lkml.org 
[lkml]   [2010]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [RFC/RFT PATCH v3] sched: automated per tty task groups
    From
    Date
    On Tue, 2010-11-16 at 16:03 +0100, Oleg Nesterov wrote:
    > On 11/16, Mike Galbraith wrote:
    > >
    > > On Tue, 2010-11-16 at 14:04 +0100, Oleg Nesterov wrote:
    > > > However, I must admit I dislike this check. Because, looking at this
    > > > code, it is not clear why do we check PF_EXITING. It looks as if it
    > > > is needed for correctness.
    > >
    > > Is _not_ needed I presume.
    > >
    > > I'll remove it, I'm not overly attached (a t t a..;) to it.
    >
    > Argh!
    >
    > I was wrong, it _is_ needed for correctness. Yes, it is always safe
    > to read the pointer, but
    >
    > > > Yes, sure, rq->lock should ensure signal->autogroup can't go away.
    > > > (even if it can be changed under us). And it does, we are moving all
    > > > threads before kref_put().
    > >
    > > (yeah)
    >
    > Exactly. And this means we can _only_ assume it can't go away if
    > autogroup_move_group() can see us on ->thread_group list.

    Aha!

    > Perhaps this deserve a commen (unless I missed something again).
    >
    > Mike, sorry for confusion.

    Oh no, thank you. I hadn't figured it out yet, was going to go back and
    poke rt kernel with sharp sticks. (exit can be one scary beast)

    -Mike



    \
     
     \ /
      Last update: 2010-11-16 16:45    [W:0.022 / U:98.672 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site