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    SubjectRe: idr_get_new_exact ?
    On Mon, 20 Sep 2010 16:11:31 +0200
    Ohad Ben-Cohen <ohad@wizery.com> wrote:

    > Occasionally, drivers care about the value that idr associates with
    > their pointers.
    >
    > Today we have idr_get_new_above() which allocates a new idr entry
    > above or equal to a given starting id, but sometimes drivers need to
    > force an exact value.
    >
    > To overcome this small API gap, drivers are wrapping idr_get_new_above
    > and then either BUG_ON() or just call idr_remove() and returns -EBUSY
    > when idr allocates them an id which is different than their requested
    > value.
    >
    > There are only a handful of users who need this (see below. especially
    > note the i2c comment :), but it might be nice to have such an API (a
    > bit less of code, and a bit less error prone).
    >
    > Would something like the below be desirable/acceptable ?

    It seems OK to me - it's an improvement over what we have now.

    > (untested. and i just picked the simplest and straight-forward way to
    > implement this; obviously it's not optimal since there's no reason to
    > even allocate an id if we know it's not the id we're looking for. but
    > it's enough to get the idea, it's not a hot path, and it's what
    > drivers are doing today)

    Sure, we can speed it up later if that appears to be necessary.



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