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    SubjectRe: [patch 0/5] lightweight robust futexes: -V1
    On Thu, Feb 16, 2006, Ingo Molnar wrote:
    >
    > * Johannes Stezenbach <js@linuxtv.org> wrote:
    >
    > > Anyway: If a process can trash its robust futext list and then die
    > > with a segfault, why are the futexes still robust? In this case the
    > > kernel has no way to wake up waiters with FUTEX_OWNER_DEAD, or does
    > > it?
    >
    > that's memory corruption - which robust futexes do not (and cannot)
    > solve. Robustness is mostly about handling sudden death (e.g. which is
    > due to oom, or is due to a user killing the task, or due to the
    > application crashing in some non-memory-corrupting way), but it cannot
    > handle all possible failure modes.

    Hm, OK, from reading this and the other threads on this
    topic I get:

    - there is a tradeoff between speed and robustness
    - the focus for "robust futexes" is on speed
    (else they wouldn't deserve to be called futexes)
    - thus it is acceptable if they are just 99% robust

    That's OK, but IMHO it wouldn't hurt to clearly spell
    it out in the documentation.


    However, this leaves the question: Is there a slower, but 100% robust
    alternative on Linux for applications which need it?


    Johannes
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