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From: mulyadi.santosa@gmail.com (Mulyadi Santosa)
To: kernelnewbies@lists.kernelnewbies.org
Subject: PR Value in the top command
Date: Tue, 22 Mar 2016 12:28:06 +0700	[thread overview]
Message-ID: <CAGdaadbkojYvTJu1hYeFrpg=+QPLbO+HaZmCo1-DVXNOp9Lo5Q@mail.gmail.com> (raw)
In-Reply-To: <CAGM3cC5zmUVOX4+wDaijg27G2HucmSNvLbSUUybe2sHjz+d-+Q@mail.gmail.com>

On Mon, Mar 21, 2016 at 6:37 PM, Vishwas Srivastava <vishu.kernel@gmail.com>
wrote:

> Hi All,
>             i was trying to understand the the meaning of the PR field in
> the "top" command.
>
> PR field is the kernel notion of importance of a task.
> It is loosely coupled with the "nice" value, which is a user-space concept.
> Roughly they are related with..
>
> PR=20+nice   (-20<= nice <=19)
> which means, PR can never go below 0.
>
> As an experiment to understand this even more, i created an user-app with
> real-time scheduling policy (SCHED_FIFO) and ran this application.
>
> while the application was running i triggerred "top" and what i see that
> the PR value for my application displays a -ve value.
> what does this mean.
> If at all this is correct, what are the valid range of PR which i should
> expect?
>
>
Quick answer: have you check and read sched_setscheduler() in detail,
especially part that explains about SCHED_FIFO?

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
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      reply	other threads:[~2016-03-22  5:28 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-21 11:37 PR Value in the top command Vishwas Srivastava
2016-03-22  5:28 ` Mulyadi Santosa [this message]

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