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    SubjectRe: [PATCH v8 2/3] watchdog: add watchdog_cpumask sysctl to assist nohz
    ----- Original Message -----
    From: "Chris Metcalf" <cmetcalf@ezchip.com>
    [...]
    > On 04/22/2015 04:20 AM, Ulrich Obergfell wrote:
    >> Chris,
    >>
    >> in principle the change looks o.k. to me, even though I'm not really familiar
    >> with the watchdog_nmi_disable_all() and watchdog_nmi_enable_all() functions.
    >> It is my understanding that those functions are only called once via 'initcall'
    >> early during kernel startup as shown in the following flow of execution:
    >>
    >> [...]
    >> It seems crucial that lockup_detector_init() is executed before fixup_ht_bug().
    >
    > Uli, thanks for doing the follow-up analysis. I didn't know
    > about the fixup_ht_bug() path, but as you show, it seems to be OK.
    >
    > We could think about doing some kind of additional paranoia here,
    > like a wrapper around &watchdog_cpumask that checks some additional
    > boolean that says whether it's been properly initialized or not.
    >
    > But I think it's probably OK to leave it as-is; we already had the
    > potential of issues if any watchdog code was invoked prior to
    > init_watchdog(), for example due to the sample period being unset.
    >
    > What do you think?

    Chris,

    I also think it's probably OK to leave it as-is, in particular because
    you indicated in http://marc.info/?l=linux-kernel&m=143016646903545&w=2
    that you are going to make watchdog_cpumask static instead of allocating
    it dynamically.

    Regards,

    Uli


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