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    SubjectRe: [RFC][PATCH 6/8] mm: handle_speculative_fault()
    On Fri, 8 Jan 2010, Linus Torvalds wrote:

    > I bet it won't be a problem. It's when things go cross-socket that they
    > suck. So 16 cpu's across two sockets I wouldn't worry about.
    > > > Because let's face it - if your workload does several million page faults
    > > > per second, you're just doing something fundamentally _wrong_.
    > >
    > > You may just want to get your app running and its trying to initialize
    > > its memory in parallel on all threads. Nothing wrong with that.
    > Umm. That's going to be limited by the memset/memcpy, not the rwlock, I
    > bet.

    That may be true for a system with 2 threads. As the number of threads
    increases so does the cacheline contention. In larger systems the
    memset/memcpy is negligible.

    > The benchmark in question literally did a single byte write to each page
    > in order to show just the kernel component. That really isn't realistic
    > for any real load.

    Each anon fault also includes zeroing the page before its ready to be
    written to. The cachelines will be hot after a fault and initialization of
    any variables in the page will be fast due to that warming up effect.

     \ /
      Last update: 2010-01-08 19:37    [W:0.026 / U:1.056 seconds]
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