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    SubjectRe: [PATCH] cpumask: fix lg_lock/br_lock.

    * Andrew Morton <akpm@linux-foundation.org> wrote:

    > On Tue, 28 Feb 2012 09:43:59 +0100
    > Ingo Molnar <mingo@elte.hu> wrote:
    >
    > > This patch should also probably go upstream through the
    > > locking/lockdep tree? Mind sending it us once you think it's
    > > ready?
    >
    > Oh goody, that means you own
    > http://marc.info/?l=linux-kernel&m=131419353511653&w=2.
    >
    > I do think the brlock code is sick, but Nick has turned into
    > an ex-Nick and nobody works on it.

    The main problem, highlighted by the above soft lockup report,
    is that lglocks and brlocks go outside the regular spinlock
    facilities and thus avoid quite a bit of generic lock debugging
    for no good reason. Those patches should never have gone
    upstream in their incomplete form via the VFS tree.

    As part of any cleanup they should first be converted from
    arch_spinlock_t to regular spinlock_t - I bet if that is done
    then that not only simplifies the wrappers massively, it also
    turns the above soft lockup report into a nice, actionable
    lockdep splat.

    Andi's deficient patch does not address that main shortcoming of
    brlocks/lglocks, it just addresses a symptom - while introducing
    a handful of new symptoms of suckage.

    I'll review and process resubmitted patches from Andi if he
    wants to submit a proper, complete series - but there's a
    quality threshold and in this case I'd rather keep 1970's
    preprocessor code that sucks very visibly and possibly attracts
    someone with a clue than have a sloppy patch hiding the deeper
    design problems done by a clueless person who is also openly
    hostile towards the concept of producing quality code.

    Thanks,

    Ingo


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