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    SubjectRe: [Problem] Cache line starvation
    On Fri, 21 Sep 2018, Peter Zijlstra wrote:
    > On Fri, Sep 21, 2018 at 02:02:26PM +0200, Sebastian Andrzej Siewior wrote:
    > > We reproducibly observe cache line starvation on a Core2Duo E6850 (2
    > > cores), a i5-6400 SKL (4 cores) and on a NXP LS2044A ARM Cortex-A72 (4
    > > cores).
    > >
    > > The problem can be triggered with a v4.9-RT kernel by starting
    >
    > > Daniel reported that disabling ticket locks on 4.4 makes the problem go
    > > away, but he hasn't run a long time test yet and as we saw with 4.14 it can
    > > take quite a while.
    >
    > On 4.4 and 4.9 ARM64 still uses ticket locks. So I'm very interested to
    > know if the ticket locks on x86 really fix or just make it harder.

    We can run 4.4. with ticket locks over the weekend.

    Thanks,

    tglx

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