Hi all, Here is v7 of the asymmetric 32-bit support patches that I previously posted here: v1: https://lore.kernel.org/r/20201027215118.27003-1-will@xxxxxxxxxx v2: https://lore.kernel.org/r/20201109213023.15092-1-will@xxxxxxxxxx v3: https://lore.kernel.org/r/20201113093720.21106-1-will@xxxxxxxxxx v4: https://lore.kernel.org/r/20201124155039.13804-1-will@xxxxxxxxxx v5: https://lore.kernel.org/r/20201208132835.6151-1-will@xxxxxxxxxx v6: https://lore.kernel.org/r/20210518094725.7701-1-will@xxxxxxxxxx There was also a nice LWN writeup in case you've forgotten what this is about: https://lwn.net/Articles/838339/ Changes since v6 include: * Bug fix for a pre-existing scheduler migration bug spotted by Valentin (nice work!). I've put this patch at the start. * Prevent execve() of a 32-bit program from a 64-bit deadline task if the forced affinity would violate admission control * Fixed a memory leak and missing rcu_read_lock() spotted by Qais (thanks!) * Handle race between forcing affinity on execve() and CPU hot-unplug * Updated documentation * Introduce task_cpu_possible() macro as suggested by Peter Z * Added some acks/reviewed-by tags, although I didn't include these where patches have changed significantly since last time. Series now based on v5.13-rc3 to avoid conflicting with arm64 cpucaps rework merged at -rc2. Cheers, Will Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Morten Rasmussen <morten.rasmussen@xxxxxxx> Cc: Qais Yousef <qais.yousef@xxxxxxx> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx> Cc: Quentin Perret <qperret@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx> Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx> Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> Cc: kernel-team@xxxxxxxxxxx --->8 Will Deacon (22): sched: Favour predetermined active CPU as migration destination 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 task_struct::user_cpus_ptr to track requested affinity sched: Split the guts of sched_setaffinity() into a helper function sched: Allow task CPU affinity to be restricted on asymmetric systems sched: Introduce task_cpus_dl_admissible() to check proposed affinity freezer: Add frozen_or_skipped() helper function sched: Defer wakeup in ttwu() for unschedulable frozen tasks 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 Documentation: arm64: describe asymmetric 32-bit support .../ABI/testing/sysfs-devices-system-cpu | 9 + .../admin-guide/kernel-parameters.txt | 11 + Documentation/arm64/asymmetric-32bit.rst | 154 ++++++++ Documentation/arm64/index.rst | 1 + arch/arm64/include/asm/cpu.h | 44 ++- arch/arm64/include/asm/cpufeature.h | 8 +- arch/arm64/include/asm/elf.h | 6 +- arch/arm64/include/asm/mmu_context.h | 13 + arch/arm64/kernel/cpufeature.c | 227 ++++++++--- arch/arm64/kernel/cpuinfo.c | 53 +-- arch/arm64/kernel/process.c | 44 ++- arch/arm64/kvm/arm.c | 11 +- arch/arm64/tools/cpucaps | 3 +- include/linux/cpuset.h | 3 +- include/linux/freezer.h | 6 + include/linux/mmu_context.h | 11 + include/linux/sched.h | 21 ++ init/init_task.c | 1 + kernel/cgroup/cpuset.c | 53 ++- kernel/fork.c | 2 + kernel/freezer.c | 10 +- kernel/hung_task.c | 4 +- kernel/sched/core.c | 351 ++++++++++++++---- kernel/sched/sched.h | 1 + 24 files changed, 850 insertions(+), 197 deletions(-) create mode 100644 Documentation/arm64/asymmetric-32bit.rst -- 2.31.1.818.g46aad6cb9e-goog
