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    SubjectRe: [RFC 00/12] locking: Separate lock tracepoints from lockdep/lock_stat (v1)
    On Wed, Feb 9, 2022 at 1:09 AM Peter Zijlstra <peterz@infradead.org> wrote:
    >
    > On Tue, Feb 08, 2022 at 10:41:56AM -0800, Namhyung Kim wrote:
    >
    > > Eventually I'm mostly interested in the contended locks only and I
    > > want to reduce the overhead in the fast path. By moving that, it'd be
    > > easy to track contended locks with timing by using two tracepoints.
    >
    > So why not put in two new tracepoints and call it a day?
    >
    > Why muck about with all that lockdep stuff just to preserve the name
    > (and in the process continue to blow up data structures etc..). This
    > leaves distros in a bind, will they enable this config and provide
    > tracepoints while bloating the data structures and destroying things
    > like lockref (which relies on sizeof(spinlock_t)), or not provide this
    > at all.

    If it's only lockref, is it possible to change it to use arch_spinlock_t
    so that it can remain in 4 bytes? It'd be really nice if we can keep
    spin lock size, but it'd be easier to carry the name with it for
    analysis IMHO.

    Thanks,
    Namhyung

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