 ` [PATCH v5 08/15] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon
2020-12-28 3:54 ` Suren Baghdasaryan
2020-12-08 13:28 ` [PATCH v5 09/15] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon
2020-12-08 13:28 ` [PATCH v5 10/15] sched: Introduce force_compatible_cpus_allowed_ptr() to limit CPU affinity Will Deacon
2020-12-28 4:29 ` Suren Baghdasaryan
2020-12-08 13:28 ` [PATCH v5 11/15] arm64: Implement task_cpu_possible_mask() Will Deacon
2020-12-08 13:28 ` [PATCH v5 12/15] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2020-12-08 13:28 ` [PATCH v5 13/15] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2020-12-08 13:28 ` [PATCH v5 14/15] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2020-12-08 13:28 ` [PATCH v5 15/15] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2020-12-15 17:36 ` [PATCH v5 00/15] An alternative series for asymmetric AArch32 systems Peter Zijlstra
2020-12-15 18:50 ` Will Deacon
2020-12-17 10:55 ` Peter Zijlstra
2020-12-16 11:16 ` Qais Yousef
2020-12-16 14:14 ` Will Deacon
2020-12-16 16:48 ` Qais Yousef
2020-12-16 18:21 ` Suren Baghdasaryan
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