lkml.org 
[lkml]   [2017]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC v5 2/9] sched/deadline: improve the tracking of active utilization
    On Fri, 24 Mar 2017 22:31:46 -0400
    Steven Rostedt <rostedt@goodmis.org> wrote:

    > On Fri, 24 Mar 2017 22:47:15 +0100
    > luca abeni <luca.abeni@santannapisa.it> wrote:
    >
    > > Ok... Since I am not good at ascii art, would it be ok to add a
    > > textual description? If yes, I'll add a comment like:
    > > "
    > > The utilization of a task is added to the runqueue's active
    > > utilization when the task becomes active (is enqueued in the
    > > runqueue), and is removed when the task becomes inactive. A task
    > > does not become immediately inactive when it blocks, but becomes
    > > inactive at the so called "0 lag time"; so, we setup the "inactive
    > > timer" to fire at the "0 lag time". When the "inactive timer"
    > > fires, the task utilization is removed from the runqueue's active
    > > utilization. If the task wakes up again on the same runqueue before
    > > the "0 lag time", the active utilization must not be changed and
    > > the "inactive timer" must be cancelled. If the task wakes up again
    > > on a different runqueue before the "0 lag time", then the task's
    > > utilization must be removed from the previous runqueue's active
    > > utilization and must be added to the new runqueue's active
    > > utilization. In order to avoid races between a task waking up on a
    > > runqueue while the "inactive timer" is running on a different CPU,
    > > the "dl_non_contending" flag is used to indicate that a task is not
    > > on a runqueue but is active (so, the flag is set when the task
    > > blocks and is cleared when the "inactive timer" fires or when the
    > > task wakes up).
    >
    > Sure, the above is great if you never want anyone to read it ;)
    >
    > Can you please break it up a little. My head starts to spin by the
    > third line down.

    Ok... Maybe finding a clean and understandable way to explain the
    above sentence is something that can be done at the OSPM summit?



    Thanks,
    Luca

    \
     
     \ /
      Last update: 2017-03-27 10:20    [W:3.900 / U:0.068 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site