linux-kernel - Re: sched_yield() call on Linux Kernel 2.6.39 is not behaving correct

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Message-ID: <1420773280.5340.16.camel@marge.simpson.net>
Date:	Fri, 09 Jan 2015 04:14:40 +0100
From:	Mike Galbraith <umgwanakikbuti@...il.com>
To:	Yogesh Ahire <yogesh02061983@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: sched_yield() call on Linux Kernel 2.6.39 is not behaving
 correct

On Thu, 2015-01-08 at 10:00 -0500, Yogesh Ahire wrote: 
> Thank you Mike. But I can see there are tasks with same priority and
> are runnable waiting for CPU, following is the output of
> /proc/sched_debug where you can see that the task "symphonyapp"
> continuously calls sched_yield() but there are other tasks which are
> ready to run are not getting CPU and are queued back.

Something terminally bad happened.  With that tasks vruntime (tree-key),
it's gonna try to yield for one hell of a long time before it succeeds.

-Mike

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