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Date: Thu, 6 Mar 2014 23:13:33 +1100
From: Kevin Easton <kevin@guarana.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>, Khalid Aziz <khalid.aziz@oracle.com>,
        One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
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        peterz@infradead.org, akpm@linux-foundation.org,
        viro@zeniv.linux.org.uk, oleg@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [RFC] [PATCH] Pre-emption control for userspace
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On Tue, Mar 04, 2014 at 04:51:15PM -0800, Andi Kleen wrote:
> Anything else?

If it was possible to make the time remaining in the current timeslice
available to userspace through the vdso, the thread could do something like:

if (sys_timeleft() < CRITICAL_SECTION_SIZE)
    yield();
lock();

to avoid running out of timeslice in the middle of the critical section.

    - Kevin