lkml.org 
[lkml]   [2010]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [linux-pm] [PATCH 0/8] Suspend block api (version 8)
    On Mon, May 31, 2010 at 04:26:17PM -0700, mark gross wrote:
    > On Mon, May 31, 2010 at 11:38:55PM +0200, Rafael J. Wysocki wrote:
    > > On Monday 31 May 2010, Arve Hjønnevåg wrote:
    > > > 2010/5/29 Alan Stern <stern@rowland.harvard.edu>:
    > > > > On Sat, 29 May 2010, Arve Hjønnevåg wrote:
    > > > >
    > > > >> > In place of in-kernel suspend blockers, there will be a new type of QoS
    > > > >> > constraint -- call it QOS_EVENTUALLY. It's a very weak constraint,
    > > > >> > compatible with all cpuidle modes in which runnable threads are allowed
    > > > >> > to run (which is all of them), but not compatible with suspend.
    > > > >> >
    > > > >> This sound just like another API rename. It will work, but given that
    > > > >> suspend blockers was the name least objectionable last time around,
    > > > >> I'm not sure what this would solve.
    > > > >
    > > > > It's not just a rename. By changing this into a QoS constraint, we
    > > > > make it more generally useful. Instead of standing on its own, it
    > > > > becomes part of the PM-QOS framework.
    > > > >
    > > >
    > > > We cannot use the existing pm-qos framework. It is not safe to call
    > > > from atomic context.
    > >
    > > We've just merged a patch that fixed that if I'm not mistaken. Mark, did your
    > > PM QoS update fix that?
    > >
    >
    > I'm pretty sure it can be called in atomic context, and if its not I'm
    > sure we can fix that. It can be called in atomic context. I don't
    > think it was ever a problem to call it in atomic context. The problem it
    > had was that crappy list of string compares. Thats been fixed.
    >

    um, the notifiers that are currently used may not be cool in atomic
    context :(

    --mgross



    > --mgross
    >
    > > > Also, it does not have any state constraints, so it iterates over every
    > > > registered constraint each time one of them changes.
    > >
    > > That's fixable IMO.
    > >
    > > > Nor does is currently provide any stats for debugging.
    > >
    > > That's why Alan is proposing to add that.
    > >
    > > > The original wakelock patchset supported a wakelock type so it could
    > > > be used to block more then suspend, but I had to remove this because
    > > > it "overlapped" with pm-qos. So, yes I do consider this just another
    > > > rename.
    > >
    > > It's an extension of an existing framework rather than an addition of a new
    > > one, with entirely new API and so on. Extending existing APIs is much
    > > preferred to adding new ones, in general.
    > >
    > > Rafael
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2010-06-01 15:49    [W:0.031 / U:31.292 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site