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    SubjectRe: [PATCH v5 7/9] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu()
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    On Mon, Nov 23 2020 at 17:58, Alex Belits wrote:
    > From: Yuri Norov <ynorov@marvell.com>
    >
    > For nohz_full CPUs the desirable behavior is to receive interrupts
    > generated by tick_nohz_full_kick_cpu(). But for hard isolation it's
    > obviously not desirable because it breaks isolation.
    >
    > This patch adds check for it.

    git grep 'This patch' Documentation/process/

    > */
    > void tick_nohz_full_kick_cpu(int cpu)
    > {
    > - if (!tick_nohz_full_cpu(cpu))
    > + smp_rmb();

    Undocumented smp_rmb() ...

    > + if (!tick_nohz_full_cpu(cpu) || task_isolation_on_cpu(cpu))
    > return;

    I still have to see a convincing argument why task isolation is special
    and not just a straight forward extension of NOHZ full cpu isolation.

    It's not special as much as you want it to be special.

    Thanks,

    tglx

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