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    SubjectRe: [PATCH] protect migration/%d etc from sched_setaffinity
    > On Thu, 2003-07-31 at 15:46, Joe Korty wrote:
    >
    > > Lock out users from changing the cpu affinity of those per-cpu system
    > > daemons which cannot survive such a change, such as migration/%d.
    > >
    > > Passes basic handtest of sched_setaffinity(2) on various locked and
    > > unlocked processes on a i386, otherwise untested except by eyeball.
    > >
    > > Except for one line in i386, no arch needed any changes to support
    > > this patch.
    >
    > I have been wondering what to do about processor affinity and kernel
    > threads. I just concluded "only root can change it, and we can let root
    > stab herself if she really wants to."
    >
    > But if this is really an issue, why not just do:
    >
    > ret = -EINVAL;
    > if (!p->mm)
    > goto out_unlock;
    >
    > in sys_sched_setaffinity ?
    >
    > Robert Love


    It's not all system daemons, just some of them that need protection.

    Keeping the set of locked-down daemons to the smallest possible is
    important when one wants to 'set aside' cpus for use only by
    specific, need-the-lowest-latency-possible realtime applications.

    Joe
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