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Diffstat (limited to 'Documentation/arch/arm64/asymmetric-32bit.rst')
| -rw-r--r-- | Documentation/arch/arm64/asymmetric-32bit.rst | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/arch/arm64/asymmetric-32bit.rst b/Documentation/arch/arm64/asymmetric-32bit.rst index 64a0b505da7d..57b8d7476f71 100644 --- a/Documentation/arch/arm64/asymmetric-32bit.rst +++ b/Documentation/arch/arm64/asymmetric-32bit.rst @@ -55,7 +55,7 @@ sysfs The subset of CPUs capable of running 32-bit tasks is described in ``/sys/devices/system/cpu/aarch32_el0`` and is documented further in -``Documentation/ABI/testing/sysfs-devices-system-cpu``. +Documentation/ABI/testing/sysfs-devices-system-cpu. **Note:** CPUs are advertised by this file as they are detected and so late-onlining of 32-bit-capable CPUs can result in the file contents @@ -153,3 +153,11 @@ asymmetric system, a broken guest at EL1 could still attempt to execute mode will return to host userspace with an ``exit_reason`` of ``KVM_EXIT_FAIL_ENTRY`` and will remain non-runnable until successfully re-initialised by a subsequent ``KVM_ARM_VCPU_INIT`` operation. + +NOHZ FULL +--------- + +To avoid perturbing an adaptive-ticks CPU (specified using +``nohz_full=``) when a 32-bit task is forcefully migrated, these CPUs +are treated as 64-bit-only when support for asymmetric 32-bit systems +is enabled. |