[lkml]   [2002]   [Jan]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [2.4.17/18pre] VM and swap - it's really unusable
    On Tue, 8 Jan 2002, Andrew Morton wrote:

    > > What a preemptible kernel can do that a non-preemptible kernel can't is:
    > > reschedule exactly as often as necessary, instead of having lots of extra
    > > schedule points inserted all over the place, firing when *they* think the
    > > time is right, which may well be earlier than necessary.
    > Nope. `if (current->need_resched)' -> the time is right (beyond right,
    > actually).

    Have we ever considered making rescheduling work like get_user? That is,
    make current->need_resched be a pointer, and if we need to reschedule,
    make it an INVALID pointer that causes us to fault and call schedule in
    its fault path?

    Orthogonally, for rescheduling points with locks, we could build a version
    of the spinlocks that know when they're blocking other processes and can
    do a spin_yield(&lock) in places where they can safely give up a lock. On
    single processor, spin_yield could translate to a scheduling point.

    "Love the dolphins," she advised him. "Write by W.A.S.T.E.."

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:15    [W:0.021 / U:11.336 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site