[PATCH 0/3] sched, x86, arm64: PREEMPT_RT, FPU and preemption

From: Valentin Schneider
Date: Thu Jul 22 2021 - 13:53:05 EST


Hi folks,

This stems from some more v5.13-rt1 breakage on arm64. This time per-CPU access
safety isn't sufficient, we really need to keep preemption disabled.

In a happy accident I stumbled on

cba08c5dc6dc ("x86/fpu: Make kernel FPU protection RT friendly")

so I packaged what was done there into some common helpers and plastered them
over the problematic areas.

Cheers,
Valentin

Valentin Schneider (3):
sched/preempt: Introduce preempt_{enable, disable}_bh()
x86/fpu: Make FPU protection reuse common helper
arm64/fpsimd: Fix FPSIMD context handling vs PREEMPT_RT

arch/arm64/kernel/fpsimd.c | 6 ++++--
arch/x86/include/asm/fpu/api.h | 19 ++-----------------
include/linux/bottom_half.h | 26 ++++++++++++++++++++++++++
3 files changed, 32 insertions(+), 19 deletions(-)

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2.25.1