[lkml]   [2010]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [RFC PATCH 1/2] mac80211: make max_network_latency notifier atomic safe
    On Wed, 09 Jun 2010 11:38:07 +0200
    Johannes Berg <> wrote:

    > On Wed, 2010-06-09 at 11:15 +0200, wrote:
    > > In order to have the pm_qos framework be callable from interrupt
    > > context, all listeners have to also be callable in that context.
    > That makes no sense at all. Why add work structs _everywhere_ in the
    > callees and make the API harder to use and easy to get wrong completely,
    > instead of just adding a single work struct that will be queued from the
    > caller and dealing with the locking complexity etc. just once.
    > johannes

    Just to defend this approach, but I'm certainly not married to it
    (hence RFC):

    There are only two listeners at the moment. I suspect that most future
    uses of the framework need to be atomic, as the driver that
    requests a specific quality of service probably doesn't want to get into
    races with the provider of that service(listener). So i suspected the
    network listener to be the special case.

    The race between service-provider and qos-requester for non-atomic
    contextes is already there, isn't it? so, locking complexity shouldn't
    be worse than before.

    But my first approach to this is seen here:

    A third possibility would be to make it dependent on the
    type of the constraint, if blocking notifiers are allowed or not.
    But that would sacrifice API consistency (update_request for one
    constraint is allowed to be called in interrupt context and
    update_request for another would be not).


     \ /
      Last update: 2010-06-09 12:23    [W:0.019 / U:11.188 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site