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From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Khalid Aziz <khalid.aziz@oracle.com>
Cc: tglx@linutronix.de, corbet@lwn.net, mingo@redhat.com,
	hpa@zytor.com, peterz@infradead.org, riel@redhat.com,
	akpm@linux-foundation.org, rientjes@google.com,
	ak@linux.intel.com, mgorman@suse.de, liwanp@linux.vnet.ibm.com,
	raistlin@linux.it, kirill.shutemov@linux.intel.com,
	atomlin@redhat.com, avagin@openvz.org, gorcunov@openvz.org,
	serge.hallyn@canonical.com, athorlton@sgi.com, oleg@redhat.com,
	vdavydov@parallels.com, daeseok.youn@gmail.com,
	keescook@chromium.org, yangds.fnst@cn.fujitsu.com,
	sbauer@eng.utah.edu, vishnu.ps@samsung.com, axboe@fb.com,
	paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice (was: Pre-emption control for userspace)
Date: Tue, 25 Nov 2014 15:42:38 +0530	[thread overview]
Message-ID: <20141125101238.GA19795@linux.vnet.ibm.com> (raw)
In-Reply-To: <1416862595-24513-1-git-send-email-khalid.aziz@oracle.com>

> 
> - Request to borrow timeslice is not guranteed to be honored.
> - If the task is allowed to borrow, kernel will inform the task
>   of this. When this happens, task must yield the processor as soon
>   as it completes its critical section.
> - If the task fails to yield processor after being allowed to
>   borrow, it is penalized by forcing it to skip its next time slot
>   by the scheduler.
> - Task is charged additional time for the borrowed timeslice as
>   accumulated run time. This pushes it further down in consideration
>   for the next task to run.
> 

Is there a way for us to identify if the lock is contended?
Because it may not be prudent to allow a task to borrow timeslice for a
lock which isnt contended.

-- 
Thanks and Regards
Srikar Dronamraju


  parent reply	other threads:[~2014-11-25 10:13 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-24 20:56 [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice (was: Pre-emption control for userspace) Khalid Aziz
2014-11-24 22:43 ` Andi Kleen
2014-11-24 23:20   ` Khalid Aziz
2014-11-24 23:35 ` Thomas Gleixner
2014-11-25  2:12   ` Davidlohr Bueso
2014-11-25  4:20   ` Mike Galbraith
2014-11-25 14:50     ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice Khalid Aziz
2014-11-25 17:46       ` Mike Galbraith
2014-11-25 19:38         ` Khalid Aziz
2014-11-25 14:45   ` Khalid Aziz
2014-11-25 18:27     ` Davidlohr Bueso
2014-11-25 19:23       ` Khalid Aziz
2014-11-25 19:40         ` Davidlohr Bueso
2014-11-25  2:03 ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice (was: Pre-emption control for userspace) Rik van Riel
2014-11-25  6:30   ` Davidlohr Bueso
2014-11-25 13:38     ` Rik van Riel
2014-11-25 14:52   ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice Khalid Aziz
2014-11-25 15:25     ` Rik van Riel
2014-11-25 17:22       ` Khalid Aziz
2014-11-25 17:45         ` Rik van Riel
2014-11-25 10:12 ` Srikar Dronamraju [this message]
2014-11-25 14:56   ` Khalid Aziz

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