From: Srikar Dronamraju <srikar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: Khalid Aziz <khalid.aziz-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org,
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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-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
>
> - 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
WARNING: multiple messages have this Message-ID (diff)
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
next prev parent reply other threads:[~2014-11-25 10:12 UTC|newest]
Thread overview: 30+ 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
[not found] ` <20141124224302.GL10824-KWJ+5VKanrL29G5dvP0v1laTQe2KTcn/@public.gmane.org>
2014-11-24 23:20 ` Khalid Aziz
2014-11-24 23:20 ` Khalid Aziz
2014-11-24 23:35 ` Thomas Gleixner
2014-11-25 2:12 ` Davidlohr Bueso
2014-11-25 2:12 ` Davidlohr Bueso
2014-11-25 4:20 ` Mike Galbraith
[not found] ` <1416889208.4335.127.camel-sZ+7a5bGyC/1wTEvPJ5Q0F6hYfS7NtTn@public.gmane.org>
2014-11-25 14:50 ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice Khalid Aziz
2014-11-25 14:50 ` Khalid Aziz
2014-11-25 17:46 ` Mike Galbraith
[not found] ` <1416937564.3512.15.camel-sZ+7a5bGyC/1wTEvPJ5Q0F6hYfS7NtTn@public.gmane.org>
2014-11-25 19:38 ` Khalid Aziz
2014-11-25 19:38 ` Khalid Aziz
2014-11-25 14:45 ` Khalid Aziz
[not found] ` <54749617.5030309-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-11-25 18:27 ` Davidlohr Bueso
2014-11-25 18:27 ` Davidlohr Bueso
2014-11-25 19:23 ` Khalid Aziz
[not found] ` <5474D71E.8070603-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-11-25 19:40 ` Davidlohr Bueso
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
[not found] ` <54749F77.50905-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-25 17:22 ` Khalid Aziz
2014-11-25 17:22 ` Khalid Aziz
2014-11-25 17:45 ` Rik van Riel
[not found] ` <1416862595-24513-1-git-send-email-khalid.aziz-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-11-25 10:12 ` Srikar Dronamraju [this message]
2014-11-25 10:12 ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice (was: Pre-emption control for userspace) Srikar Dronamraju
2014-11-25 14:56 ` [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice Khalid Aziz
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