linux-kernel - [PATCH 0/3] sched, x86, arm64: PREEMPT

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Message-Id: <20210722175157.1367122-1-valentin.schneider@arm.com>
Date:   Thu, 22 Jul 2021 18:51:54 +0100
From:   Valentin Schneider <valentin.schneider@....com>
To:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-rt-users@...r.kernel.org, x86@...nel.org
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Steven Rostedt <rostedt@...dmis.org>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, Mark Brown <broonie@...nel.org>,
        Dave Martin <Dave.Martin@....com>,
        Ard Biesheuvel <ardb@...nel.org>
Subject: [PATCH 0/3] sched, x86, arm64: PREEMPT_RT, FPU and preemption

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(-)

--
2.25.1