idle task check

[Mustafa Hussain]

I mean how can we use the pid in the scenario of finding the process that
is not used.
On 4 Jun 2015 16:00, "nick" <xerofoify at gmail.com> wrote:

>
>
> On 2015-06-04 08:52 AM, Mustafa Hussain wrote:
> > Ok, everything is clear except one thing what we will do exactly with
> (pid)
> > s?
> > On 4 Jun 2015 15:40, "nick" <xerofoify at gmail.com> wrote:
> >
> Its used in task struct to create a doubly linked list with init/systemd
> being the head or first process and the others linked in other of their
> hierarchy.
> Nick
> >>
> >>
> >> On 2015-06-04 08:34 AM, Mustafa Hussain wrote:
> >>> great, How can I check if this running task is used or not.. I mean by
> >> not
> >>> used that the task is running but not used by the user
> >>>
> >>>
> >> Here is the issue through in order to find out what tasks the user is
> >> running we
> >> need to known the exact pid(s) each time. This is next to impossible to
> do
> >> without
> >> writing a syscall and that’s a little beyond you if your asking about
> the
> >> scheduler.
> >> However, there may be a debugging feature in perf or other tool that
> does
> >> this, you
> >> can google to see if something wrote a tool or kernel module for this.
> >> Nick
> >>> On June 4, 2015 8:22:03 AM EDT, Mustafa Hussain <
> >> mustafa.hussain93 at gmail.com>
> >>> wrote:
> >>>> So I was just thinking about if i did this i can close apps that is
> >>>> running
> >>>> and user don't use them..
> >>>> On 4 Jun 2015 14:59, "Nicholas Krause" <xerofoify at gmail.com> wrote:
> >>>>
> >>> That's not a idle task,  that's a task in the
> >>> TASK_INTERRUPTIBLE  or TASK_RUNNING phase.
> >>> Nick
> >>>>>
> >>>>>
> >>>>> On June 4, 2015 7:56:30 AM EDT, Mustafa Hussain <
> >>>>> mustafa.hussain93 at gmail.com> wrote:
> >>>>>> All i am trying to do is to detect idle task and remove it from the
> >>>>>> running
> >>>>>> queue or deactivate it.
> >>>>> There is no reason  for that.  The idle tasks are only ever scheduled
> >>>> when
> >>>>> there is no other processes able to
> >>>>> run.  So trying to remove them is a
> >>>>> bad idea.
> >>>>> Nick
> >>>>>> Thank you for your patience :)
> >>>>>> On 4 Jun 2015 14:51, "Nicholas Krause" <xerofoify at gmail.com> wrote:
> >>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>> On June 4, 2015 3:35:25 AM EDT, Mustafa Hussain <
> >>>>>>> mustafa.hussain93 at gmail.com> wrote:
> >>>>>>>> System crashes,  system can not start
> >>>>>>>>
> >>>>>>> I was not thinking and this schedules the idle thread. What are
> >>>> you
> >>>>>> trying
> >>>>>>> to accomplish through.
> >>>>>>> Nick
> >>>>>>>>
> >>>>>>>> On June 3, 2015 9:41:52 PM EDT, Mustafa Hussain
> >>>>>>>> <mustafa.hussain93 at gmail.com>
> >>>>>>>> wrote:
> >>>>>>>>> i want to dequeue the idle task how can i do this ?
> >>>>>>>> Why there is no point.  Clearly your asking questions in order to
> >>>>>> learn
> >>>>>>>> the
> >>>>>>>> scheduler.
> >>>>>>>> If your interested in learning it I  can help but,  you need to
> >>>>>> think
> >>>>>>>> about
> >>>>>>>> what you
> >>>>>>>> trying to accomplish first.
> >>>>>>>> Nick
> >>>>>>>>
> >>>>>>>>> On Thu, Jun 4, 2015 at 3:40 AM, Mustafa Hussain
> >>>>>>>>> <mustafa.hussain93 at gmail.com
> >>>>>>>>>> wrote:
> >>>>>>>>>
> >>>>>>>>>> Hi nick,
> >>>>>>>>>> i applied your suggested edit and i got "bad: scheduling from
> >>>> the
> >>>>>>>>> idle
> >>>>>>>>>> thread!"
> >>>>>>>>>> how can i solve this ?
> >>>>>>>>>>
> >>>>>>>>>> On Wed, Jun 3, 2015 at 12:29 AM, nick <xerofoify at gmail.com>
> >>>>>> wrote:
> >>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>> On 2015-06-02 06:25 PM, Valdis.Kletnieks at vt.edu wrote:
> >>>>>>>>>>>> On Tue, 02 Jun 2015 23:38:48 +0200, Mustafa Hussain said:
> >>>>>>>>>>>>
> >>>>>>>>>>>>>> /*Check if the pointer pointing to the idle class is
> >>>> equal
> >>>>>> to
> >>>>>>>>> prev's
> >>>>>>>>>>>>>> sched_class*/
> >>>>>>>>>>>>>> if(prev->sched_class == idle)
> >>>>>>>>>>>>>> After this condition you can just:
> >>>>>>>>>>>>>> printk(KERN_INFO "Prev is equal to idle_sched_class,now
> >>>>>> running
> >>>>>>>>> the
> >>>>>>>>>>> idle
> >>>>>>>>>>>>>> sched_class\n");
> >>>>>>>>>>>>
> >>>>>>>>>>>> Hopefully, you didn't take Nick's advice without thinking
> >>>>>> about
> >>>>>>>>> it....
> >>>>>>>>>>>>
> >>>>>>>>>>>> As I type this, powertop tells me:
> >>>>>>>>>>>>
> >>>>>>>>>>>> Summary: 821.8 wakeups/second,  0.0 GPU ops/seconds, 0.0
> >>>> VFS
> >>>>>>>>> ops/sec
> >>>>>>>>>>> and 18.8% CPU use
> >>>>>>>>>>>>
> >>>>>>>>>>>> That printk is going to spam your dmesg pretty hard.
> >>>>>>>>>>>>
> >>>>>>>>>>>> A better question is:
> >>>>>>>>>>>>
> >>>>>>>>>>>> If prev is about to go idle, *what do you want to do*?
> >>>> (Hint:
> >>>>>>>>> newer
> >>>>>>>>>>>> kernels already do a bunch of stuff when a cpu/core goes
> >>>> idle,
> >>>>>>>> you
> >>>>>>>>>>>> probably want to make sure you're not working against
> >>>>>> something
> >>>>>>>>> here...)
> >>>>>>>>>>>>
> >>>>>>>>>>> I didn't account for rate limiting the debug messages, forgot
> >>>>>> about
> >>>>>>>>> that
> >>>>>>>>>>> . :)
> >>>>>>>>>>> I do agree his question is not the best but he wanted a
> >>>> answer
> >>>>>> so I
> >>>>>>>>>>> decided
> >>>>>>>>>>> to just give him a answer that works for his learning.
> >>>>>>>>>>> Nick
> >>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>
> >>>>>>>> --
> >>>>>>>> Sent from my Android device with K-9 Mail. Please excuse my
> >>>> brevity.
> >>>>>>>
> >>>>>>> --
> >>>>>>> Sent from my Android device with K-9 Mail. Please excuse my
> >>>> brevity.
> >>>>>>>
> >>>>>
> >>>>> --
> >>>>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
> >>>>>
> >>>
> >>> --
> >>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
> >>>
> >>
> >
>
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